Playing around with some integrals, I stumbled across a cute one: $$ \int_{0}^{\infty}\sin(x)\sin\left(\frac{1}{x}\right)\,dx $$ Substituting $z=\frac1x$ gives $$ \int_{0}^{\infty}\sin(x)\sin\left(\frac{1}x\right)\,dx = \int _0^{\infty} \frac{\sin(z)\sin\left(\frac{1}{z}\right)}{z^2}\,dz, $$which Mathematica gave as $\frac{\pi}{2}J_1(2)$, where $J_1$ is the . I'd be curious to see a derivation of this, as well as a rigorous proof the integral converges.

I have stumbled onto an interesting integral$$\int_0^\infty \sin(x)\sin\left(\frac{1}{x}\right)dx$$ which I noticed graphically that it appears to be $1$, but I have no idea on how to evaluate it. Maybe it could be done with the use of Bessel Functions? Any help is appreciated.


When this code runs, the char variables contained in the array do not update and remain a blank space. The TicTacToe board prints in the correct format. Am I missing something obvious? Scanner scan = new Scanner(System.in);         String pos;         boolean win = false;                   char tl = ' '; char tm = ' '; char tr = ' ';         char ml = ' '; char mm = ' '; char mr = ' ';         char bl = ' '; char bm = ' '; char br = ' ';                  // INITIALIZE ARRAY         char[] tic = new char[15];         tic[0] = tl; tic[1] = '|'; tic[2] = tm; tic[3] = '|'; tic[4] = tr;         tic[5] = ml; tic[6] = '|'; tic[7] = mm; tic[8] = '|'; tic[9] = mr;         tic[10] = bl; tic[11] = '|'; tic[12] = bm; tic[13] = '|'; tic[14] = br;                               System.out.println("Player 1: Make your move!");             System.out.println("Choose between: TL TM TR ML MM MR BL BM BR");                      pos = scan.next();                      if(pos == "TL") {tl = 'X'; }             if(pos == "TM") {tm = 'X'; }             if(pos == "TR") {tr = 'X'; }             if(pos == "ML") {ml = 'X'; }             if(pos == "MM") {mm = 'X'; }             if(pos == "MR") {mr = 'X'; }             if(pos == "BL") {bl = 'X'; }             if(pos == "BM") {bm = 'X'; }             if(pos == "BR") {br = 'X'; }                          System.out.println("Player 2: Make your move!");             System.out.println("Choose between: TL TM TR ML MM MR BL BM BR");                          pos = scan.next();                          if(pos == "TL") {tl = 'O'; }             if(pos == "TM") {tm = 'O'; }             if(pos == "TR") {tr = 'O'; }             if(pos == "ML") {ml = 'O'; }             if(pos == "MM") {mm = 'O'; }             if(pos == "MR") {mr = 'O'; }             if(pos == "BL") {bl = 'O'; }             if(pos == "BM") {bm = 'O'; }             if(pos == "BR") {br = 'O'; }                          // PRINT BOARD             for(int i = 0; i <= 14; i++)             {                     System.out.print(tic[i]);                                          if(i == 4 || i == 9)                      {                         System.out.println();                     }                                                   }  I was messing around and realized that I have no idea how to resolve this issue

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I would like to provide a horizontal scroll to a textarea in my HTML page. The scroll should appear without wrapping, if I type a long line without a line break. A few friends suggested using overflow-y CSS attribute, which did not work for me. The browsers that I use are IE 6+ and Mozilla 3+.

my simple textarea doesn't show a horizontal bar when text overflows. It wraps text for a new line. So how do I remove wordwrap and display horizontal bar when text overflows?


It had been some times I joined Stackoverflow. And it is really a massive stage for knowledge sharing.   Stackexchange posts support  syntax. In  we can insert . Like if we write-  :octocat: :+1: :book:   these appear-          Does Stackexchange have something like this?

Stack Exchange uses Markdown, but unlike so many other sites (e.g. GitHub, Discourse, Slack) that use Markdown, we don't support Emoji. I'd like to be able to write :smile:, :thumbsup:, :heart: or even :poop: and have it render correctly on all Stack Exchange sites.    See the  for more examples.  To clarify - I'm not asking for emoji character support.  We can already do emoji with Unicode characters, like this:  ☺ 👍 ❤ 💩  I'm asking specifically that the markdown engine recognize the emoji tags like :smile:.  It would be great if it rendered with better graphics, but rendering with their text equivalents would also be acceptable.


I have a basic question on the definition of "population" in statistics.   Use this as example: the height of everyone in U.S.  In my study of probability and statistics course long time ago majoring engineering, the population means all of the heights of all people in U.S.  Now I'm taking courses to get certification as high school math teacher. In my math education class, the professor says I'm wrong. She wrote:  You say "population refers to the data being studied, which is the height of each student. The “population” is a collection of the heights of the students."  This is not quite correct - the heights are considered the variable of the population/observational units/individuals being studied. The population is not the data values.  I talked to my professor again, and am sure that she says that in this case the population is all people.  I checked on internet, and saw both ways (mine and my professor's. I hope to get some clarity and answer here.

What is the difference between a population and a sample? What common variables and statistics are used for each one, and how do those relate to each other?


I work as a freelancer. I am an online teacher.  I get my payment by western union or to my bank account.  I wanted to know how I can prove the origin of my money in my application.  I applied for a short term visa and it was refused because I didn’t put the origin of my money.

I have applied recently for a general visitor visa to the UK to spend 10 days during Christmas with my British unmarried partner and it has been turned down.   The Entry Clearance Officer stated on his refusal notice the following:     I note that you have never previously travelled to the UK or any country with similar immigration requirements and you therefore do not have a history of travel and compliance to consider.      You have submitted an employment letter to confirm your occupation in KSA but I am required to also assess your personal, domestic and economic circumstances in determining whether you are genuine visitor travelling to the UK for the period and purpose you state.      You claim an income of SAR ........ per month which equal ........ GBP and from the evidence submitted this appears to be your sole source of income.   I note that this monthly income is reflected on your bank statements. However, the bank statement you have presented show a recent large deposit that are in excess of your stated income and inconsistent with the account history. You haven't provided evidence toward the origin of this recent deposit and in the absence of reasonable evidence I am not satisfied that these bank statements accurately reflect your personal circumstances.      In view of the above, I am not satisfied you have demonstrated that your circumstances are as you claim and therefore I am not satisfied that you're travelling to the UK for the period and purpose you stated. 41(i)and(ii).   Its true that I have deposited that sum of money right before I apply and it was a commission I received from work earlier this month.   So, could you please give me your advice on the above as I am planning to apply again soon. and how to avoid my application being refused again?


I’ve been using 18.04 server for several months to host a few services.  I’ve recently started diving into Docker and in many of the guides I encounter they give command line calls that use NetworkManager, which is not installed with server.  This is annoying to the point I’m asking myself why I’m not using Desktop.  I chose the server flavor mostly because I like the geekiness of the command line.  I also figured it is less resource intensive than its Desktop counterpart.  I know I can install Desktop and still use the command line, but what am I “saving” by using Server over Desktop, especially if both versions use the same kernel?  If I’m using the machine as a server, how much is Desktop costing me in terms of resources and performance?

What's the difference between the server version of Ubuntu and the desktop version?


I have a Canon 60D EOS. I can not change the shutter speed higher than 1/250. I updated the firmware to 1.1.1 but nothing changed. Also I updated the Magic Lantern firmware but still I see the same problem. How can I fix this?  Is it related to my camera or lens?

Sometimes in bright backlight and with large aperture (f2.8) I want flash at high shutter speeds.  But when I pop the flash up on D7000 it caps the shutter speed to 1/250th, which overexposes the shots and makes everything look like a nuclear bomb just went off.  What's the logic behind the limiting of the shutter speed when using flash? Is there anything I can do to get flash  + faster shutter speeds?


I installed a fresh copy of ubuntu 12.04. I started the machine and was able to login successfully the first time. Upon any restarts I see a black screen, then I hear the audio drum roll that is played when it is time to login, I however only have a black screen. I then loaded up grub loader by holding shift during booting and set to nomodeset(I believe this goes low graphics default). I am able to boot in. I downloaded and ran boot repair, below you can find the boot report. Upon running boot repair and restarting it boots in fine the first time. However on subsequent attempts it will just go to the black screen. Please Help!

I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:


Suppose Question A had a bounty placed on it, and then an exact duplicate Question B with answers on it (that were written after the bounty was set) was migrated from a different site, and merged with it.  Whether through the automatic selection or through manual awarding, the bounty is awarded to an answer whose author does not have an account here, because they answered Question B.  Can this happen, and if so, what happens to the reputation? Does it get lost? Awarded on association?

I somehow think this is a dupe, so sorry if it is.  My search-fu is turning up empty...  Do migrated questions retain bounty history?  For example, say a question has a bounty set on one site before enough people vote it closed and migrate it.  The bounty expires on the one site, then it gets enough close votes to migrate.  Is it no longer possible to accept that answer on the target site since the bounty on the first site expired?  I know this probably doesn't happen that often on SO, but I've seen it a few times on SF.  Mainly when the OP doesn't want the question migrated....


I am trying to install Ubuntu 14.04 using wubi ,I had a 12.04  installation on this laptop.Some how I have removed the old one and now installing new.I downloaded  Ubuntu 14.04-1-desktop-amd64 ISO and extracted wubi from it kept both ISO and wubi in same folder,   I noticed each time wubi will start downloading ISO from internet.I let it do for 2-4 days some how thir process did not result in any fruitful thing.  Now I found on some thread people facing this issue will disconnect their internet connection and wubi installer will start installation from downloaded ISO, in my case also I disconnected lan wire from laptop and then using wubi installation began.  But at the end when I boot then I am getting errors as / is not found/not mounted press I to ignore S to Skip or M for manual recovery.  /tmp is not found press I to ignore S to Skip or M for manual recovery.  I do not know how to manually fix it. Igonoring or skipping the process leads me to borne shell based login prompt with no X window interface at all. How ever during install it downloaded every thing it possibly could because once installation had begun I had connected the lanwire. After multiple such installation attempts I have finally failed to install Ubuntu 14.04 on my system. (12.04 was running fine I have lost that now) .What should I do now?

