We know that the curvature of spacetime is gravity itself and it is not a force.so,why do we feel our weight in a curve spacetime but not in a straight(I mean not curve) space time like zero gravity space?Why something called "Curvature" produce weight we feel?

I understand that people explain (in layman's terms at least) that the presence of mass "warps" space-time geometry, and this causes gravity. I have also of course heard the analogy of a blanket or trampoline bending under an object, which causes other objects to come together, but I always thought this was a hopelessly circular explanation because the blanket only bends because of "real" gravity pulling the object down and then pulling the other objects down the sloped blanket. In other words, to me, it seems that curved space wouldn't have any actual effect on objects unless there's already another force present.   So how is curved space-time itself actually capable of exerting a force (without some source of a fourth-dimensional force)?  I apologize for my ignorance in advance, and a purely mathematical explanation will probably go over my head, but if it's required I'll do my best to understand.


I've just found my access card to the suggested edits review queue, and find that there are a lot of low-rep retag edits in the queue thanks to this:   Now, as far as I understand, a retag is intended to only change the tags and as such at first glance will always seem a minor edit, but unless it is an outrageous suggestion, it is still a worthy edit and should be approved. However, I have noticed that most retag suggestions have at least one reject flags on it.  What is the right approach here? I have tended to approve most retag edits if they, like I said, were actually related to the question.

Say, there's a Java (C#, Javascript, etc) question involving array and tagged only 'java'. Two months ago nobody would lift a finger to add 'arrays' tag: the benefit is tiny, if it exists at all.  Yet, last few days I've been noticing a lot of such edits and not sure what to do. Some users even go on retagging rampage, updating every question they can lay their hands on (you can see them repeatedly in the list of pending edits).  I don't mind those guys getting their lousy 1000 reputation this way (well, only a little), but somehow I feel that the system was intended for slightly more substantial changes.    What would you do in this case? Approve or reject?  PS Some examples from the last few minutes


How can you tell what version of Minecraft you have? I have tried looking in the app store and it doesn't show me the version I have.

I don't know which version of Minecraft I have. I have regular Minecraft, not Java or anything else and I just don't know the version I have.


From what I understand the 'nouveau' driver does not support CUDA. I compiled a very simple CUDA program and was very surprised that it did actually run successfully. Is there now some CUDA support in the 'nouveau' driver?  Edit: What I did was building a simple CUDA program that allocates and initializes a number of arrays of floating point numbers, launches a saxpy kernel and compares the result. In fact the program ran fine (main returned 0) which had me concluded that also all other part of the program ran fine. Since I'm running the nouveau driver I further concluded that some CUDA support is available. What I did not pay attention to was the fact that the program's result was actually wrong. It looks like the program didn't launch the compute kernel but did everything else. I didn't consider this a possibility.  This is Ubuntu Desktop 20.04 with GFX1070 on Intel based PC.

I have installed Ubuntu on, but now I am trying to install NVIDIA CUDA Toolkit for the GPU. When I install it, it says that there is no driver found, so I have tried to install the driver, but I don't know why after installation, the system not coming up. Maybe it is because of the wrong version of the driver.   When I tried to detect the driver version using sudo lshw -C display , it showed this information:    But here it doesn't say that what is the product name of the driver, and also when I go Software & Updates -> Additional Drivers, then it says NVIDIA Corporation: Unknown.    What should I do?


Having just recently reached 2K rep and edit review capabilities I've noticed that suggested edits are typically approved/rejected in less than 10 seconds. If you take your time to read the suggested edit, you will almost certainly have it approved or rejected out from under you.  Is this intentional?   It seems to be impacting the quality of the review process.  If this is not intentional, I'd like to request a fix:   Parcel the suggested edits out to fewer reviewers, or  Lock the ability to approve/reject to the first reviewer for a short time (~ a minute?) to give enough time to carefully review the suggested edit

Already I have lost all hope of looking at late answers etc. It's just a parade of meh. I can't make any kind of intelligent decision because I can't see the other answers to the question, for instance. There's no Looks Good, only Skip, and those feel different to me. So I've been more interested in .  But people keep approving crap while I'm looking at it. Two or three "the post was already approved; please visit to edit" and I'm just "screw this whole thing".  Can we do something like one reject bounces all existing votes: you need three approves in a row? Because a lot of people are stupidly approving and actually driving me away from the queue.    Note this is less about letting bad edits through and more about keeping reviewers motivated.


I was wondering which is the fastest for general use. So instead of push_back() we could use the following code for arrays. I thought arrays are faster but I am not sure of that.    int *p;  p = new int[5];  for(int i=0;i<5;i++)     *(p+i)=i;   // realloc  int* temp = new int[6];  std::copy(p, p + 5, temp);   delete [] p;  p = temp;

In our C++ course they suggest not to use C++ arrays on new projects anymore. As far as I know Stroustroup himself suggests not to use arrays. But are there significant performance differences?


I installed Ubuntu 13.10 in my PC recently, also installed Eclipse, Qt Creator, Blender and Synaptic (to download all the packages in order to work with OpenCV) everything went fine until i shut down the computer and then later, when i tried to log in Ubuntu, put my password an everything, the screen went black, and only the pointer appeared.. Tried several things to fix it but nothing work so i re-installed Ubuntu, and all the programs again but testing re-starting the computer after every installation, and all of them work except for the OpenCV packages, after installing them the blackscreen problem came back.  If anyone can help me please i'll appreciated a lot

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:


I need to prove in a Combinatoric way that: $$\frac {(2n)!}{n! 2^n}$$ is an integer for all natural $n$. Actually I have no idea where to start from. Thank all.

I came across this expression :   $ \frac {(2n)!} {2^n n!} $   I know that this evaluates to an odd integer. More specifically :  $ \frac {(2n)!} {2^n n!} = (2n -1) \cdot (2n - 3)\cdots 5\cdot3\cdot1$   I want to know where this expression comes in a real-life scenario. For example $\sum_{k=0}^{n}{n\choose k}$ represents the number of ways to choose a subset from a set of cardinality $n$.


Is it a good idea to expire passwords after a time relative to their complexity? Is it a good way to teach users to use secure passwords? ()  I'm thinking of giving hints on how to make the password stronger, and displaying the expiration date of the new password while the user is typing it.  EDIT: There seems to be a lot of answers pointing out that storing the relative difficulty of passwords (or something that hints of it) is insecure. That is true for most systems used today, but it doesn't have to be. If the passwords expire in 1/1000 the time it would take all computers on earth to crack it, it would still be fairly secure. The point of a variable expiration would be to allow less secure passwords, rather than forcing everyone to use one that will be secure until the heat death of the universe. Switching passwords every few years, while being allowed to use a 10-20 character shorter password, is probably a good tradeoff for many people.   It turns out that this security concern isn't even the real issue, as the great people over at . From a security perspective, expiring passwords are used to limit the time a compromised password (e.g. from shoulder surfing) can be used. As they point out, if you have access to the hashes, and thus the ability to attack them locally to avoid any rate limiting set up on the site, you probably have enough access to the system to do whatever you want anyway.

I have a dispute with my partner. He comes from a financial software background but I do not. He recommends that our web app should expire user's passwords after 6 months (and it has to be unique each time). However, our target audience will be in construction. I think it will annoy the users and not provide enough security to justify the annoyance.  Do you think passwords should expire?