I recently installed Ubuntu 14.04 using WUBI and after installation when it booted it showed an error:   Serious errors were found while checking the disk drive for /.    There were three options:   press [I] to ignore, press [S] to skip mounting and press [M] to mount manually.    After I pressed I, it showed /tmp could not be mounted and my Ubuntu isn't booting.   Can anybody please guide me to how to solve this problem?


Hai all I am using Hibernate, java and Sql server for creating an application. And while doing this I have come across a problem where Union is not supported by HQL. For me the following code works in native SQL but it is not working when I am dealing with HQL.  SQL  select inttestid,testname from LAB_TEST_SERVICES where inttestid in(select inttestid from dbo.LAB_SPECIMEN_MAPPING union select intprotestid from LAB_PROFILE_TEST_LIST) and inttestid not in(select inttestid from LAB_TARIFF_MAPPING);   HQL  String h = "From SERVICES_TYPE_POJO lst where lst.inttestid in(select smp.inttestid from SPECIMEN_MAPPING_POJO smp union select ptl.intprotestid from PROFILE_TEST_LIST_POJO ptl) and lst.inttestid not in(select tmp.inttestid from TARIFF_MAPPING_POJO tmp)";   Can anyone help me with changing the SQL to HQL. Thanks in advance.

What alternatives do I have to implement a union query using hibernate? I know hibernate does not support union queries at the moment, right now the only way I see to make a union is to use a view table.  The other option is to use plain jdbc, but this way I would loose all my example/criteria queries goodies, as well as the hibernate mapping validation that hibernate performs against the tables/columns.


If someone has no way to tell who a person's parents are/were (no paperwork), is there a way to tell for a Wizard if someone is a Squib or a Muggle? Or are they 100% functionally equivalent and only different as far as bureaucracy is concerned?

‘And what on earth’s a Squib?’ said Harry.   To his surprise, Ron stifled a snigger.   ‘Well – it’s not funny really – but as it’s Filch ...’ he said. ‘A Squib is someone who was born into a wizarding family but hasn’t got any magic powers. Kind of the opposite of Muggle-born wizards, but Squibs are quite unusual. If Filch’s trying to learn magic from a Kwikspell course, I reckon he must be a Squib. It would explain a lot. Like why he hates students so much.’ Ron gave a satisfied smile. ‘He’s bitter.’   Chamber of Secrets - pages 110-111 - British Hardcover   If a Squib is 'kind of the opposite of a Muggle-born wizards' wouldn't that make a Squib more Muggle than wizard? Does a Muggle strictly have to be born to Muggle parents to be considered a Muggle, or can the lack of magic render a person, even of wizarding parentage, a Muggle?  Hermione can say in all truthfulness that she is a 'Muggle-born witch.' The nickname (albeit derogatory) for a Muggle-born is 'Mudblood.' Filch can say in all truthfulness that he is a 'wizarding-born non-magic person,' which, according to Hagrid is a Muggle.  'Squib' may be derogatory in the same way as 'Mudblood' is. Neville laments his family thought he was a Squib when he showed no magical tendencies as a child; the Longbottoms were so rattled at the thought of Neville being a Squib that they, among other things, threw him out a second-story window to see if he would bounce. So could 'Squib' actually be a derogatory term meaning the opposite of 'Mudblood'? After all, the Ministry doesn't allow Squibs to register as magical beings, and many Squibs are schooled and trained in Muggle professions. Squibs don't get a Hogwarts letter.    Wizards can be born to Muggles. Can Muggles be born to wizards?  ETA 11.22.14: In regard to this question, I was glancing through Philosopher's Stone, and I came across this, that Neville said:     ‘Well, my gran brought me up and she’s a witch,’ said Neville, ‘but the family thought I was all Muggle for ages. My great-uncle Algie kept trying to catch me off my guard and force some magic out of me – he pushed me off the end of Blackpool pier once, I nearly drowned – but nothing happened until I was eight.’   Philosopher's Stone - page 93 - Bloomsbury - chapter seven, The Sorting Hat   Could what Neville says contribute to the theory and/or conclusion that Squibs are, or are not, Muggles? How do we apply what Neville said?


I think the problem I have has something to do with overlapping faces, because the pattern becomes more repeated each time i subdivide the object. I have tried to delete double vertices and recalculate normals to no end. However, the pattern disappears when i go into Sculpt mode, and the pattern stays no matter what material I assign to it. The pattern is still visible when the object is rendered.

Here is the viewport in material view.  The node setup is just a PNG texture into a diffuse shader.    And this is in rendered view.  I've tried using environmental lighting as well as a directional light, and while the lit parts become brighter/washed out, the darker parts stay dark.  Normals are correct and there is no z-fighting.  Ambient Occlusion is not enabled.  Changing to Flat shading makes it worse.    Update:  Any modifier that alters the mesh (bevel, subdivide, etc) make the problem go away instantly.


I cannt mountig to another part of my hdd which is windows10 and i lost my windows password....when i try to mount it to get my pictures which are saved there... the messege i get is:  Error mounting /dev/sda5 at /media/fareidon/Windows8_OS: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000" "/dev/sda5" "/media/fareidon/Windows8_OS"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sda5': Operasjonen er ikke tillatt The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.   what shall i do it without the windows password..thanks for helping    i tried this comand sudo mount -t ntfs -o uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000 /dev/sda5 /media/fareidon/Windows8_OS  but its ask me the password which i said i forgot it!  and tried this comand to:  mount  /dev/sda5 /media/fareidon/windows8_os -o ro  the answer i get :  mount: only root can use"--options"optios  somebody can help,still i cannt mount,the big problem is the windows password!! when i comand any command,it ask me the password of windows which i forgott!!

Whenever I boot Ubuntu, I get a message that it cannot mount my windows partition, and I can choose to either wait, skip or manually mount.  When I try to enter my Windows partition through Nautilus I get a message saying that this partition is hibernated and that I need to enter the file system and properly close it, something I have done with no problem so I don't know why this happens.    Here's my partition table, if any more data is needed please let me know.     Device Boot      Start         End      Blocks   Id  System /dev/sda1            2048    20000767     9999360   83  Linux /dev/sda2        20002814   478001151   228999169    5  Extended /dev/sda3   *   478001152   622532607    72265728    7  HPFS/NTFS/exFAT /dev/sda4       622532608   625141759     1304576   82  Linux swap / Solaris /dev/sda5        20002816   478001151   228999168   83  Linux


If you assume an interstellar spacecraft of 100 m in diameter traveling to the nearest star - that ship would plow through 3 x 10^20 m^3 of interstellar space.  At 0.5 c the energy release of such a spaceship encountering a piece of space "dust" weighing (~0.01g) becomes significant. Only one such impact would be enough to cause severe spacecraft damage given the kinetic energy involved (150,000 Joules).  This collision would explode like a pinpoint bomb (30 g of TNT - one half the charge in a hand grenade).  So, what are the chances of such a space ship encountering such a interstellar grain of dust in traveling to the nearest star?

It is known that one of the main problems of interstellar flight is a presence of matter between stars in form of very fine dust and huge asteroids. Which can slowly (or fast) destroy any ship.  What are the most recent estimations about the concentration and size distribution of interstellar matter? From very small to high scales. Particularly i am interested in the local group of stars.  Update II: smallest object still named as a meteorite (Yamato8333) is about 12mg in mass and roughly 2mm in diameter.  Update: Below is an image of an interplanetary dust particle (IDP, not Yamato8333).    "IDP composed of nanometre-sized mineral grains and organic matter." (Credit: N. Spring)  Original post .


is there any integrated circuit HEX to 7 segment decoder for a common anode 7 SEG display that generates codes to display hex digits from 0 to F as shown in the photo. Thanks

I'm trying to display a 4-bit binary number on a 7 segment LED as a hexadecimal number (0-F). I have an assortment of 7400 series ICs including the 7447. But that one only works for BCD (0-9). The 7400 series doesn't seem to have a hex to 7-segment decoder and I don't have one on hand.  So I figure I'd have to build my own. The datasheet for a 7447 comes with the internal circuitry but I couldn't find a similar circuit for hex to 7-segment. I did K-diagrams for each LED segment by hand but the terms are rather large, much larger than for BCD.  Does anyone have a finished circuit for this that I can check my work against?  Does anyone have an optimized circuit for this that takes advantage of common subterms? There aren't many duplicate terms (like A0 & ~A1 & A2) but maybe using (A0 & A2) & ~A1 would allow sharing the (A0 & A2) subterm and overall reduce the gate count.  Or maybe some tricks to use NAND, NOR or XOR gates for some parts?  I don't care about different path length or races in the circuit as it's only going to drive LEDs and should be far too quick to see any of that.


How can I measure the length of the side of a polygon that touches another feature (calculate from A to B on the image below)?  I'm creating and measuring lines to figure out the lenght of the 'intersection' and I wish that was a easier method using a geoprocessing tool.  How can it be done?  I don't have programing skills and I am using ArcGIS 10.2.2.

I want to take geometric intersection of line and polygon shapefile. ArcPy has a tool:  arcpy.Identity_analysis   but it is available with "ArcGIS for Desktop Advanced" and I have "ArcGIS for Desktop Basic".   Is there any alternative tool that I can try?


I'm looking for a word that describes an entity having only knowledge of its own existence, but no one else's.  The closest I have now is autognostic, auto being "self" and gnostic being "having knowledge", but I think autognostic might just mean "self-aware" and not "exclusively aware of oneself".  Does such a word exist?

What do you call someone that believes he is actually the only living being and that everyone and everything that exist (besides him self) is a state of his own mind? I am not referring to a


I am traveling to the USA on KLM. I have an 8-hour stopover at Amsterdam. I want to see tourist attractions in Amsterdam. I am an Indian national. Do I need a transit visa?

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


Imagine that you have the following list. keys = ['name', 'age', 'food'] values = ['Monty', 42, 'spam']  What is the simplest way to produce the following dictionary? a_dict = {'name': 'Monty', 'age': 42, 'food': 'spam'}


Say I have #FF3154 (as red). How could I come up with palette in which all the colors (different hue, as in orange, yellow, blue, etc...) are in harmony with that specific red, that is, all share the same saturation level.  Is there any software of automating such process?  Thanks a lot!

Let's consider three colors: Red, Green and Blue. For blue I created a specific shade, something like #F2F5F7. If you see this color, it has a certain level of shade, brightness and saturation value of blue.  I want to create the same equivalent color but for Green and Red, how to get that?


I mostly say "no problem" when I do something and people thank me. I read somewhere that this is not always correct as it shows like I spent no effort which is not always the case and sometimes it's very the opposite. I was advised I should be saying "always welcome" and "glad to help". But it still not appropriate in some cases (for example, when it's the boss who thanks me I don't think I should be saying that). What could be other possible answers in such situation? The more variants the better because I feel like I am reusing the same sentences over and over.

Is "you are welcome" more polite than "no problem"?  What is the general proper reply to a thank-you?


I run an OLS, after check residuals, they are normally distributed, mean is zero with some randomness. But after the autocorrelation plot shows significant correlations to 15+ lags. What should I do next to avoid this autocorrelation?

In the Breusch-Godfrey test we use a model  $$ e_t = \varepsilon_t + \beta_1 \varepsilon_{t-1} + \dots+ \beta_p \varepsilon_{t-p}. $$  If we reject the null hypotesis of no serial auotocorrelation of the error, it means that the residuals follow an auto-regressive model of order ($p$).  If I want to avoid this problem, I must add a certain number of lags of the response variable $y$ as regressors in the original model. However, in some cases this method is not useful.   Are there other options to consider?


shows the "event" that is creating excitement.  It looks to the untrained eye like a single "blip" on a detector.  It appears to last less than a second.  It is, later in the answer, referred to as a "black hole merger".  Are we seriously saying that two black holes merged in under a second?

Recent reports claim that the gravitational waves detected by LIGO match up with the signal expected from two black holes merging as predicted by general relativity.  Additionally, the masses of both black holes were estimated. Questions:  How certain are we that the detected of gravitational waves are necessarily from two black holes merging?  Since supermassive black holes are typically at the center of a host galaxy, what happened to the galaxies that contained the two merging black holes?  For example, did their host galaxies merge?    Edit After reading the answers, I understand that the signals detected by LIGO are proof of the validity of gravitational wave generational artifacts as predicted by general relativity.  When additionally gravitational waves, caused by the merger of the supermassive black holes (those which ARE indeed located in the centers of the merging galaxies) will be detected, since mergers of galaxies could be observed by the methods independent of gravitational waves such as registering the fact of the quasar appearance (). Additional questions:  Could someone offer me the historical ASTRONOMY precedent when the second degree of inference (from the mathematical model, being associated with the theory of Physics) was accepted as the discovery of the astronomical object?  Could someone give a reference to trustable scientific publication, with the subject of study being discussion of requirements satisfying claim of astronomical discovery of an astronomical object?  Have independent scientific sources (outside of members of the LIGO team) analyzed methodology and results of the LIGO signal detection, and published their conclusions with regards of what was actually discovered?


I received a payment error during my ESTA application and still need to pay. The current application status for the last few hours shows:     THE PAYMENT STATUS COULD NOT BE DETERMINED AT THIS TIME.      PLEASE CHECK BACK LATER FOR THE PAYMENT STATUS.      Your application is not complete and will not be processed by CBP until the processing fee has been paid.      You must complete payment within 7 days.   The  says to click the payment button if have not paid, however there is no payment button, I guess because already started the payment process.  I tried creating a new application however get an error about an application already existing for my passport. The application will expire automatically in 7 days, however I leave in 5 days.    I tried calling their support number but couldn't get through, and their email support has a 2-3 week turnaround time.  Any ideas how to get the visa-waiver in time? Is there perhaps a way to cancel an ESTA application so can start a new one?


I have defined cap in   def fingerCursor(device):     global cap     global cap_height     global cap_width     cap = cv2.VideoCapture(device)         #cap.set(cv2.cap_PROP_FRAME_HEIGHT,720)         #cap.set(cv2.cap_PROP_FRAME_WIDTH,1280)     cap_height = cap.get(cv2.cap_PROP_FRAME_HEIGHT)     cap_width = cap.get(cv2.cap_PROP_FRAME_WIDTH)         #print(cap_height,cap_width)   But still whenever I am running this part of my code, it says cap not defined. It also has the same problem with cap_height and cap_width.  while(cap.isOpened()):         ## capture frame-by-frame         ret, frame_raw = cap.read()         while not ret:             ret,frame_raw = cap.read()         frame_raw = cv2.flip(frame_raw, 1)         frame = frame_raw[:round(cap_height),:round(cap_width)] # ROI of the image         cv2.imshow("raw_frame",frame)

What exactly are the Python scoping rules?  If I have some code:  code1 class Foo:    code2    def spam.....       code3       for code4..:        code5        x()   Where is x found?  Some possible choices include the list below:   In the enclosing source file In the class namespace In the function definition In the for loop index variable Inside the for loop   Also there is the context during execution, when the function spam is passed somewhere else. And maybe  pass a bit differently?  There must be a simple reference or algorithm somewhere.  It's a confusing world for intermediate Python programmers.


I'm looking for a way to get detailed data usage  in Windows 10, something that would show the usage hour by hour (or even minute by minute) for each application.  I know about the two methods described  but the first one only shows global data usage over 30 days (I need more details), and the second only shows data for built-in Windows app, and not for regular desktop apps.  Any suggestions?

There are many answers here detailing programs that will monitor and log internet usage for a pc, but I need that usage to be logged and broken down, detailing which applications consumed that data.  I've noted there are several that give a real-time feed of each application's data usage (NetLimiter, Win7 Resource Monitor), but I can't find one that will log such data.  Anyone know of one?  Need to track down which program is using up a friend's bandwidth!


I am trying to use a simulated "and" statement with egrep. Currently I have   egrep -i 'name.*policy'  which works only if the order of appearance is true. Alternatively, I can egrep -i 'name.*policy|policy.*name' . I want to see if there is a better way to use an "and statement that is not order specific.

I would like to get the multi pattern match with implicit AND between patterns, i.e. equivalent to running several greps in a sequence:  grep pattern1 | grep pattern2 | ...   So how to convert it to something like?  grep pattern1 & pattern2 & pattern3   I would like to use single grep because I am building arguments dynamically, so everything has to fit in one string. Using filter is system feature, not grep, so it is not an argument for it.    Don't confuse this question with:  grep "pattern1\|pattern2\|..."   This is an OR multi pattern match.


When defining a wrapfigure (or a minipage), I need to specify the width of the figure. Is there a possibility that this width is determined by the picture inside? For sake of an MWE, I'll use a tikzpicture. I don't want to chage the scale of the image since my image is used multiple times in the document, but in different variations and it should have the same scale all the time. \documentclass{article} \usepackage{wrapfig} \usepackage{lipsum} \usepackage{tikz} \usepackage[justification=centering]{caption} \begin{document} \begin{wrapfigure}{r}{5cm}     \centering     \begin{tikzpicture}         \draw (0,0)circle (2);     \end{tikzpicture}     \captionof{figure}{A circle} \end{wrapfigure} \lipsum[1] \end{document}  This looks bad:  Adding \centering improves a bit, but then I still have too much spacing left and right. I want to have an output like this:  (This was created using 4cm as width, but I don't want to guess the size of the image - easy for the circle, harder if you have a more complicated image) To  sum it up, is there an option to fit the width of a wrapfigure (or any environment, like a minipage) to an image without rescaling the image and without guessing the size? Edit: Not a duplicate of , since in this case the author knows the width of the image and therefore can specify it, I don't.

I'm trying to add a figure to my document. Because I want text to wrap around it, I use the wrapfigure environment:  \begin{wrapfigure}{r}{1cm}   \begin{center}     \includegraphics[width=1cm]{"My figure"}   \end{center}     \caption{A caption of my figure} \end{wrapfigure}   As you can see, I want my figure to be shrunk down (the file is quite large) so I set the width to 1 cm. But now I must also tell the wrapfigure to be 1 cm wide. Why can't wrapfigure just automatically be as wide as the figure it contains?


Everytime I try to make chicken fried rice like I get at the take out place it never tastes like it does when they make it. We all know the basic ingredients Should you put the eggs or the rice first

Everytime I try to make chicken fried rice like I get at the take out place it never tastes like it does when they make it. We all know the basic ingredients  Rice (1 day old), Chicken, Green Onions, Sprouts, Eggs, Soy Sauce, MSG (optional)  I have a wok and I cook it just like them, I've heard all sorts of things as to what the "missing" or "secret" ingredient is. Some say it's a different type of soy sauce (not the standard La Choy) that they use.   I've been searching for definitive answers for this for a long time. It seems no one knows or anyone who's worked in a chinese place doesn't wish to share the knowledge. I went as far as adding MSG thinking that was what made the take-out place's Fried Rice taste different. MSG helps (sold as Accent Flavor Enhancer in your spice aisle) but that's not it.


let N be normal subgroup of group G. show that centralizer of N in G is also normal subgroup of G. I am unable to prove this

Let $G$ be a group. We define $H=\{h\in G\mid \forall g\in G: hg=gh\},$ the center of $G$. Prove that $H$ is a (normal) subgroup of $G$.


I made my first node group , now i want the node group to display some fields inside it on the node itself , how do i do that.