I am attempting to make an Abelian Sandpile Model (see: ) in Python 3.8, and I have not looked at the provided solution because this is a practice exercise for me. I am getting started with a possible solution, but I am not sure why the following issue is occurring.  I have a 5x5 grid, composed of lists.   # a list composed of 5 child-lists, each containing five 0's area = [[0]*5]*5   My first step is to place the sandpile (ie. change one (x, y) pair to a higher number), and I have written this function to accomplish that:  # changes one location to a greater height, takes a one-based (x, y) pair def make_sandpile(area, loc, height):      # accommodate for zero-based counting     loc = list(n-1 for n in loc)      # translate to x and y     x, y = loc      # change the corresponding point in the area     area[y][x] = height   calling make_sandpile(area, (3, 3), 4) should have the following outcome:  0 0 0 0 0          0 0 0 0 0 0 0 0 0 0          0 0 0 0 0 0 0 0 0 0    ->    0 0 4 0 0 0 0 0 0 0          0 0 0 0 0 0 0 0 0 0          0 0 0 0 0   However, the outcome is as follows:  0 0 0 0 0          0 0 4 0 0 0 0 0 0 0          0 0 4 0 0 0 0 0 0 0    ->    0 0 4 0 0 0 0 0 0 0          0 0 4 0 0 0 0 0 0 0          0 0 4 0 0   What can I do to correct this?

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?


Due to extended exposure to wide SE network, hot questions tend to attract certain amount of low quality answers   . These answers would better be (and eventually are) removed, but on smaller / subjective-ish sites removal takes quite a lot of time due to . This slowdown in removal, coupled with the way how  depending on amount of answers causes hot questions stick in the list longer than it would be in case of timely removal. Suggest to  to account for amount of answers. This would unblock other  /  questions of the site and allow them to enter .  ##Diluting the brand No matter what their purpose  is, it isn't reasonable to ignore long-term educational impact hot questions make on  audience. Current approach suppresses questions having less answers - given limited capacity of the hot list, this is just another way to say that it indiscriminately favors questions having more answers. This sends strong signal to SE users on what kind content is welcome here. You may write and refer blog posts about  until hell freezes over, but everyday reality of seeing other kind filling the sidebar works totally against the idea of welcoming laser sharp questions having "single correct answer", no matter how you try. As observed in another discussion of related matters, this :  watching the 'hot network questions' leads me to think that several of the recent sites are gigantic broken windows of self-absorbed subjectivity... The questions are whiney, the answers are opinion, and the voting ... oh the voting.  I try to resist the 'reality TV' temptation to click on hot questions on these sites, but every so often I fail... For the sake of completeness, brand dilution may be less visible from outside of Stack Exchange, as web searches eventually correct artificially promoted  stuff and bring truly valuable / entertaining  content back to top, fixing the issue for visitors coming here from web searches. It's SE regulars, active askers and answerers, who take the hit of fake popularity conditioning coming from sidebar, it's them who get a long standing impression that asking questions to gain as much answers as possible is the way to go. ##"Protection" that makes a room for damage The very  that prevents list from being dominated by Stack Overflow, makes room for it to be dominated by questions from sites less capable of moderating highly exposed content. Think of SO regulars (making probably the largest audience of the hot list), what do they learn from it? No matter how good are SO questions that get into the list, vast majority of what is promoted there is not like that.  Yeah average SO user can't see SO questions that fail to get to the list but what they see instead are mostly questions from other sites, encouraging multiple answers. This teaches list audience that it's a norm, that system encourages that. They think wow this works so well at other site(s), let me try something similar at SO. Yeah their attempt will most likely fail  and their question will likely be voted down and closed, but, alas, this won't help next guy seeing the same skewed selection at the hot list.  No matter how you close, downvote, educate those who tries it at Stack Overflow, this won't stop new users from trying weird "hot-like questions" again and again and again - simply because that's the way promoted to them from the hot list - every day, day by day, week by week, month by month.

Right now there are multiple questions that have been on the Hot Network Questions list for a large number of days:   8 days -  8 days -  7 days -  5 days -  5 days -    There are also seven that have been there for four days.  I do not see what value a question sitting on the HNQ has when it is there over a week. They clog the HNQ and make it harder for other questions to get there, lowering overall exposure to other sites. They also disproportionately give reputation to users on those sites who have answers there, which results in a dilution of the meaning of reputation.  It is also not uncommon for questions to stay there this long.  My recommendation is a simple change to add a hard cutoff that when a question is more than 72 hours (3 days) old, it no longer is present in the HNQ list.  This would be as simple as adding a date filter into the query generating the list - the hotness formula itself doesn't need to change in order to effect this result.  The goal of this suggestion is not any of the following:   Comprehensively fixing HNQ (there are other problems with it) Revamping the calculation  Imposing site limits/etc   It is purely to add a basic and simple filter to the query in order to more quickly cycle questions through the list.    Note:


I have my Ubuntu Software Center set up to display available snaps. Some apps have both a snap version and an Ubuntu Software Center version available. However, I don't know what the difference is between them. I've seen rumors that snaps are self-updating, but I don't know if Ubuntu Software Center apps can do that, too. In general, I'm wondering what the differences and pros/cons are between the two.

This is not a duplicate of the following questions     because:  My question specifically states that I am interested in end-user experience, not ease or efficiency of development, which is what the other question largely refers to.  As has been noted, development/deployment affects end-user experience, but it is not all there is to it, and neither of the referenced questions address issues that directly impact an end-user's ability to use the application (e.g. trouble accessing data on other partitions, sluggishness, etc.) Maybe "compelling" wasn't the right word to use; my intent was to ask about real-world, experiential consequences, i.e., things that happen or  don't happen, as opposed to theoretical/architectural statements that, while presumably accurate, don't appear to be backed up with any real-world examples to support the statement. I should have stated more directly that my intention was to get answers that consider the balance of "advantages" to snaps against the real-world downsides experienced by end-users. The "duplicate" question is largely theoretical, and doesn't discuss end-user experience at all. The "duplicate" question makes no mention of anything remotely similar to the example I used here, i.e., that there is an end-user downside to snaps (in this case, lack of access to data on other partitions and snap app performance) that isn't discussed in any available documentation that I can find.   While I understand that snap has a big advantage in making apps more widely available, is there any compelling reason to choose snap over apt, if the app is available for my distro/version via an apt package? I am curious because I've been doing some reading about snaps, and all the excitement about the method seems to be about things that are advantageous for app developers, but I've seen virtually nothing on how this makes life easier for end users (aside from the obvious; that they may be able to install apps that aren't otherwise available on their distro/version). I installed snapd and installed a couple of snaps and was really frustrated and disappointed.  The snap apps are slow and it's difficult, if not impossible, to access files on other partitions from within the snap. While I've seen plenty of info that says snaps are "faster," "easier," "safer," etc., I haven't been able to find anything that explains why or how this is actually the case. Being very new to Linux, I am wondering if maybe I'm just missing something obvious? To be clear, I understand why the technology might be useful overall, but I can't find anything that explains whether/why it is a better option even when the app in question is available for install via a more traditional method, and all dependencies are met.


I have visited over 30 different forum questions about this very same issue but none of them have been able to point me in the right direction.  I don't care what is causing the issue. I don't care what the error messages say.  I want to completely disable this from happening.  I don't want to disable all logging on my system just this .xsession-errors file.  I have tried the /dev/null thing it doesn't work. I made it read-only, just creates a new file .xsession-errors.jkhbjhjh. I even commented out the file generation in /etc/X11/xsession.  I'm running an ecommerce webserver that will be decommissioned in less than 90 days. I just need to keep the sites up long enough to get them all moved over to my new system. This log file is filling up my HDD 2 to 3 times a week rendering my webstores inoperable.  Just to be clear, I'd like to know how to disable .xsession-errors logging. I'm running Ubuntu 9.10 with gnome. I know it's no longer supported but again, this server is being decommissioned in less than 90 days it shouldn't matter.