I have created a couple of node groups with some "group-inputs-sliders" (The one called "Roughness" in the bottom picture). I would like it to have the blue-bar slider like the blender native ones. Thanks (:


My insert cursor failed in insert any rows.  After spending time trying to fix something within the main loops, I added the del inCursor after the loop and now the cursor inserts rows.  How can something outside and after a loop impact something above?  #------------THIS DIDN'T WORK:     inCursor = arcpy.da.InsertCursor(fcEmpty,["Shape@","NAME","CO_WI", "CO_NRI","A_NUMBER","LSE_NO","ORIG_LENGTH"])     with arcpy.da.SearchCursor(fcPolyline,["Shape@","NAME","ORIG_LENGTH"]) as firstCursor:         for firstRow in firstCursor: # For each feature in input1             inputFeat = firstRow[0]             with arcpy.da.SearchCursor(testingINLAND, ["Shape@","CO_WI", "CO_NRI","A_NUMBER","LSE_NO"]) as intersectCursor:                 for intersectRow in intersectCursor: # for each feature from input2                     # intersect it with the feature from input1                     intersectFeat = intersectRow[0]                     print "check"                     # dimension ==> polygon geometry (where 1 = point, 2 = polyline)                     clippedFeature = intersectFeat.intersect(inputFeat, 2)                     print clippedFeature                     # setup the insert cursor (for the input you previously created)                     inCursor.insertRow([clippedFeature,firstRow[1],intersectRow[1],intersectRow[2],intersectRow[3],intersectRow[4],firstRow[2]]) # Insert the resulting geometry from INTERSECT geometry method     del firstRow, firstCursor     del intersectRow, intersectCursor  #------------THIS DOES WORK:  inCursor = arcpy.da.InsertCursor(fcEmpty,["Shape@","NAME","CO_WI", "CO_NRI","A_NUMBER","LSE_NO","ORIG_LENGTH"]) with arcpy.da.SearchCursor(fcPolyline,["Shape@","NAME","ORIG_LENGTH"]) as firstCursor:     for firstRow in firstCursor: # For each feature in input1         inputFeat = firstRow[0]         with arcpy.da.SearchCursor(testingINLAND, ["Shape@","CO_WI", "CO_NRI","A_NUMBER","LSE_NO"]) as intersectCursor:             for intersectRow in intersectCursor: # for each feature from input2                 # intersect it with the feature from input1                 intersectFeat = intersectRow[0]                 print "check"                 # dimension ==> polygon geometry (where 1 = point, 2 = polyline)                 clippedFeature = intersectFeat.intersect(inputFeat, 2)                 print clippedFeature                 # setup the insert cursor (for the input you previously created)                 inCursor.insertRow([clippedFeature,firstRow[1],intersectRow[1],intersectRow[2],intersectRow[3],intersectRow[4],firstRow[2]]) # Insert the resulting geometry from INTERSECT geometry method del inCursor del firstRow, firstCursor del intersectRow, intersectCursor

I have a script here that takes data from a cross-tabulated non-spatial dataset where monthly values are stored in a single table row for a given year and linearizes those data so that each monthly value is a new record in a new table. I'm using arcpy to create a search cursor to grab the cross-tabulated data and an insert cursor to write the linearized data to a new table. Here is a screenshot of the original table (obviously there are other ancillary fields as well):    The script:  import arcpy, os  months = {'JAN':1,'FEB':2,'MAR':3,'APR':4,'MAY':5,'JUN':6,'JUL':7,'AUG':8,           'SEP':9,'OCT':10,'NOV':11,'DEC':12} ignore = ['Arbitrary_count','TOTAL_MGY','JAN','FEB','MAR','APR','MAY','JUN','JUL','AUG','SEP','OCT','NOV','DEC']  ws = r'D:\Data\Users\jbellino\Project\faswam\data\water_use\SC\FromTomAb\SC_WELLS_data_jcb.mdb' arcpy.env.workspace = ws arcpy.env.overwriteOutput = True tbl = 'ORIGINAL_DHEC_WELL DATA' itbl = 'monthly_dhec_well_data'  fields = arcpy.ListFields(tbl)  rows = arcpy.SearchCursor(os.path.join(ws,tbl)) irows = arcpy.InsertCursor(os.path.join(ws,itbl)) for row in rows:     for month in months:         #--for each row in the original table, and for each month stored in that row,          # create a new record in 'itbl'         irow = irows.newRow()         for field in fields:             if field.name == month:                 #--if the field name refers to a month abbreviation it contains data                 # first convert the month abbreviation to month number                 irow.cn_mo = months[month]                 try:                     # then grab the data in the field and process it into the appropriate                      # fields of the new table in the correct units                     irow.cn_qnty_mo_va = row.getValue(field.name)*1000000                     irow.cn_qnty_mo_va_mega = row.getValue(field.name)                 except:                     #--skip null values                     pass             elif field.name not in ignore:                 #--if the field name is not a month abbreviation, just copy the data                 # to the new table                 irow.setValue(field.name,row.getValue(field.name))         irows.insertRow(irow) del irows   Now, the problem is that the script will process every row in the original table, however not all rows are transferred into the new linearized table. The number of records that do make it is seemingly random and it has happened with a number of different source and destination tables. My work around has been to create/delete my insert cursor inside the for month in months: loop, but this can really bog things down with large datasets. Even then the script always "misses" the last record in the original table and I have to append the monthly values to the new table manually.  Any ideas of what may be going on here?


I'm trying to load data to a combobox and it's working when i run the form without debugging. But when i try to run it with debug mode I get an error :System.InvalidOperationException: 'Cross-thread operation not valid: Control 'ResultBox' accessed from a thread other than the thread it was created on.' How can I fix this? And btw a have a background worker that writes the message when the data is downloaded. I read somewhere that this issue can be fixed using backgroundworker. Here is the form code:  public Form1()     {         InitializeComponent();         backgroundWorker1.WorkerReportsProgress = true;     }      private void Form1_Load(object sender, EventArgs e)     {         backgroundWorker1.RunWorkerAsync();     }      private Task GetDataTask() {         return Task.Factory.StartNew(() => {             List<Result> results = new List<Result>();             results =   GetResults.GetData("http://worldcup.sfg.io/teams/results/");             foreach (var result in results)             {                 ResultBox.Items.Add(result.Fifa_Code);             }         });     }      private void ResultBox_SelectedIndexChanged(object sender, EventArgs e)     {      }      private void SaveTeam_Click(object sender, EventArgs e)     {      }      private async void backgroundWorker1_DoWork(object sender,   DoWorkEventArgs e)     {         await GetDataTask();     }      private void backgroundWorker1_ProgressChanged(object sender,   ProgressChangedEventArgs e)     {         resultsLoadedLabel.Text = (e.ProgressPercentage.ToString() + "%");     }      private void backgroundWorker1_RunWorkerCompleted(object sender,   RunWorkerCompletedEventArgs e)     {         resultsLoadedLabel.Text = "Podaci učitani!";     }   This line of code inside foreach gets the exception :   ResultBox.Items.Add(result.Fifa_Code);   This is the class that gets results:  public class GetResults {      public static List<Result> GetData(string url) {         var client = new RestClient();         var request = new RestRequest(url, Method.GET);         request.AddHeader("User-Agent", "Nothing");         IRestResponse<List<Result>> results = client.Execute<List<Result>>     (request);         return results.Data;     } }

I have a scenario. (Windows Forms, C#, .NET)   There is a main form which hosts some user control. The user control does some heavy data operation, such that if I directly call the UserControl_Load method the UI become nonresponsive for the duration for load method execution. To overcome this I load data on different thread (trying to change existing code as little as I can)   I used a background worker thread which will be loading the data and when done will notify the application that it has done its work.   Now came a real problem. All the UI (main form and its child usercontrols) was created on the primary main thread. In the LOAD method of the usercontrol I'm fetching data based on the values of some control (like textbox) on userControl.    The pseudocode would look like this:  CODE 1  UserContrl1_LoadDataMethod() {     if (textbox1.text == "MyName") // This gives exception     {         //Load data corresponding to "MyName".         //Populate a globale variable List<string> which will be binded to grid at some later stage.     } }   The Exception it gave was     Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on.   To know more about this I did some googling and a suggestion came up like using the following code  CODE 2  UserContrl1_LoadDataMethod() {     if (InvokeRequired) // Line #1     {         this.Invoke(new MethodInvoker(UserContrl1_LoadDataMethod));         return;     }      if (textbox1.text == "MyName") // Now it wont give an exception     {     //Load data correspondin to "MyName"         //Populate a globale variable List<string> which will be binded to grid at some later stage     } }   BUT BUT BUT... it seems I'm back to square one. The Application again  become nonresponsive. It seems to be due to the execution of line #1 if condition. The loading task is again done by the parent thread and not the third that I spawned.  I don't know whether I perceived this right or wrong. I'm new to threading.  How do I resolve this and also what is the effect of execution of Line#1 if block?  The situation is this: I want to load data into a global variable based on the value of a control. I don't want to change the value of a control from the child thread. I'm not going to do it ever from a child thread.   So only accessing the value so that the corresponding data can be fetched from the database.


I found this question and still asking this again since I have clicked 'logout' button properly.(Two times, on top once and then the logout button appeared after this). After all these, I just clicked in the text box for openid, then It showed that I have logged in again. I am using chrome and it was in incognito mode. I cleared the cookies in content settings once.(But I don't see a reason for doing that since the message shows that your local settings will be cleared).   I tried 2 or 3 times and got this. And once I got the error saying this is our fault it is not you message.

When I tried to log out by clicking the logout link at the top (first time for me because I don't really log out of S[OFU] unless I clear my browser's session data), I got the following message:     You're a registered user.      You can log in or out at any time   using the OpenID you've already   associated with your account.   And when I clicked on the parts of the site, it seems that I'm still logged in (see, i'm creating this question after I logged out and this question would probably appear in the list of the questions I asked) and my name is still appearing at the top of the page.  Is this by-design or is this a bug?


Part of the name of the ISO I downloaded was "amd64". Does that mean the ISO is only for AMD computers? Is there an Intel version?

I was told that computers with more than 2 gig's memory need a 64 bit operating system to utilize all RAM.  Is the 64bit Ubuntu download really JUST for AMD processors? I am asking because the disk image I downloaded says AMD64.  So will my new Intel 2.3Ghz Core i3 Dual Core processor work with 64 bit Ubuntu?  It runs the 64bit version of Windows without any qualm.


Based on the question asked   I have few query:   What is the + mean  find . -name "*ABC*" -exec grep -H 'XYZ' {} +   In the above line the last part +, what does it mean? How to find the meaning of any Linux command or syntax which i am not aware of by my own, for example + in the above example. I tried this command man exec but didn't find any help from that documentation.

I find myself constantly looking up the syntax of  find . -name "FILENAME"  -exec rm {} \;   mainly because I don't see how exactly the -exec part works. What is the meaning of the braces, the backslash and the semicolon? Are there other use cases for that syntax?


I can't mount or even boot my windows disk after I installed ubuntu. Can anyone help me, how can I solve this, please?  Error message:  Couldn't analyze partition: Error mounting /dev/sdb1 at /media/mapos/7670A71A70A6DFDB: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sdb1" "/media/mapos/7670A71A70A6DFDB"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sdb1': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the'ro'mount option.