Is there any way to completely disable the .xsession-errors file?  I have it as a symlink to /tmp so that my laptop hard disk can (hopefully) go to sleep for once, but at least 95% of the stuff in the file (it fills up at about 500k an hour) is...  (nautilus:1618): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed  which is total garbage to me.  I have tried doing a symlink to /dev/null but that does not work (the resulting link is overwritten), and I also do not want the activity so that hopefully my laptop can go to sleep for once.  I am using Ubuntu 11.04, with no special add-ons to Nautilus.


I have a mail server with Postifx (and dovecot) setup, on which there is an alias address (say alias@example.com) which forwards mail to my main email (myname@gmail.com). This works fine, and all mail I send to alias@example.com gets sent to myname@gmail.com  However, when I reply to an email sent to alias@example.com (using the gmail web interface), to the recipient, it looks like the mail came from myname@gmail.com (or more specifically, the user of myname@gmail.com, eg. Joe Bloggs).  Is there a way to make the email look like it came from alias@example.com, or even just a custom name (such as Alias) rather than coming from Joe Bloggs < myname@gmail.com >?

I have a domain registered, but it isn't attached to a hosting package or e-mail account. I will do soon, but not at the moment. Right now, I would like to set up an e-mail forwarding scenario. So, I could have the email me@example.com forward to my@gmail.com. I know this much is possible.  I would like the Gmail account to keep the forwarded e-mail address when replying. So when I reply to emails sent to Gmail through my e-mail forwarding, I would like any reply to say it came from me@example.com instead of my@gmail.com.  How would I go about it?


I cannot seem to find why I am getting this error message. I thought I have already instantiated my array in my main.  Exception in thread "main" java.lang.NullPointerException  public class A1ArrayList<E> {     private E[] e;     private int capacity = 0;      public A1ArrayList(){     }      public int size(){         return e.length;     }       public boolean add(E addElement){         e[capacity] = addElement;          capacity = capacity + 1;          return true;     }      public static void main(String[] arg){         A1ArrayList<Object> e = new A1ArrayList<Object>();          e.size();      }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I'm learning illustrator today and when I start to justify a text. some words (F a c i l i si) start to stretch too far away. is there any option so I can fix this?

I want my text to produce exact outcome of 'justify all lines'. i took text, dragged it, created a box (exactly the size i want my paragraph to be in) and then applied 'justify all lines' from paragraph option.  but it creates huge gap/space between words (look at disease and management). and it destroys all aesthetic vibe. if i delete the space my letter gets deleted too. and if i modify the box size it is still not removing all those unnecessary spaces.   what i need to do to get 'justify all lines' result?


During Itachi Nagato vs Naruto in episode 298. We have seen Itachi's decision been changed by kotoamatsukami. Kabuto also noticed this. Why didnt he just closed his reanimation and close him in the wooden closet?

I know that the Kotoamatsukami rendered Itachi free of Kabuto's control over his will. But he was still bound to the Edo Tensei, since he was released when the technique was cancelled.  So, couldn't Kabuto simply have un-summoned Itachi?    We have, in other situations (namely in chapter 514, with Deidara), seen that Kabuto can un-summon shinobi at will, an empty coffin appearing and 'reclaiming' the summoned. Were these other situations somewhat different from the situations with Itachi? Or did Kabuto have to completely undo the technique, even if he just wanted to un-summon a single shinobi?


I have created one progress-bar for my web page. I need to stop it, Here is my script for the progress-bar, how I can stop progress-bar before time complete   var elem = document.getElementById("progress-bar"); var width = 1; var id = {};  function progressBar1() {   function frame() {     if (width >= 100) {       clearInterval(id);     } else {       width++;       elem.style.width = width + "%";     }   }   id = setInterval(frame, 160); }       #progress-bar {         height: 10px;         width: 0;         background-color: #000;         position: relative;         transition: linear;       }

     <button id="start" onclick="progressBar1()">Start</button>     <button id="stop">Stop</button>     <button id="reset">Reset</button>

I am using setInterval(fname, 10000); to call a function every 10 seconds in JavaScript. Is it possible to stop calling it on some event?   I want the user to be able to stop the repeated refresh of data.


Show that the metric $d_1$ on $C([0,1])$ does not give rise to a complete metric space.  $$ d_1(f,g) = \int_0^1 |f(s)−g(s)| \, ds $$

I am completely stuck on this problem: $C[0,1] = \{f: f\text{ is continuous function on } [0,1] \}$ with metric $d_1$ defined as follows:  $d_1(f,g) = \int_{0}^{1} |f(x) - g(x)|dx $.  Let the sequence $\{f_n\}_{n =1}^{\infty}\subseteq C[0,1]$ be defined as follows:  $    f_n(x) = \left\{    \begin{array}{l l}      -1 & \quad \text{ $x\in [0, 1/2 - 1/n]$}\\      n(x - 1/2) & \quad \text{$x\in [1/2 - 1/n, 1/2 +1/n]$}\\   1 & \quad \text{ $x\in [1/2 +1/n, 1]$}\\    \end{array} \right.  $  Then $f_{n}$ is cauchy in $(C[0,1], d_1)$ but not convergent in $d_1$.  I have proved that $f_{n}$ is not convergent in $(C[0,1])$ since it is converging to discontinuous function given as follows:  $    f_n(x) = \left\{    \begin{array}{l l}      -1 & \quad \text{ $x\in [0, 1/2 )$}\\      0 & \quad \text{$x = 1/2$}\\   1 & \quad \text{ $x\in (1/2 , 1]$}\\    \end{array} \right.  $  I am finding it difficult to prove that $f_{n}$ is Cauchy in $(C[0,1], d_1)$.  I need help to solve this problem.  Edit: I am sorry i have to show $f_n$ is cauchy  Thanks for helping me.


Can someone please help me to understand, why for non-template classes, it is recommended to separate code in header and source file? Is that only code styling or does this approach avoid possible errors (e.g., linker errors)?  I'm wondering since in case of template classes, we are not even allowed to do the separation.   Many thanks in advance!

Why does C++ have header files and .cpp files?


I want my design to use as many common footprints as possible (eg. 0805/0603 for capacitors and resistors, powerSO8 for big switching MOSFETs, etc) so that I am less restricted by manufacturers and suppliers, and so that people in other countries etc. can build the design easier.  It appears that HC-49 is a very common footprint for crystals across a wide frequency range. I am also aware of a (less common) SMD version where it sits on a little plastic base and the leads are bent flat.  Are there any more compact SMD packages for crystals that have the broad support across many frequencies and suppliers? When I look on DigiKey it seems that all the smaller devices are in unique/manufacturer-specific packages with fairly narrow ranges of frequencies.  Am I just missing something? Is there a "go-to" package for small SMD crystals, like there is for resistors? Or perhaps a few different "go-to" packages for different frequency ranges (since lower frequency xtals probably need to be physically larger)?  (To clarify, I have no issues with reflow-only packages)

There is an old and bog standard form factor for SMT crystals - HC49/US. The problem is that HC49/US takes a lot of real estate on the board.  It's 12mm long.  Another problem with crystals and oscillators in general is that they often become long lead time items.  [This is my experience.]  There are lots of small form factor crystals from various manufacturers.  But, at a glance, it seems that there is no standardization of form factor.  It’s nice when packages are standardized.  It alleviates the long lead time problem.  Crystals from manufacturer B may be used, if crystals from manufacturer A are out of stock.  Are there standard form factors for compact SMT crystals?  Update  Armed with the insights from Gribo and Gustavo, I did a more focused survey.  Found that 12MHz in 3.2x2.5mm package are produced by: Abracon, Citizen, Epson, Fox, ECS, TCS, NDK.  To be included in this list, the part had to be in stock at DigiKey.  It turns out that 3.2x2.5mm package is common across many manufacturers.


I'm trying to extract foo from the string "foo-bar-baz" in bash.  Any ideas how to do it using string substitution or something similar (without external tools).  I tried this but it didn't work:  $ str="foo-bar-baz" $ echo ${str%-*} foo-bar   This also not work:  $ str="foo-bar-baz" $ echo ${str#*-} bar-baz   Any ideas how to get just bar?

I'm quite confused about the following regular expressions I found in a shell script:  ${0##*/} ${0%/*}   How do they work?


I have a piece of data, in this case, Toyota. I have 2 owners, foo & bar. Each owner has about completely different 50+ tables each. All I know is the data, Toyota is in one or more of the 2 owner's tables. The challenge is, I am trying to find where Toyota came from, from the database. How can I select the tables, column name, and owner which contains the data Toyota? I understand from context Toyota is a car manufacture, so I was doing something like this, but then I have to manually check if that the particular table/column has the data Toyota. Also what if the column name is car_man, then my statement below completely doesn't work. select table_name, column_name, owner FROM all_tab_columns where (owner = 'foo' or owner = 'bar') and column_name LIKE '%manufacture%';

Is it possible to search every field of every table for a particular value in Oracle?  There are hundreds of tables with thousands of rows in some tables so I know this could take a very long time to query. But the only thing I know is that a value for the field I would like to query against is 1/22/2008P09RR8. <  I've tried using this statement below to find an appropriate column based on what I think it should be named but it returned no results.  SELECT * from dba_objects  WHERE object_name like '%DTN%'   There is absolutely no documentation on this database and I have no idea where this field is being pulled from.  Any thoughts?


I have a daughter and two younger sons; they are all marrying geniuses.   My oldest son is inheriting everything and he is an imbecile. My oldest son isn't a traitor so I have no legal rights to imprison or execute him; he's just very unwanted.  How can I make my daughter or younger son an heir, instead of my oldest (imbecile) son?

Everything was perfect. I have a good and young ruler, who has passed on some good genes to his sons. I also had a lot of spare lands, so I could make my heir a duke and doubly count when he came of age.  My mistake was to marry him off to some scheming wench. I knew it would end like this, but her stats were just too great to resist!  Anyway, a few years down the road, and my trusty spy master lets me know that my beloved son is looking to usurp me. Not cool! I demand that he end the plot, and decide to see how this develops.  Shortly thereafter, he suddenly dies (not by my hand — likely the wife is the culprit). My second eldest son becomes my new heir and favourite, however all the titles are inherited by my clubfooted grand daughter aged two. Curses!  Now, what I really wanted, was to imprison and disown my traitorous son followed by swift justice of the axe. Not sure what my other vassals would think of that idea, but I had a just reason for imprisonment at least.  Option number two, is to start plotting for my dearly beloved grand daughters untimely demise, but I'm not sure how that would work out either.  The situation is this. I'm young (40ish) and well-liked. I have a new heir, but I'd prefer to keep my lands for myself and give him the ones of the previous heir — one duchy and two counties currently held by my grand daughter. The duchy can be revoked free of charge, as I hold a claim to it. She has no siblings. I am da King. I have limited crown authority, but can bump it up to medium if it suits me.    So my questions to you are as follows:   Is it possible to disown a son, considering I have just cause for imprisonment? An execution would of course settle the deal, but my other vassals would probably find me "cruel". Is it possible to plot against a character which is not yet of age? What would happen if she suddenly died with no heir? Would all her titles be returned to the king or duke (i.e. me)?   EPILOGUE I had savegames before and after, so I decided to test a few things.   I could imprison my quisling of a son. I could also seize all his titles and banish him from my lands, but he would remain an heir, even if he wasn't officially a prince. I guess I could have let him rot in jail, as it seems prisoners often die in custody, but it would be a risky bet. After the unfortunate death of my old heir, it seems some strange rules apply regarding the remaining titles. The dukal title I could simply revoke for free (although at a opinion penalty from the duchess). Should she die today, one of the counties would be inherited by her younger sister, and the other would be inherited by me.   I found this to be an interesting development: Turns out my new heirs wife suddenly died. Who did he marry, other than the same scheming hag who presumably killed off his brother, and made an attempt at me? By a suspicious coincidence, I died not very long after. Such is the effects of the deceitful and ambitious traits combined with a really dope intrigue stat. ;)


I am trying to determine the right frame size for myself before purchasing a hybrid bike. My height is 174 cm and I have an inseam size of 85 cm. If I go by the height it should be a medium frame between 43-47 cm but if I go by the inseam height, recommended frame size is 58 cm! Apparently, the latter is wrong but I wonder why there is so much difference between two calculation methods.

Today I disassembled my current fixed-gear, and reassembled all the parts in another frame, which I am considering to purchase.  The current owner of the frame warned me that it might be too big for me, and I agree with him. Even though, I think it has good cost-benefit, so I decided to do a test-ride.  I noticed the final geometry and rideability was pretty good, and since the frame has a long headtube (which I desire) I guess the inseam problem might not be so important considering the main goal is randonneuring, where "riding" characteristics are much more important than "mounting and dismounting" characteristics. Most probably the bike will receive a drop handlebar, even though I like flat bars a lot.  Below is a photo of the current set. There are 6cm of seatpost visible, and I might want to lower an aditional 1cm. The main reason I want to somewhat stubbornly keep the frame is that I liked riding it, didn't see any major problem except for a slight touch of the upper seatstays between the thighs, but that tends to disappear since I felt the need to put the saddle a bit more forewards.  What I am asking is:     Even considering the frameset is ridiculously larger than I would   typically choose, if I like riding the bike, is there any problem that   I'm not considering, a reason NOT to keep the frameset?   I'm 1,88cm (6'3") tall, and have used 56cm bikes, this one is 64cm (seat tube, bbc to top).  Thanks for any insight!


I have the following javascript code which does a sum of strings converted to floats:  $(document).on("change", ".changeValue", function (e) { $(this).closest(".mdl-textfield--floating-label").find(".emptyRateError").css("display", "flex").css("visibility", "hidden"); var elemClass = $(this).Get_Attr_Regex('optionValue_', 'class'); var elemSum = $(".optionSum_" + elemClass.substring(elemClass.indexOf("_")+1, elemClass.length)); var sum = 0; $("." + elemClass).each(function (index) {     sum += parseFloat($(this).val()); }); elemSum.val(sum);   });  However, at times, when I have values "1.2" and "4.4", the value returned as sum is 5.6000000000000005.  Any idea why I am getting this behaviour? Thanks

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I bought individually wrapped steaks from Walmart, and I accidentally left them out of the freezer for about 18 hours. I don't know if they had completely thawed or not. I didn't  open the box to look.      I didn't have time to cook them, so I put them into the freezer.   They are frozen now... but are they safe to eat?    EDIT:  I recieved a response from Black River themselves asking the same question. Their official response was:     Thank you for your email I received regarding a recent purchase you   made. I have spoken to my product and development team and they   suggest for you not to consume that product. Having the product out   for 16 hours not refrigerated isn’t a good thing so we wouldn’t   recommend for you to consume it.       Having said that you also stated that you re froze the product which   isn’t a good thing to do since the product thawed.      We believe 8   hours would be sufficient enough to thaw this product so we don’t   recommend you consuming this product.      I hope I was able to answer your question. If for any reason you have any further   questions/concerns please feel free to contact me as I am willing to   assist you with any information you may need.      Black River Angus Ltd   1-888-422-9656

If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more?


I've seen videos on how all one has to do is press Ctrl + A to select an entire bunch of images to create/edit a movie in the VSE from images. However, that was in an older version then 2.77.  There has to be a better way to grab all of the images when adding strips/images in the video editing. I rendered 30 secs of video, taking 5 hours, and ending up with 900 images. When I went to add them all to the Add Image Strip section in the File Browser, Ctrl + A did not work. Selecting the first image then holding the shift button and clicking on the last image did not work, either.   Keying B for Box Select did not work properly because it does not drag through all of the images (it only selects the ones that you can see within the defined box).  Basically, what is the proper way to import all of the images at once into the video editor?  I can provide screenshots if you guys need them.