Whenever I boot Ubuntu, I get a message that it cannot mount my windows partition, and I can choose to either wait, skip or manually mount.  When I try to enter my Windows partition through Nautilus I get a message saying that this partition is hibernated and that I need to enter the file system and properly close it, something I have done with no problem so I don't know why this happens.    Here's my partition table, if any more data is needed please let me know.     Device Boot      Start         End      Blocks   Id  System /dev/sda1            2048    20000767     9999360   83  Linux /dev/sda2        20002814   478001151   228999169    5  Extended /dev/sda3   *   478001152   622532607    72265728    7  HPFS/NTFS/exFAT /dev/sda4       622532608   625141759     1304576   82  Linux swap / Solaris /dev/sda5        20002816   478001151   228999168   83  Linux


I need to get the first 10 object from the list that comes from the Query without limiting in the query  notifs = [SELECT id FROM Notification__c                        WHERE Read__c=false ORDER BY Start__c DESC];    like in javascript i can use slice(0, 10),is there any way to get the sublist in APEX?

Sometimes I like to use a Queueable to perform work on a list of Ids or sObjects over the heaver Batchable Interface.   However, to do this, we need a very solid implementation of an Array slice method.  Most other programming languages have a native slice method, but Apex does not.  While I have written my own version of slice and it's working fine, I would be interested in hearing about other implementations of slice - the more efficient the better.  My version is in this Utilities class on github   It's modelled after the Javascript version described on the mozilla site   I would expect that the usage and output be similar to this:  String[] arr = ['zero', 'one', 'two', 'three']; String[] sliced = Utilities.slice(arr,1, 3);  System.debug(arr);      // ['zero', 'one', 'two', 'three'] System.debug(sliced);   // ['one', 'two']


I have to Dell Poweredge 730 systems running 14.04 LTS that will not boot after a security update last night (probably for meltdown). This article on softpedia helped me:  Are more people here affected by this? And why me?  Regards, Nico

Today I got what I presume was the update that should take care of Spectre and Meltdown. That didn't go very well. What do I do now? See screen photo.    I can't boot the 4.4.0-108-generic kernel because of a kernel panic. I'm running 16.04 on an Intel Core i5-4670K CPU @ 3.40GHz × 4.


I would like to store entire url in a variable and insert into a data extension. I know you can grab specific parameters from a url but cant seem to find anything about the entire url with ampscript.   My url looks like this and i want to capture and store the whole thing

I have functionality on a cloud page that depends on the cloud page url. I know how to Requestparameter(), but how do I get the entire url using ampscript or SSJS?


mat = [[0] * 5] * 5 mat[1][1] = 3 print(mat[2][1])  expected output is 0 but compiler is giving 3 Can someone please explain me why this is happening.

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


I have studied for about 250 questions and there are many questions i can't take.. i considered but i don't know how to start... how can i solve this? In second question, there even hint..   Well im so glad if you tell me how to solve

I am trying to figure out how to prove that all rational numbers are either terminating decimal or repeating decimal numerals, but I am having a great difficulty in doing so. Any help will be greatly appreciated.


I have a bookmark: C:\inetpub\services\Full Scan\full scan.url or a link: 10.237.49.250:8080/scanner/run.aspx?FULLSCAN=ON  how can I schedule either of them to open in IE or Chrome?

I'd like to open a website at regular intervals per day, i.e., the browser should open and automatically navigate towards a pre-set URL.  I looked at options like scheduling to open browser, but I can't figure out how to open it with a default URL. (No I do not want to make this my start page)  Any help is appreciated


Does Ubuntu 14.04 have its own 'Task Manager'? Like the one in Windows, where you would check what program is using how much and such.

Is there any task manager for Ubuntu similar to Windows Task Manager?


I know three questions (that gained momentum) that have been posted asking a question which seems the same, but answers to none of them answer the following very well.  Please jump to point 2 & 3 for immediate addressing to the problem.   Knowledge that I currently have: I was introduced to imaginary numbers a while back where just the square root of -1 seemed to be called iota. This made a whole lot of 'things' definable/analyze-able. I have currently studied the two dimensional complex plane, the rotation, Euler form, defining locus/area which is indefinitely better than an algebraic equation/expression, etc. My Question: However, I have failed to grasp that how imaginary numbers even make sense. Let's take an example, let there be a quadratic polynomial not intersecting the x-axis. However, it does with two imaginary numbers. How does it intersect the x-axis when the equation of the quadratic dictates that it doesn't intersect the x-axis (discriminant<0)? My current understanding:Several sites led me to the conclusion that imaginary-axis acts as the 'z' axis and gets the quadratic to intersect with the x-axis somehow. This pushes the curve form a 2-D to a 3-D curve existing in the complex space when we start feeding complex values into the function with the x-axis as the intersection the the two, Cartesian and Complex plane. This 3-D structure now intersects somewhere on the complex plane with the x-axis giving us the complex roots of the quadratic.    I however fail to understand that how this curve transitions from the Cartesian plane to the complex space while being continuous. Does it transform to a surface instead of a curve? If it transforms to a surface then it would have infinite roots with the x-axis(as seen in the video mentioned in the footnote)  I understand that the complex numbers were 'invented' rather than discovered (I'm saying this because other numbers; irrational, rational, negatives actually mean something, hence discovered).  Thank you very much for your valuable time. I really appreciate it.  FOOTNOTE : I have been to the following questions/sites :            This video here is very good    EDIT: The question was marked as a duplicate though it did not in a way adress the same question as the question that was marked as 'original'. I have therefore, changed the title and content to make the question as precise and understandable as possible.

At school, I really struggled to understand the concept of imaginary numbers.  My teacher told us that an imaginary number is a number that has something to do with the square root of $-1$.  When I tried to calculate the square root of $-1$ on my calculator, it gave me an error.  To this day I still do not understand imaginary numbers.  It makes no sense to me at all.  Is there someone here who totally gets it and can explain it?  Why is the concept even useful?


I am trying to draw an oriented regular polygon with TikZ/automata using the following code:  \begin{tikzpicture}[shorten >=0.5pt, node distance=1.2 and 1.5, on grid,auto,>=stealth'] \def \p {10}  \pgfmathsetmacro{\pp}{\p-1} \node[state,accepting] (0) at (2.5,0) {};  \foreach \s in {1,...,\pp} {   \node[state] (\s) at ({360/\p * (\s)}:\R) {}; }  \foreach \s in {1,...,\p} {    \pgfmathsetmacro{\ss}{\s-1}    \path[->] (\ss) edge (\s); } \end{tikzpicture}   After compiling, some the arcs are not departing from the center of the corresponding node. How can I accomplish this? (I tried to add the parameter anchor=center to each node but the result is the same).

As far as I can understand this should draw the same set of five edges in exactly the same way.  The first set of edges are positioned correctly.  But the second set of edges is horribly aligned.  On my screen, of the \foreach edges, the bottom horizontal one is shifted to the right, the others seems to start ok and then end up further from the center of the pentagon then they should.  Aside from wondering how to fix the alignment, I would also love to understand why this only happens inside a \foreach.  I can "solve" this by first drawing the nodes with minimum size=0mm, and then at the very end redrawing them with 2mm, but that seems less than optimal...  \documentclass{beamer}  \usepackage{calc,ifthen} \usepackage{amsthm,amsmath,amssymb} \usepackage{tikz}  \begin{document}  \frame{ \begin{tikzpicture} \def\r{2cm}  \foreach \t in {0,...,4} {   \node[circle,draw, outer sep=0mm, inner sep=0mm, minimum size=2mm] (a\t) at ({90+\t*72}:\r) {} ; }  % draw the edges of the pentagon in a silly way % draws edges from node-center to node-center \draw (a0) edge (a1) ; \draw (a1) edge (a2) ; \draw (a2) edge (a3) ; \draw (a3) edge (a4) ; \draw (a4) edge (a0) ;  % draw the edges of the pentagon in a better way % draws edges from node-something to node-something-else \foreach \t in {0,...,4} {   \pgfmathsetmacro{\s}{mod(\t+1,5)}   \draw (a\t) edge (a\s) ; }  \end{tikzpicture} }  \end{document}


I am beginning to study VAR models, and I have a simple question.   If I have three variables and one of them is nonstationary, can I estimate a standard VAR model? If not, what should I do?

I am currently investigating the impact of certain indicators such as GDP and inflation on the stock market. However some of my variables are non-stationary and some stationary in levels. All variables are stationary in first differences.  My question:   Since I have a mix of I(0) and I(1), I need to take the first difference of the I(1) variables and then use VAR. Say that I have a dependent variable $y$ which is I(0) and independent variables $x_1$ which is I(1) and $x_2$ which is I(0). Do I take the first differences of only $x_1$ and then apply the VAR model? Is that correct?  If I take the first differences, then might I lose the long-run relationship between the variables? Is ARDL the better method in this case?   If you have any references regarding the above I would be grateful.


After updating to 10.8 ‘Mountain Lion’ I’m wondering how I can rebuild everything I have installed through the packaging system Homebrew (similar to MacPorts) to ensure all dependencies are installed optimally for the new system. How can it easily be achieved? The help file offers no hints as to how I can accomplish this.

Context  My employer gave me a MacBook Pro for development work; however, most of the development work I do in my research group is for Linux platforms, and for a host of policy reasons, I can't install virtualization software on this laptop. Homebrew looks like a good way in which to install these tools, especially because it looks very hackable (since it uses Ruby; MacPorts does not look hackable, because it uses Tcl). However, Homebrew relies on system libraries, and for security reasons, my employer may (and from what I hear, frequently will) upgrade my system at any time. I've heard that OS X upgrades will break Homebrew. (See, for instance, ).  Question  How would I go about fixing my Homebrew install after an OS X upgrade? I am fine with deleting it and starting from scratch again, as long as I can do so in an automated way. (For instance, using Puppet plus a Homebrew provider to script a configuration that will automatically build upon running a shell script.) I've been Googling everywhere and can't seem to find any answers to this question.


Within a couple of days I could stand, even make two, three steps.   It is the original sentence. And I have a strong belief that the and is deleted as below.     Within a couple of days I could stand, (and) even make two, three   steps.   "And" is deleted, but I do not know why that is possible. This seems to be a very unusual situation to me, because if "even" was not there, this sentence would just sound off to my ear. What's more, "stand" and "make" are two verbs, not adjectives. So what rule or usage makes it possible to delete "and"?

He called her, emailed her, texted her, tweeted her—all to no use.   Strictly speaking, I would need to write texted her and tweeted her, but I'm omitting and to convey a rhythm and sense of urgency. What do you call this kind of construction, and is it accepted grammar (at least for creative writing, if not in an academic context)?