I usually use the Blender VSE for my normal video editing (for lack of After Effects).  I also usually render directly into AVI format, not PNG sequences of frames. I would however like to move to PNG sequences, because it's a lot easier to sort out any mistakes and to edit that way.  I would therefore like to load the sequences I render into the VSE quickly and easily (30fps) - which would normally require tweaking of every frame because they normally when added add an image strip which is 25 frames long (and I want each frame to be 1 frame long) - I can also only add one frame at a time.  How can I load a frame sequence into the VSE?


How to get table2 records that don't exists in table1 (date filtered)  SELECT e.event_id, e.start_time, te.*  FROM table1 te, table2_tmp e  WHERE te.book_id = 45  AND (DATE(STR_TO_DATE(e.start_time,"%Y%m%d%H%i%s")) BETWEEN DATE(DATE_SUB(NOW(),INTERVAL 1 YEAR)) AND CURRENT_DATE)   table1  ID      event_id  start_time      book_id 10000   1_1005    20191222135100  45  <-- date Filtered & Doesn't exists in t1 10001   1_1006    20200123139100  45 10002   1_1007    20200124145100  45 10003   1_1010    20200125135100  45 10004   1_1015    20200325135100  46   table2  ID      bk_event_id   11111   1_1006    11112   1_1007          11113   1_1015 11113   1_1016   Expected result  ID      event_id   10000   1_1016


Why direction of Ampere's Law follows right hand rule?

I am currently wondering about the famous .  Where does it come from mathematically that when you point with your thumb in the direction of the current, your curved fingers will point in the direction of the $B$-field? In other words, which mathematical operation does it come from? Probably it has to do with some vector product or Stokes theorem application, but I am not quite sure about it.


I an running Unity version 7.4.0+16.04.20160906 under Ubuntu 16.04.2  I would like to have the user name (or user ID number) displayed on the desktop (not in a window or any of a window's decoration) as soon as it starts up and perpetually thereafter.  After switching user, even for the first time (especially when that user first logs in) it should immediately show as soon as anything shows.  It does not need to show when the screen is black just before the display begins.  An ideal location would be somewhere along the title bar at the top.  How can I do this?

I would like to see my username in the top panel of Xenial Xerus. By default it is not present, as this screenshot demonstrates:    How can I place the logged in username there and then easily reverse this if I want? I am interested in both command line and gui solutions.


The total number of ways which 5 balls of different colors can be distributed among 3 persons so that each person gets at least one ball is..?  My attempt: So, first we can choose any three balls to allocate to any person, so $\binom{5}{3}$ and, then distribute them then in 3! ways. And, so we have, $\binom{5}{3} \cdot 3! $. Now I have two remaining balls and this I can give randomly to any of the three people. For the first ball I have three choices and so do I for the second ball. Hence,  The net number of cases is $ \binom{5}{3} \cdot 3! \cdot 3^2$ Now, I know that like the thing can happen in reverse. For example distributing three then distributing two, I could have some overlapping cases where the items which are distributed in the distributing two case is actually distributed in the distributing three step. How do I account for the overlapping case? Ans: 150 Stars and bars attempt: We have five objects and introduce two objects as dividers, subtract cases where one guy gets nothing (3 x 6!) and add cases where two people get nothing and third guy everything (3) What I am looking for : A fix to this method such that it gives me the correct answer, in the other stack post linked to this one, it has ample amount of methods based on other ways to solve it but my question here is how to fix this method.

How many ways are there to distribute 5 distinguishable balls between 3 kids such that each of them gets at least one ball?   My approach is $ \binom{5}{3} 3! $ + $ \binom{2}{2} \binom{3}{2}2!$ which is equal to $66$?


What do I have to set to get a coordinate sytem like   MWE:    \documentclass[]{standalone} \usepackage{tikz} \usepackage{tikz-3dplot} \begin{document} \tdplotsetmaincoords{60}{110} %\tdplotsetrotatedcoords{30}{45}{0} %\tdplotsetcoord{point}{1}{33}{44} %\tdplotsetrotatedcoords{00}{0}{0}  \begin{tikzpicture}[ tdplot_main_coords, %tdplot_rotated_coords, ] \foreach \P/\s/\Pos in {(1,0,0)/x/below, (0,1,0)/y/left, (0,0,1)/z/right}  \draw[-latex] (0,0,0) -- \P node[\Pos, pos=0.9,inner sep=2pt]{$\s$}; \end{tikzpicture} \end{document}

Typically when drawing a 3D figure on paper (or a black/white board), a mathematician draws the z-axis to point due north on the page, the y-axis to point due east, and the x-axis to point due southwest (as if coming out of the page). And then the 3D objects are drawn on that; e.g., when a sphere is drawn on those axes, it looks head-on like a circle, without distortion, so that its cross-section in the yz-plane is a perfect circle.  In the answer  by @Max to my question , he shows how to create a 3d set of axes that look like that, using a Cabinet projection.  However, when the Cabinet projection is applied to a sphere, it distorts the sphere's shape, as he shows.  Is there a way to create with TikZ a 3D drawing that does draw the axes as I've described, but does not distort solid object such as a sphere?


This is a question from hackerank i've some doubt in the code i have written : Sample Input  : 01:23:32PM Sample Output : 13:23:32 import java.util.Scanner; public class Solutions {     public static void main(String[] args) {         Scanner sc = new Scanner(System.in);         String time = sc.nextLine();         int n = time.length();         String session = time.substring(n-2);         if(session == "AM") {             if(time.substring(0,1) == "12") {                 String x = time.replace("12","00");                 String y = x.substring(0,n-2);                         System.out.println(y);             } else {                 System.out.println(time.substring(0,n-2));             }         } else if(session == "PM") {             if(time.substring(0,1) == "12") {                 System.out.println(time.substring(0,n-2));             }             else {                 String hour = time.substring(0,2);                 int newformat = Integer.parseInt(hour) + 12;                 String newTime = String.valueOf(newformat);                 System.out.println(time.replace(hour,newTime));             }         }     } }

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 am using postgres with postgis and I have a set of points which I would like to interpolate with a set of lines.   Now my problem is that the set of lines are of type multilinestring.   Is there a way to convert them to linestring?


Let's say you're a level 8 druid, so you have 4 hours per use of Wildshape. Now, at 11:00, you expend one use of it to turn yourself into a Raven (or any other beast). From 12:00 to 13:00, you take a rest, while still being in your raven form ().  Obviously, you can stay in raven form until 15:00, at which point you revert to your regular form.  Then, from 13:00 to 15:00, you are in raven form. The PHB states on Wildshape:     You can use this feature twice. You regain expended uses when you finish a short or long rest.   You just finished a short rest, meaning you would still be transformed and get both uses back (assuming you expend your use of Wildshape when you transform, not when you end it, which would make this question irrelevant). This might not be a balancing issue if you're a CR0 raven, but it might very well be relevant for other Wildshapes.  Hence my question:  If you finish a short rest while Wildshaped, do you get both uses back and can therefore "overstock" your total maximum Wildshape time per rest?  Or would you simply auto-expend one use, and reset the timer on that use?

Do the druid's uses of the Wild Shape feature recharge while still in Wild Shape?  Say a 10th-level Circle of the Moon Druid spends two uses of Wild Shape to transform into an Air Elemental, whose form she can stay in for the next 5 hours. After 2 hours, she takes a short rest, but does not drop the Wild Shape. She has another couple of hours to keep the Air Elemental form.  My main concern: Does she get her two uses of Wild Shape back with that short rest? Or, does she have to drop the Air Elemental form first before taking the short rest to recharge Wild Shape?


What is the best system/application to create documents (e.g. PDF Brochures, JPG flyers, posters etc.) so that a client can edit the text content whilst still limiting certain things which they cannot touch (i.e. a logo or image).

A client needs me to design a brochure for her. The problem is that she wants to edit and change the text and maybe also change some of the pictures herself.  However, she doesn't have any of the Adobe software or the knowledge to use these.   Is there any alternative?


New to this but tried pretty much everything - but do I need an actual physical removable CD in order to install Ubuntu inside VirtualBox?

I would like to know if anyone can help me with installing Ubuntu on VirtualBox


It is said that making the polyjuice potion Harry, Ron and Hermione were breaking at least 50 rules of the school. Now, Hermione accidentally drinks a potion with an addition of cat's hair, which sends her to the hospital wing for weeks. How did she justify accidentally turning into half a cat? If she admitted or was found guilty of brewing the polyjuice potion, why weren't all three punished in some way? I know the book says that Madam Pomfrey "never asks too many questions" but for sure the voice of the accident would have spread, especially since the only place they could have gotten the ingredients is stealing them from Snape, and judging by the fourth book, he discovers this kind of stuff.  It looks like the cat accident with the polyjuice potion isn't that relevant to the story and it introduces an unnecessary plot hole. Has anyone solved this?

In HP and the Chamber of Secrets, Harry, Ron, and Hermione  by brewing Polyjuice Potion and drugging and impersonating other students, just in order to get into the Slytherin common room and probe Malfoy for information about the Chamber of Secrets.  Is this little adventure ever discovered by Those in Charge (teachers)? Or even by Malfoy?  If so, did they ever get punished? I can't see how they could fairly have avoided it (other than they're the Golden Trio and always do). In the end they don't actually get any useful information, except that Malfoy isn't the culprit. This escapade doesn't help them at all in their eventual discovery of the culprit and destruction of the Basilisk. It was just motivated by their suspicion of Malfoy, which was essentially based on "he's Slytherin and we don't like him" and turned out to be unfounded.  If not, how could it remain undetected? Hermione's skill with Polyjuice Potion is eventually common knowledge ... more importantly, why didn't Crabbe and Goyle run to tell someone when they woke up and found they'd been drugged? Did the topic never come up between Malfoy and the pair of them, with Malfoy realising he'd been talking to impostors? What did they tell Madam Pomfrey about Hermione's semifelinity after her failed attempt to Polyjuice herself into Millicent Bulstrode?


I am installing a 32bit app on 64 bit Windows 7. The app requires VC++2013 Redistributable to be installed and directs me to Microsoft Site.  There are two versions of VC++ 2013 Redistributable 32 & 64 bit. However what I need to know is what is really applicable for a 32 bit app on 64 bit Windows?  Thanks

If I have both the x64 and the x86 version of a Microsoft C++ Redist package, can I uninstall the x86 version? If I did uninstall the x86 version, would the x64 version cover the dependencies on the x86 package?


I have route list as result of pgRouting with street names. How to get messages "Turn left", "Go along" etc ... Can pgRouting do this or I need some other source and which?

Would like to emulate google maps' driving directions functionality but use pgRouting instead. google's data over the project area & scale is quite a bit off so we want to use our own transport network data in postGIS.  any hints?  thanks.


So my problem is that my mac is not booting up. Also,the OS X recovery HD is not available. Also, the internet recovery is not detecting my WiFi .. so i intend to clean install Yosemite on my mac. I have the Yosemite.app and a boot-able USB and windows. But i don't know how to install from the .app file . please help

I have a 2009 Mac with a new blank SSD. I have a Snow Leopard install disk but it doesn't work (it was a replacement installer disk and has never worked), so I don't have a working OS X install.  I do have a Windows 7 machine.  How should I go about installing Yosemite? All instructions I can find require OS X at some point in the process. I can't even download it from the store unless I'm on a mac.


After installing Linux Ubuntu 14.04 on a new Lenovo V580c, I can't install Broadcom Wi-Fi adapter driver. After "Applying changes..." nothing happens.  lspci -nn | grep 0280  03:00.0 Network controller [0280]: Broadcom Corporation BCM43142 802.11b/g/n [14e4:4365] (rev 01)

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.   What are the steps to install Broadcom wireless drivers for a BCM43xx card?  I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.    lspci -vnn | grep Network showed:   Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b]      iwconfig showed:  lo        no wireless extensions. eth0      no wireless extensions.   NOTE: Answer below is updated every time new information is added and confirmed working.


How can I change leading zero in umask 0022? Can it be changed? I searched the usual methods for information and my local system was of little help. $ man umask   No manual entry for umask    $ umask --help bash: umask: --: invalid option umask: usage: umask [-p] [-S] [mode]  I found an  with the following:  umask [-p] [-S] [mode] mode ... File creation mask -S  ........  Print the mask in symbolic format -p  ........  Output in a form that can be reused as input  Based on this, I tried a few basic umask commands: $ umask 0022  $ umask -p umask 0022  $ umask -S u=rwx,g=rx,o=rx  I was surprised to find that I could not run umask with sudo $ sudo umask   [sudo] password :   sudo: umask: command not found    I changed the regular umask as follows: $ umask 021 $ umask 0021  $ umask 0022 $ umask 0022    Finally, I hit an error while trying to change the leading zero $ umask 1022 -sh: umask: 1022: octal number out of range    So, back to my original question, how does one change the leading zero (0)?  Is it for the super user (root)? Can it be updated, and if so, to what? I reviewed a similar question  and found:  I don't know that you would unmask the first bit with umask, but technically you could ...  and  I don't believe you can actually set the umask to allow you to enable any of these extra bits by default  So, these uncertain and contradictory statements do not answer this question.

So I know umask can restrict privileged users, using this format umask ugo.  I understand that the read = 4, write = 2, and exec = 1. However, when I type umask, it returns 4 digits which is 0022 or 0073. I have no understanding of how does this work now because there is an extra digit. What is that extra digit and what does 0022 mean?


I'm struggling with this question and was wondering if anyone could help. Thanks! When a polynomial $P(x)$ is divided by $(x-2)(x+4)$, the remainder is $(3x-5)$. What is the remainder when $P(x)$ is divided by $(x-2)$? Any help would be greatly appreciated! Edit: This is my attempt so far: I have expanded $(x-2)(x+4)$ which gives me $x^2+2x-8$ but  for remainder theorem it is $f(x-a)$ remainder so it's a bit different, hence I don't know how to proceed. I also thought of doing $P(x) =  (x^2+2x-8)Q(x) + 3x-5$ but don't know where to go from here.

When the polynomial $P(x)$ is divided by $x^2 -1$, the remainder is $3x-1$. What is the remainder when $P(x)$ is divided by $x-1$?  I'm not sure what to do. I know that $P(1)=P(-1)=3x-1$, but I don't think that's how you're supposed to do it.  Any help would be appreciated, thanks.


I've been wanting this forever, but today is the first time I've ever noticed apt downloading more than one update at a time:   Is this now a thing? Where can I read more about the extent of this new feature? I can't seem to find out anything about this so far in my internet searches.  FYI, I'm running Kubuntu 19.10.

I'm painfully watching my apt dist-upgrade command download each package in a very long list, and what makes it painful is that packages are downloaded one-by-one. I fail to see why this process couldn't be sped up by downloading multiple packages simultaneously!  For example, if apt is downloading Chrome (PPA), Syncthing (PPA), and Ubuntu system updates (non-PPA), three simultaneous downloads will begin, one for Chrome, one for Syncthing, and one for the Ubuntu system updates.  Since all update packages are downloaded before any installation even begins, I don't see any reason why multiple packages for Ubuntu system updates coming from a single repository can't be downloaded in parallel.  I would really like to know if anyone knows a way to make this happen? Can I downloaded multiple package upgrade files in parallel from a single repository when running apt dist-upgrade or apt upgrade?