I have been looking through code for the last 3 days, and the original developer is defining Strings using the String class rather than the string class.  So, when they've used the IsNullOrEmpty method, it's defined String.IsNullOrEmpty.    What I'd like to know is how is the compiler dealing with String.IsNullOrEmpty compared to string.IsNullOrEmpty?    Is there any advantages using String.IsNullOrEmpty over string.IsNullOrEmpty?

Example (note the case):  string s = "Hello world!"; String s = "Hello world!";   What are the guidelines for the use of each? And what are the differences?


I can't upgrade my HTC Desire 616 to KitKat 4.4.4 but my phone is absolutely capable of running this update! How can I update it?

This Community Wiki question is designed to be the "canonical question" for questions asking how to upgrade one's device to a new Android version.   I want to get a newer version of the OS for my Android device. How can I do that?  See also:


Someone marked virtually all my recent questions for new proposals on Area51 as "Not a good example" without any comment -- even some which had already been voted as "On-topic" or "Off-topic". Similar questions by other people were not marked as such.   As I recently had a discussion about a proposal, , where those in favour of the proposal ended up being quite offensive, I think I have grounds to believe that this was someone's "retaliation" towards me with no factual reasons for the bad votes.   Right now, I can't do anything on Area51 because of  (which also made me wonder how to attract the attention of admins, because I've even written mails to area51@SE and team@SE) but generally, I'd like to know if there is any policy regarding such events.   I guess the first thing is to comment on the downvoted questions asking for the downvoter's reason, but as s/he left no comment there in the first place, the chance that they are interested in a discussion seems marginal. Also, of course, I cannot comment right now, because of aforementioned bug. Unjustified downvotes are also bad for the proposals in question, I believe, and of course bad for my rep, which is why I don't just want to let it rest right now.  I'm extremely grateful for any answers and help or ideas on this.    Gosh, it happened AGAIN! Thanks to Pekka, I got enough rep to make a statement in the Fisica discussion -- promptly another downvote on something which is clearly not a bad example, and a rep loss which prevents me from posting comments again. Do I have any chance of finding out who did it?! Anonymity yes please, but I'd at least like to know if there is exactly one person responsible ... and if so, have this monkey banned, for they treat SE sites like 4chan or something. Grrr!    Problem solved by flagging this -- thank you, kind moderator.

I just noticed that I lost a bunch of points from my reputation score, and I used the "reputation" tab on my user profile page to try and track down the cause.  During my investigation, I noticed there was an unusual event of type "reversal". In the normal place of a question title, it says "voting corrected".     What does this mean, and what caused it?  Did I do something wrong? Why did I lose all of that reputation? Is the system punishing me for leaving too many good answers?  Is there any way to earn it back?


How is "/a/./b/../../c/" equal to /c?   I saw this as a question on one of the Stack Exchange sites. Apparently .. means to pop the stack(?). Why is this the case?

Simple question, but I'm not sure where to look and google doesn't respond to periods and slashes.  I'm just trying to count the # of files & directories in the current directory (not including subfolders/files) and was trying to differentiate ls -1 | wc -l and ls | wc -l since they seem identical.  A site I was looking at said "Keep in mind that this is also counting the ./ and ../ directories." regarding the one with ls -1, and I'm not sure if that means it includes the directories before or something (which I don't want), but it didn't seem to do that from testing.  Could someone confirm which one of those would be most adequate for counting # of files & directories in the current directory only (not sub) and what they mean by ./ and ../ directories?


Let $x,y,z$ be positive real numbers such that $xyz=1$. Prove that$$\frac{1}{(x+1)^2+y^2+1}+\frac{1}{(y+1)^2+z^2+1}+\frac{1}{(z+1)^2+x^2+1}\le\frac{1}{2}$$  I cant’t see how any known inequality such as AM-GM or Cauchy-Schwarz can be applied to this, and usually olympiads only require one of those 2.  Suggestions and solutions would be appreciated.  Taken from the 2019 Pan African Maths Olympiad


Error :     TCP Provider: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.**   Things I have worked out so far :   I enabled REMOTE CONNECTIONS on both servers A (SQL Server 2008 R2) and B (SQL Server 2014).Both default SQL Servers(MSSQLSERVER). I turned on both servers and enabled SQL Port 1433 and SQL Browser port UDP 1434. TCP/IP enabled on both servers. I started SQL Browser service on both servers.   But still I am facing above issue. Please help me solve it.

Recently I have developed software using SQL Server 2012. Now when I try to connect, I get this error message:     Cannot connect to AAFI\SQLEXPRESSA network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 – Error Locating Server/Instance Specified)


Well I'm a beginner and I would like to know how to display the array I made(It's an Integer array). I'm just trying to create a simple calculation program that accepts user input on which fighter they would like to pick, and how much money they would like to bet. Again, I'm just a beginner so no hate please.   public class Fighter { private int health; private int attack; private int money;  int[] fighter={health,attack,money};  public Fighter(int h, int a, int m){      health=h;     attack=a;     money=m;  }  public int[] getFighter(){          return fighter; }   }  *******END OF FIGHTER CLASS*****  import java.util.*; public class FighterCreator {  public static void main(String[] args){      Fighter newFighter=new Fighter((int)(Math.random() * 701),                                    (int)(Math.random() * 39), 7000);     System.out.print(newFighter.getFighter()); } }   When I run the code it just displays hexadecimal, can you guys please explain it in a way a beginner would understand, thanks.

In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the  of the array, as defined by Object.toString():  int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(intArray);     // prints something like '[I@3343c8b3'   But usually, we'd actually want something more like [1, 2, 3, 4, 5]. What's the simplest way of doing that? Here are some example inputs and outputs:  // Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5]  // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]


I'm trying to find the title of a book for a patron who has been searching for this book for about 10 years. I believe it's about a middle grade book that she read in the early 2000's and she thought that it was new at the time. Here are the things she remembers:  -There are 5 or 6 stones of power. This particular book is about the red one. (Which might have strength powers but not sure)  -There is a squire with a pet falcon who wants to go on adventures  -There is a gypsy girl that is magical. Her mother is killed and she is searching for her missing brother. Her brother ends up being the assassin that is trying to kill the main characters.  -There is also a boy from our world that fell through a fountain on a school field trip into the magical world while reaching for the red stone.  It is not:   The Deltora Quest  EA Cycle The Seventh Tower series Diadem Westria Sword of Heavens -Worldstone (Stone Duology)

I read this book a few years ago which was part of a series, but I only found the first book and now I've forgotten the name.  The first book featured 3 children/teens from different places that end up on a quest to search for magic gems/stones together and the story takes place in a medieval kind fantasy world. One is a girl, while the other 2 are boys. One of the boys actually finds a stone/gem while he is on a school field trip (I think the gem/stone is red in colour), and when he picks it up, he gets transported to the fantasy land but ends up in some sort of military training ground/camp somewhere in a desert type area.  He isn't familiar with the fantasy world. The other 2 characters each start out on their own on a quest to collect some magical gems/stones which once collected, can be used to fight an evil ruler (I guess).  But halfway through the book, the girl and boy meet up and continue the quest together while the third boy(transported one) doesn't know that the stone he picked up is actually one of the magical stones others are looking for.  A few other details I remember:   The stone the boy finds is red in colour I think  The cover of the book had a border depicting the stones  It's part of a series or trilogy    Some books with similar storylines, but not the one I'm looking for:     Deltora Quest The Seven Towers Sword of Heaven series Westeria series Diadem series


Every way I try to approach this turn it into proving the inequality $|z-w|<|1-\overline{z}w|$. Not sure at all how to approach it at the moment.

Prove if $|z| < 1$ and  $ |w| < 1$, then $|1-zw^*| \neq 0$ and $| {{z-w} \over {1-zw^*}}| < 1$Given that $|1-zw^*|^2 - |z-w|^2 = (1-|z|^2)(1-|w|^2)$I think the first part can be proven by saying $|1-zw^*| = 0$ if and only if $zw^*$ = 1.  And given the conditions that cannot be true. However I don't know if this part is right.


I am doing self-study to learn Data Science (software developer by profession) and needed to read and understand  but this book requires Linear Regression as prerequisite. I  and got good books for Linear Regression and I can order one by Draper and Smit from . This is the only one which I can afford buying, rest all are imported and out of my budget.   I only know Algebra and some Calculus which I learned in last 2 months from MOOCs and Khan Academy and lot of search  but I got no background either in Probability or Statistics.  Can I got straight to learning Linear Regression from the book ?   NOTE: I am not looking to learn Statistics or Math and I do not want to learn any theory either.  I just want to understand Linear Regression so that I can do my Data Science work.

During the first half of 2015 I did the  (by Andrew Ng, GREAT course). And learned the basics of machine learning (linear regression, logistic regression, SVM, Neuronal Networks...)  Also I have been a developer for 10 years, so learning a new programming language would not be a problem.  Lately, I have started learning R in order to implement machine learning algorithms.  However I have realized that if I want to keep learning I will need a more formal knowledge of statistics, currently I have a non-formal knowledge of it, but so limited that, for example, I could not properly determine which of several linear models would be better (normally I tend to use R-square for it, but apparently that is not a very good idea).   So to me it seems pretty obvious that I need to learn the basics of statistics (I studied that in uni but forgot most of it), where should I learn, please note that I don't really need a fully comprehensive course, just something that within a month allows me to know enough so I can get eager and learn more :).  So far I have read about "", any other suggestion?


When you learn about demonstrative pronouns, it seems like a really simple concept. This/these for nearby (physically, or with regards to time), that/those for distant things. Anywhere you go, online language sites, or Youtube, this is where the story ends mostly. But it seems to miss out on the trickier usage of demonstrative pronouns. I can't figure this out:  Here's a sentence:     Next week may change the rest of your life. And I don't say that/this lightly.   What would you pick? This, or that?  I picked "this", and it was incorrect, apparently. "That" seems to be correct, as in:     And I don't say that lightly.   What's the rule here, are we still talking demonstrative pronoun, near/distant?  Same as in this:     Check out this/that Youtube video: (LINK). What do you think of this/that?   The near/distant trick, either in time of physical distance, doesn't really help. Suggestions?  Now,  offers some guidance:     For a concept or idea introduced a few sentences before, I think the   key thing is whether it was introduced by you or the person you're   talking to. If you introduced it, you're "holding" the idea - use   "this". If they introduced it, they're "holding" it - use "that"."   But really, how does it apply here? Do I hold up my previous sentence? I think so – so this should be correct, am I wrong?  Disclaimer: I'm not a native speaker, but my literary agent is (a seasoned writer). He suggested this was incorrect, and that is correct.