Find $$\sin\left(\frac{2π}{7}\right)+\sin\left(\frac{4π}{7}\right)+\sin\left(\frac{8π}{7}\right).$$  I already know of two methods. The first is in which we let $2π=7\theta$ and proceed as such- $\begin{align} 2\pi-3\theta=4\theta\\ \implies\sin(3\theta)+\sin(4\theta)=0\\ \implies-4\sin^3\theta+3\sin\theta+ 4\sin\theta\cos\theta(1-2\sin^2\theta)=0 \end{align}$ On solving further we get a cubic polynomial in $\sin^2\theta$. We can then find the required sum from the sum of roots and some algebra. I also know of the method that involves complex numbers and the roots of unity. What I am interested in is a method involving trigonometric identities. I tried a few things. In particular I noticed one fact that might be of significance, that is the sum of the angles $\frac{2π}7, \frac{4π}7$ and $\frac{8π}7$ is precisely $=2π$. However, I was not able to make much progress. Can someone please help me with this?

Find the value of $\sin\frac{2\pi}{7}+\sin\frac{4\pi}{7}+\sin\frac{8\pi}{7}$  My approach :   I used $\sin A +\sin B = 2\sin(A+B)/2\times\cos(A-B)/2 $  $\Rightarrow \sin\frac{2\pi}{7}+\sin\frac{4\pi}{7}+\sin\frac{8\pi}{7} = 2\sin(3\pi)/7\times\cos(\pi/7)+\sin(8\pi/7) $  $= 2\sin(3\pi)/7\times\cos(\pi/7)+\sin(\pi + \pi/7) $  $= 2\sin(3\pi)/7\times\cos(\pi/7)-\sin(\pi/7) $  I am not getting any clue how to proceed further or whether it is correct or not. Please help thanks..


So as stated above I have this equipment: Canon 6D, Canon 600 EX RT, Yongnuo YN622C TX and YN622C Flash.  I want to take the Canon flash off the camera to have a simple portrait setup. I have the Yongnuo YN622C TX ETTL flash controller attached to the 6D, I have the trigger with the Flash (all channels A1) and the fire test works but when I focus and press the shutter the flash doesn't fire. I have the flash set to optical slave.  What should I do?

I have a Canon 700D and YN-568EX ii external flash that I am using in slave mode. But whenever I try to fire the built-in flash pops up automatically and fires itself. Is there any option to use only external flash?


I dropped my computer and now when I start it up it says:      Reboot and select proper boot device or insert boot media in selected   boot device and press a key.   I thought turning it back off, then on would work, but I get the same thing. I have a Toshiba.   What should I do?

My computer no longer boots Windows or the installed operating system. Instead, I may get this error:  PXE-E61: Media test failure, check cable -or- Check cable connection!  PXE-M0F: Exiting PXE ROM.   and/or one of the following messages or similar:  Operating System not found  No boot device available- No bootable devices--strike F1 to retry boot, F2 for setup utility  No bootable device -- insert boot disk and press any key  No Boot Device Found. Press any key to reboot the machine  Default Boot Device Missing or Boot Failed  Reboot and Select proper Boot device or Insert Boot Media in selected Boot device   What does this mean and what can I do?     This question comes up often and the answers are usually the same. This post is meant to provide a definitive, canonical answer for this problem. Feel free to edit the answer to add additional details.


When there is a rubber-protector around the phone or the tablet, I find it extremely difficult to do a palm-swipe-to-capture action,  to get a screenshot.   That's due to the fact that the raised edges of the screen protector prevents my palm to completely flush on the surface of the phone.   Is there a way to get the screenshot any other way and a more convenient way?  Or an app that will do that? matye thru share via route??

Is there a way to take a screenshot of an Android device and save it as an image file?


I am currently working on an Android app with Android Studio. I followed a Tuto to add the facebook login functions with picture and username . Then I created a new Activity once the Login is successful. But when I start the app, the app crash within 5 seconds with the message Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference  Main activity :  public class MainActivity extends AppCompatActivity {  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);      Bundle inBundle = getIntent().getExtras();      String name = inBundle.get("name").toString();     String surname = inBundle.get("surname").toString();     String imageUrl = inBundle.get("imageUrl").toString();       if (AccessToken.getCurrentAccessToken() == null) {         TextView nameView = (TextView)findViewById(R.id.nameAndSurname);         nameView.setText("" + name + " " + surname);         new DownloadImage((ImageView)findViewById(R.id.profileImage)).execute(imageUrl);          goLoginScreen();     } }  private void goLoginScreen() {     Intent intent = new Intent(this, LoginActivity.class);     intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);     startActivity(intent); }  public void logout(View view) {     LoginManager.getInstance().logOut();     goLoginScreen(); }   Activity_main.xml :  <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="tech.alvarez.androidfacebooklogin.MainActivity">   <TextView     android:id="@+id/nameAndSurname"     android:layout_width="77dp"     android:layout_height="wrap_content"     android:layout_above="@+id/profileImage"     android:layout_centerHorizontal="true"     android:layout_gravity="center_horizontal"     android:layout_marginBottom="-143dp"     android:textSize="22dp"     android:textStyle="bold" />  <ImageView     android:id="@+id/profileImage"     android:layout_width="87dp"     android:layout_height="101dp"     android:layout_alignParentBottom="true"     android:layout_centerHorizontal="true"     android:layout_gravity="center_horizontal"     android:layout_marginBottom="190dp" /> <Button     style="@style/Widget.AppCompat.Button.Colored"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignParentBottom="true"     android:layout_centerHorizontal="true"     android:onClick="logout"     android:text="@string/logout" />

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I'm trying to install Skype on Ubuntu 14.04 32-bits.  I have already tried :    downloading from the Skype website  But there is only a 64-bit version available. I have enabled Canonical partner in Other software in Software and Updates and run  sudo apt-get update sudo apt-get install skype   that returns:  Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package skype  also tried :  sudo apt-get update --fix-missing sudo apt-get install skype   but I get the same problem...    Thanks for any help!

I'm having trouble installing Skype. I have Canonical Partners enabled in Synaptic Package Manager, but skype is not showing in the search. If I try to install via:  sudo apt install skype   I get:   E: Unable to locate package skype   I went to the Skype web site and it offered a .deb file only in 64 bit.


Does a zero vector by itself constitute a subspace? It appears to satisfy all 3 conditions.   Contains zero Hold under addition Holds under scalar multiplication   Can any other single vector do that?

W is a subspace of $\mathbb{R}^n$ iff   The zero vector ∈ W. X + Y ∈ W for any X, Y ∈ W. aX ∈ W for any X ∈ W and a ∈ R.   So, given W = { X : X = [x1...], x1 = 0, x2 = 0, ... xn = 0 } ∈ Rn   The zero vector ∈ W because each X in W is the zero vector by definition, X + Y ∈ W because [0...] + [0...] = [0...] aX ∈ W because a[0...] = [0...]   So if I understand this correctly, the zero vector is itself a subspace of $\mathbb{R}^n$. Is this correct?   In addition, can this be extended to say that for any W = { X : X = [$x_1$...] } ∈ $\mathbb{R}^n$, assuming W is a subspace of $\mathbb{R}^n$, $x_i$ (an arbitrary component of W) can only be a constant if it is 0? (I.e., $x_i$ can't be 1 or 2, but can be 0)


I have a mailserver that should resolve everything from mydomain.com to an internal DNS server and everything else (to send email) from an external DNS server. The internal DNS server can't resolve (forward) from the public internet.  It appears to me that that can't be done in resolv.conf and i wonder if i need to setup DNS locally on that mailserver.  Or are there other ways?