Learning and using English I'm always confused about what word to use for referring to things that have been described by me a few sentences earlier: "that" or "this".   Confusion comes from the fact that only the equivalent of "this" is always used in my native language for such referring. But I've noticed that in English for such referring "that" is used as often as "this" (or maybe even more often).  Some examples for illustrating (just tried to google something appropriate to convey my idea better):     We assess local... the demographics of the local population. What are the natural traffic drivers in the area. Things like cinemas and pubs and retail and office and all that type of things and we now put together a bit of a matrix and actually give a weighted score to each of the things we know help our business. That helps us decide in a more scientific fashion.   or:     The problem of Cervantes' origin became after that into a tough matter. Some experts believed that the Cervantes from Alcázar, in the times of the Lepanto Battle, was in the age of a child, more concerned about gathering nests and that type of things than about fighting as a soldier.   and for "this":     I believe lot of people who involved fishery industries in Mexico Gulf are suffering now but as for economic issues, U.S government and other countries will support them and give an utmost response to it. Important thing is that we learn from this mistake and make sure this type of things will never happen in the future and protect nature environment thus we have to take this technology to get energy from water very seriously. I really hope this technology will be available and used for everybody as soon as possible.   Is there a rule describing proper usage of these words in cases like this? (or should I have written "..in cases like that"?)


I tried the process recommended, but was unable to reset the Password. regardless of what I typed, the results were always "root@jimmie-z62FM:~#". I tried adding or deleting spaces and would sometimes get "command not found". I am not going to fiddle with this command input frustration. I am going to reformat and start over from scratch.  I'm new to Linux/Ubuntu (Rank, uninformed Newbie). Installed Ubuntu 12.04 LTS onto old laptop. The installation apparently lifted an old (also, apparently) forgotten password. "password invalid" message with every key combination. I used the installation disc in attempt to get a command line but I get to the "Install (as superuser) Wireless" screen that does not respond to any input. How do I access the proper commands to reset password? I never got the option to burn a recovery disc when I installed.

I'm working on a Ubuntu system, and my client has completely forgotten his administrative password. He doesn't even remember entering one; however it is there.  I've tried the suggestions on the website, and I have been unsuccessful in deleting the password so that I can download applets required for running some files. Is there a solution?


Its been a while I am looking for mechanism of screen capture in MacOS. Even with extensive googling I found no luck with its actual mechanism. Can somebody guide me through some good resources or even better the actual mechanism and implementation of screen capture (with api calls and functioning)? Thanks

Basically I with my team are figuring out a way to block screenshots taken on our corporation's computers (Mac mostly). I have searched it extensively and found that there is something called Screen buffer which is being accessed by any screenshot taking software (eg. Snipping Tool etc). I tried to find the exact mechanism and the actual implementation of such softwares but with no luck. Also I found out that Netflix uses some kind of technology which corrupts screenshot image and blackens it. I did not find any actual mechanism or implementation to study it further. I also came across something called Hardware overlays but did not understand it properly in order to use it for actual implementation. I have considered a way to edit scancode maps in registry but I am looking for a more general way. I read a few articles for apple's FPS though. Can somebody please guide me through this? Some good resources for the same would be highly appreciated. Any particular or relevant forums or subs to discuss this are also welcome


Since updating to 20.04 LTS I've noticed some differences in desktop functionality compared to 18.04 LTS.  Here are a few:   Can't drag and drop a file from the desktop to anywhere else.  Drag and drop from other locations appears to work as before. Can't rename a file using F2, need to right click and use the pop-up menu. Can't open a template on the desktop. I have to create a folder on the desktop and open the template in this new folder. The Del key won't delete a desktop file or folder.  I have to right click and move it to trash via the pop-up menu.   I'll bet there are other differences that I haven't yet come across.  For my style of using the Desktop (keep a clean Desktop, do all current work there, then put things away) these changes degrade the utility of the Desktop.  Are these changes to the desktop intentional or are they bugs that will be fixed.

In Ubuntu 20.04, on the desktop, there is a number of actions I wish I could do, such as, by order of importance :  use keyboard shortcuts such as select all, copy / paste. use drag & drop with icons deactivate the "mouse over" highlight, and restrict the clicking area to only the icon, not the surrounding square  To put it simply, I'd like to have the exact same features as offered by the desktop of Ubuntu 18.04 (probably related to a specific version of GNOME, and not Ubuntu itself). Am I missing something obvious here? I actually see no reason why those actions are removed or deactivated on the desktop, since they all work in any Nautilus window.


I would like to add emblems to a file in Thunar using a script, but I can't find any documentation on this.  Is it possible to do this? And if so, how?  The same question was asked , but they mention a ~/.cache/Thunar/metafile.tdb file which does not exist on my system. I think that question and the answer are outdated.

I'm on Xubuntu 11.10 and currently trying to use emblems in Thunar to mark which videos in a folder I've already watched.  The problem is I can't find any terminal command to do so and neither can I change the properties of multiple files in Thunar as the context menu item 'properties' is greyed out as soon as I select more than one file.  The command 'gvfs-set-attribute' which works with Nautilus doesn't do anything in Thunar. I guess Thunar stores the meta-data in some other way.  Can anyone tell me how to either set the emblems with a custom command (better solution) or change multiple file properties in Thunar?


I compiled the source code and inserted the USB device, according to this blogs instruction:    When I do a lsmod:  lsmod | grep rt rt5370sta              726167  0    However iwconfig gives:  lo        no wireless extensions. eth0      no wireless extensions.   Could someone please tell me what to do so that I can get the USB adapter running fine.

I recently installed saucy as part of a dualboot setup. My laptop's internal network adaptor is shot and so I have to use an external D-Link DWA-123. I have the installation disc and everything and it works perfectly on windows. However, I cannot get it to work on Ubuntu. How can I go about doing so?  My lsusb output:  Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 008 Device 003: ID 0cf3:311d Atheros Communications, Inc. Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 002: ID 0c45:6458 Microdia Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 005 Device 002: ID 0955:7100 NVidia Corp. Notion Ink Adam Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 002: ID 2001:3310 D-Link Corp. Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub


Recently I upgraded to ubuntu 17.10, now whenever I try to launch xampp it gives error:  Initially error was:     Invalid MIT-MAGIC-COOKIE-1 keyError: cannot open display ':0'   After this I ran:     export DISPLAY=desktop:0   Error:     Unknown Error couldn't connect to display "desktop:0"   Later on tried this:     export DISPLAY=0:0    Error:     Unknown Error couldn't connect to display "0:0   NOTE: It is showing single line error as posted above.

I installed Ubuntu 17.10. Now I am having trouble with gksu:  $ gksu -dg synaptic No ask_pass set, using default! xauth: /tmp/libgksu-HgUjgQ/.Xauthority STARTUP_ID: gksu/synaptic/8760-0-alex-XPS-15-9530_TIME4974977 cmd[0]: /usr/bin/sudo cmd[1]: -H cmd[2]: -S cmd[3]: -p cmd[4]: GNOME_SUDO_PASS cmd[5]: -u cmd[6]: root cmd[7]: -- cmd[8]: synaptic buffer: -GNOME_SUDO_PASS- brute force GNOME_SUDO_PASS ended... Yeah, we're in... Unable to init server: Could not connect: Connection refused (synaptic:8767): Gtk-WARNING **: cannot open display: :1 xauth: /tmp/libgksu-HgUjgQ/.Xauthority xauth_env: (null) dir: /tmp/libgksu-HgUjgQ   If I don't use -g, the password dialog is disabled. So looks like a problem with creating a tty for root.  Any advice?


Why always my Kubuntu non detect my 3G/4G Card? Always, when I turn on my computer, I need to do this steps to turn on the 3G/4G Integrated card mu736 huawei - model [  The steps that I need to follow in the Konsole are:  ALL ALL= NOPASSWD: /home/victorsnk modprobe option echo "03f0 521d" > /sys/bus/usb-serial/drivers/option1/new_id usb_modeswitch -H -v 03f0 -p 521d -s 10   the result thrown is:  victorsnk@victorsnk-HP:~$ sudo su [sudo] password for victorsnk:  root@victorsnk-HP:/home/victorsnk# cd script root@victorsnk-HP:/home/victorsnk/script# ./modem.sh ./modem.sh: línea 3: ALL: orden no encontrada Note: No target parameter given; success check limited Look for default devices ...    product ID matched  Found devices in default mode (1) Access device 002 on bus 002 Current configuration number is 1 Use interface number 0  USB description data (for identification) ------------------------- Manufacturer: Hewlett-Packard      Product: HP hs3110 HSPA+ Mobile Broadband Device   Serial No.: not provided ------------------------- Send old Huawei control message ...  Check for mode switch (max. 10 times, once per second) ...  Wait for original device to vanish ...  Original device can't be accessed anymore. Good.  (For a better success check provide target IDs or class)  Original device vanished after switching  Mode switch most likely succeeded. Bye!   *Note: I had to created a script to resume the process, but I can't get start it at the ini when I start the computer. Anybody knows how can I solve it?  My OS is Kubuntu 16.4 LTS (64x) and my kernel 4.14.0-041400-generic  Thanks!

I have a Huawei 3G module, model MU736, installed by default on my Clevo laptop, Ubuntu 14.04 64.  Here is what I know:   I have a dual boot with Debian 8 Jessie (which despite of Ubuntu doesn't work with nvidia drivers) and this one works almost properly with the modem (after doing dpkg-reconfigure modem manager) , maybe I can use it to know how it works. The module is fully supported by free desktop modem manager, as listed here:  Usb modeswitch works properly as I can see the modem interface in lsusb and even the modem serial port in /dev/ttyUSB1 and I den see it in modem manager GUI but with no access. I tried dpkg-reconfigure modemmanager with no luck, even purge and reinstall didn't work.   Help!


How can I define a variable, which is calculated from different variables, something like this: \newcommand \varA {3} \newcommand \varB {2} \newcommand \varC {\varB*\varA}  So that \varC will conain 6 and not 3*2. This is important, since \varC will be used as a variable in text and in a pgfplot.

Please, what I'm doing wrong in this test:  \documentclass{article}   \usepackage{tikz}   \begin{document} \begin{tikzpicture}  \pgfmathparse{10*2} \node at (4,-5) {$2 \cdot 10 = \pgfmathresult$};  \end{tikzpicture} \end{document}   It gives as output a line:  2 * 10 = -5.0   instead of:  2 * 10 = 20   ?


Summary: Is there a more elegant solution to the code block below? Details: I send an HTTP request to a server with WebRequest. The server might respond with 404 or another HTTP error code. It seems that the only way to handle these HTTP error codes is using try-catch, as in my code below. I thought error handling like this should only be for 'proper' errors, whereas I consider the HTTP error codes to be legitimate responses. For example, I'd (a) like to do a Select Case on myWebResponse.StatusCode (which might be 200, 202, 404, or something else), and (b) I don't want to have to explicitly re-throw or handle other WebExceptions that might occur; those should just go to whatever error handling happens to be in place at a higher level. My solution works, but would be neater if I could replace the whole block below with something like myWebResponse=myWebRequest.GetResponse(AcceptHttpErrorStatuses:=True). Is something like this possible, or does everyone use similar try-catch solutions? I suppose I should write a function that does the try-catch. Do others agree that the try-catch approach is ugly, or do you think exception handling is always appropriate for HTTP error codes? Try     myWebResponse= myWebRequest.GetResponse() Catch ex As WebException     If Not ex.Response Is Nothing Then         myWebResponse = ex.Response 'So that I can later do Select Case myWebResponse.StatusCode.     Else         Throw 'To re-throw proper exceptions like Timeout     End If End Try

I am in a situation where when I get an HTTP 400 code from the server, it is a completely legal way of the server telling me what was wrong with my request (using a message in the HTTP response content)  However, the .NET HttpWebRequest raises an exception when the status code is 400.   How do I handle this? For me a 400 is completely legal, and rather helpful. The HTTP content has some important information but the exception throws me off my path.


I'm required to change my school Gmail password every year.  I recently did so, and it seems to work just fine for accessing Gmail with a web browser.  It also works fine in the Mail app in iOS (I was asked to enter the new password, but it accepted it just fine).  However, in the Mail app on macOS, I've run into some issues.  It shows a "Login Failed" message on the top right of the window as well as the telltale lightning bolt "offline" icon to the right of the mail in the left sidebar.  I totally expected to see both of those, since Mail is trying to access the account using the old password.  But I can't get past that.  If I click on either of those, it opens a dropdown/popup where I can enter the password:   That's all good.  After I enter the password, though, I see a "loading" animation (a spinning-type one) for a brief second and then just blank gray in the window:   The same thing happens if I try to do this in the Internet Accounts section of System Preferences.  Does anyone know why this is happening and how I can resolve it?

I am trying to add a Google account using System Preferences > Internet Accounts.  I already tried the following.   able to reproduce this in 10.12.3 and 10.12.2.  disabled OTP, same issue able to reproduce in Macbook Air and Macbook Pro same issue with both Gmail account (tried two) and Google Apps account I am not using any iCloud it appears to be similar to this issue but the fix does not work:  adding LinkedIn works I already tried to VPN to California and Singapore to check if something is wrong with Google mirrors creating a new user account and adding the Google account from there, same issue as advised by Apple Support tried    It gets stuck right after a successful login. I took a screenshot.    Anybody experiencing the same issue?


My plan is to achieve analog video effects like RGB channel desynchronisation.   I'd like to have something like this (I hope you get the idea):  Left: White dot; Right: The same dot, but mind the channel offsets (the center should be brighter and white).

How would you implement the effect of  with shaders?  Would rendering of the world with different focus distances for each color solve the problem (maybe with the usage of only one depth rendering pass)?


I have a module and created twig templates there. I just followed the documentation here:   I want to include a JS file from the twig. And the JS file is located inside the module folder. I have this code in the twig:  <script src="/{{ directory }}/js/script.js"></script>   But the directory is returning the theme path NOT the module path. How can I get the module path inside the twig?

I'm creating a module in Drupal 8 and I need to define a relative path to mymodule to pass it on a JavaScript file like this.  $scope.getPlatformIcon = function (_platform) {      var modulePath = "/modules/mymodule"      switch (_platform) {          case "youtube":          case "twitter":          case "instagram":          case "facebook":              return modulePath+"/img/"+_platform+".png";      }      return false; };   In Drupal 7 I could use the following.  var modulePath = Drupal.settings.mymodule.basePath;   For the Drupal 8 root directory, I could use the following.  drupalSettings.path.baseUrl   I didn't find how to get the module path.  How can I do it with Drupal 8?


So i have the following subspace  r − s − 2t − u  −r + 2s + 5t + 2u  s + 3t + u  3r + s + 5u  $$\begin{bmatrix}1 & -1 & -2 & -1 \\  -1 & 2 & 5 & 2 \\  0 & 1 & 3 & 1 \\  3 & 1 & 0 & 5 \\  \end{bmatrix}$$ These four equations are all put into square brackets. There are no zero's in the questions equal to the equations. This is a past exam question .   And i need to find the basis. I know that r,s,t,u are all scalars. I was thinking of decomposing these equations into variables and numbers, but i am not sure.  How would i find the basis ? Could somebody help me ? I was thinkig it might have something to do with the span.  YES i already asked the question. Please to not mark it as a duplicate.. I asked it again so more people can see it and maybe help me.

So I have the following subspace  $r − s − 2t − u=0$  $−r + 2s + 5t + 2u=0$  $s + 3t + u=0$  $3r + s + 5u=0$  And I need to find the basis. I know that  $r,s,t,u$ are all scalars. I was thinking of decomposing these equations into variables and numbers, but i am not sure.  How would i find the basis ? Could somebody help me?  I was thinkig it might have something to do with the span.


My Combinatorics notes mention the theorem Orthogonality of Binomial Coefficients which states: $$\sum_0^n{{n \choose k}{(-1)}^kp(k)} = 0$$ where $n \in \mathbb{N}$ and $p(k) \in \mathbb{R}_{n-1}[k]$ The proof given is to differentiate $$(1-t)^n = \sum_0^n{{n \choose k}{(-1)}^kt^k}$$ $r$ times, where $r<n$ and then evaluate at $t=1$, which is where I get stuck, since all terms in the sum where $k\geq r$, the inside of the sum is $\frac{k!}{(k-r)!}$ inside the sum, while for $k<r$, the $t^k$ term becomes $0$, so I'm left with $$0 = \sum_r^n{{n \choose k}{(-1)}^k\frac{k!}{(k-r)!}}$$ which would be enough to finish the proof if the sum indices ran from $0$ as I could just use linear combinations of this sum with different values of $r$ to get any polynomial of degree at most n-1 What I want to know is how am I meant to take this derivative to keep the sum index from $0$ to $n$, or is there another step after having taken the derivative to show the equality is true for all $n-1$ degree polynomials?

Could somebody explain to me where these two formulas come from as applications of the binomial theorem?  $$\sum_{k=0}^n {n \choose k}(-1)^kk^r=0$$ for non-negative integers $r\lt n$. And $$\sum_{k=0}^n {n \choose k}(-1)^kk^n=(-1)^nn!$$


I was looking into a couple of exercises: First exercise:  Prove that if $x \mid (x^2 + 1)$ the $x = 1$ or $x = -1$  My solution was that if $x \mid (x^2 + 1)$ this means that $x | x^2$ and $x | 1$. The only number that is a divisor of $1$ is 1/-1. Hence $x = 1$ or $x = -1$ Second exercise:  Prove that if $6 \mid (x^3 - x)$ for every integer $x$ (hint among $3$ consecutive integers, one must be a multiple of $3$  Now for the second exercise I started with the same approach i.e. that if $6 \mid (x^3 - x)$ then $6 \mid x^3$ and $6 \mid x$ and then I realized that the question is about to prove that it holds for all integers which is not obvious to me that it does. So I plugged in some value e.g. for $x = 7$ we have $7^3 - 7 = 343 - 7 = 336$ which is a multiple of $6$. Also for $x = 5$ we have $5^3 - 5 = 125 - 5 = 120$ again is multiple of $6$. So the $6 \mid (x^3 - x)$ seems to hold but I notice that for $x = 7$ we indeed have $6 \mid (7^3 - 7)$ but it is not the case that $6 \mid 7$. So I have two questions here: a) Is it wrong to consider that if $x | (a + b)$ then $x | a$ and $x | b$? Or are there specific conditions that this formula holds? Does that mean that my solution to the first exercise is wrong? b) how can I use the hint to solve the exercise? It is not clear to me

I read the following two sources and I think I understand the structure of proofs involving WOP, but I am stuck on the open-ended part where you prove P(n-1) for the  following problem:    Use the well-ordering principle to show that n^3 - n is divisible by 6.    Any help would be greatly appreciated!   Note: After factoring out (n-1)^3 - (n-1) it took the form of n^3 - 3n^2 + 2n and the only difference between that and n^3 - n is "3n^2 - 3n" which I proved was divisible by 6 via induction. Is there a better way to solve this problem?  Edit: , post is useful however I not supposed to use induction for the main part of the proof.


Show that if $a$ and $b$ are positive integers then $(a!)^b b! \mid (ab)! $    This is what I have done:   The above statement is true for $a=1$ and any arbitrary value of $b$, and also for $b=1$ and any arbitrary value of $a$. Now for $a \ge 2 $ and $ b\ge 2$, $a+b\le ab $. This implies, $ (a+b)!\mid (ab)!$ and since $$\dbinom{a+b}{a} = \frac{(a+b)!}{a!b!} \implies a!b!\mid (a+b)! \implies (a!b!)\mid(ab)!$$        Any ideas how to further progress in this proof? Or are there any other ways to prove this?

Let $m$ be a positive integer and $n$ a nonnegative integer. Prove that $$(n!)\cdot(m!)^n|(mn)!$$  I can prove it using , but I have to use the lemma that $$ \dfrac{\displaystyle\left(\sum_{i=1}^na_i\right)!}{\displaystyle\prod_{i=1}^na_i!} \in \mathbb{N} $$ I believe that it can be proved using the lemma, since  he has mentioned so at the end of his answer. Any help will be appreciated. Thanks.


in Fluid mechanics? Yes, this is my question which one should i use in fluid mechanics most, and why, which one is more practical?

I'm having trouble understanding the motivation between wanting to transition between the two descriptions.  I figure that switching from  is useful if we want to recover a particle's trajectory maybe? Is there any other reason to do so? and then what are we measuring by switching from Lagrangian to Eulerian?