I'll try to explain this as best I can...  I'm on ubuntu 13.04, and I am running a local BIND instance at 127.0.0.1 for access to basic wild-card DNS for development (i.e. "*.dev == 127.0.0.1" - yes, I know, don't create fake tlds, etc. This is entirely local to my machine, though).  I also have clients who have their own DNS servers set up through a VPN (at 192.168.140.111 or something similar).  My problem is that if my resolv.conf has their DNS server listed first, I can't access my *.dev, and if I have my DNS server listed first, I can't access their *.vpn records.  Currently, this is my resolv.conf:  # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN nameserver 192.168.140.111 search ns1.vpn nameserver 127.0.0.1 nameserver 127.0.1.1 search fritz.box   The first three lines of the config are in /etc/resolvconf/resolv.conf.d/head, so they'll survive through a resolvconf -u.  Essentially what I want to know is this: is there a way for me to set this up so *.dev goes to my dns server, and *.vpn goes to theirs, (and everything else goes off to my ISP).


I can't find the problem. I'm programming an chess game and I want to display the moves made by the player. For example: E4 to E5. The code below compares an old String before something moved with a new one. The problem is I´m using lower case letter for the black figures and upper case letter for the white figures, now I want to tell the player what figure he took. It is not relevant what kind of color the figure had. Because of that I´m making the letter upper case and compare it in an if statement if it is a "P" or a "K" or so on. But it doesn't work. .toUpperCase is working but it always fail at the if statement. It isn't a big problem I can use an or for asking the upper and lower case but I really want to know what the reason is. I hope someone can help me and sorry for my bad english skills.  package projekt;  public class MoveList {     private String startPosition;     private String endPosition;     private String[][] position =     {             { "A8", "B8", "C8", "D8", "E8", "F8", "G8", "H8" },             { "A7", "B7", "C7", "D7", "E7", "F7", "G7", "H7" },             { "A6", "B6", "C6", "D6", "E6", "F6", "G6", "H6" },             { "A5", "B5", "C5", "D5", "E5", "F5", "G5", "H5" },             { "A4", "B4", "C4", "D4", "E4", "F4", "G4", "H4" },             { "A3", "B3", "C3", "D3", "E3", "F3", "G3", "H3" },             { "A2", "B2", "C2", "D2", "E2", "F2", "G2", "H2" },             { "A1", "B1", "C1", "D1", "E1", "F1", "G1", "H1" } };      private String[][] chessBoard;     private String[][] oldChessBoard;      public MoveList(String[][] chessBoard, String[][] oldChessBoard)     {         this.chessBoard = chessBoard;         this.oldChessBoard = oldChessBoard;          move();     }      public void move()     {         for (int i = 0; i < oldChessBoard.length; i++)         {             for (int j = 0; j < oldChessBoard.length; j++)             {                 if (oldChessBoard[i][j] != chessBoard[i][j])                 {                     if (oldChessBoard[i][j] != " " && chessBoard[i][j] == " ")                     {                         startPosition = position[i][j];                     }                     else if (oldChessBoard[i][j] == " " && chessBoard[i][j] != " ")                     {                         endPosition = " to " + position[i][j];                     }                     else if (oldChessBoard[i][j] != " " && chessBoard[i][j] != " ")                     {                         endPosition = " take " + position[i][j] + " " + takenFigure(oldChessBoard[i][j].toUpperCase());                     }                 }             }         }         if (startPosition != null)         {             System.out.println(startPosition + endPosition);         }      }      private String takenFigure(String figure)     {         System.out.println(figure);          if (figure == "P")         {             return "Pawn";         }         else if (figure == "K")         {             return "Knight";         }         else if (figure == "B")         {             return "Bishop";         }         if (figure == "R")         {             return "Rook";         }         else if (figure == "Q")         {             return "Queen";         }         else if (figure == "A")         {             return "King";         }         return "Nothing";     } }

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?


Let $a_n$ be a sequence s.t $a_1 > 0 \land a_{n+1} = a_n + \frac{1}{a_n}$. Prove that $a_n$ is increasing and tends to infinity.  Proof:   Consider $a_{n+1} - a_n$:  $a_{n+1} - a_n = a_n + \frac{1}{a_n} - a_n = \frac{1}{a_n}$ This is greater than $0$. Thus, $a_n$ is increasing.  Now this is where I need some help. I would like to say that $a_n$ is unbounded and then conclude that monotone and unbounded implies tending to infinity.  Maybe by contradiction?

Does the recursive sequence $a_1 = 1, a_n = a_{n-1}+\frac{1}{a_{n-1}}$ converge?  Since the function $x+1/x$ is strictly monotonic increasing for all $x>1$, I don't think that the limit converges, but I'm not sure. Can anybody tell me whether the sequence is converging or not?


In Woocommerce, I have product categories A, B, C & D. Categories B, C & D are all child categories of parent product category - A, like so:     Product Category A         Child B   Child C   Child D      I need a simple PHP conditional statement / code that allows me to target and apply code to the child categories of parent category A only.   ie:  <?php    if (cat_is_ancestor_of(A, $cat) or is_category(A)):  ?>   <div id="div>   Do this   </div> <?php endif; ?>   This will not work, since "cat_isancestor_of" doesn't apply to Woocommerce product categories - Woocommerce uses the conditiatonal tag "product_category". For more info on Woocomerce condition statements see this:    I am fully aware of how to target child categories within Wordpress, but again not able to figure out how to do it within WooCommerce & product categories specifically. Any help would be appreciated.

I'm trying to use cat_is_ancestor_of() for custom taxonomy categories but it's not working. Is there any other way to check if a category is child of another?


I've been given the task of finding out why our server is slow. I ran a stored procedure I downloaded called sp_Blitz. It let me know that our database had auto-shrink enabled, and to disable it. So, I did that. I don't know how long it's been enabled, but I'd guess at least 3-4 years. When I checked the fragmentation percent of the indexes, a lot of them were 60% - 99%. I then ran a script to rebuild the indexes and update the statistics, but the fragmentation percent didn't really change for these indexes.  Is there something else I need to do to repair what auto-shrink has done?  Any advice for me?

Closely related to  from a few weeks ago, but the answers didn't discuss how to do the . Here's the situation:  We now 15 GB data in a database, but a logging bug in an application ran wild and ran this up to 80GB data giving us DB files around 130GB. We've fixed the bug, cleared out the affected tables, and I'd like to get some of the space back, maybe bring the DB back down to 40GB or so.  The biggest reason I'd like to do this is so that we can more easily restore backups to smaller drives on virtual test instances.  I get it: Shrink is evil, and will fragment both indexes and on-disk file. I'm sold. This is a one time event.  So how can I minimize the pain? Seems like I should:   Use DBCC SHRINKFILE (DataFile1, 40000); to aim for 40 GB.  Immediately use some smart reindexing to reorganize and rebuild indexes Defrag physical disks   Will that appropriately mitigate the side effects of a shrink? Or is this only going to end up on my application for the Evil League of Evil?


I want to login to a remote system in ubuntu using a script file which will be executed in my system . The script contains the following commands  #!/bin/bash echo 'systemPwd' | ssh myMachine@192.168.0.59   By executing this script I could not log in to the system. It doesn't gets the password from the echo command. But I don't know how to use alternatives.  But I tried this script  #!/bin/bash sshpass -p 'systemPwd' ssh myMachine@192.168.0.58 <<-'ENDSSH'     #commands to run on remote host     echo 'systemPwd' | sudo -S  shutdown-h now ENDSSH     In the above script the sshpass has been used. The problem is that sshpass has to be installed first. Anyone suggest an alternative method for this which would make me to connect to remote system without sshpass.

I tried writing a shell script which can do automatic login into a ssh server using password which is mentioned in the script. I have written the following code:  set timeout 30 /usr/bin/ssh -p 8484 root@172.31.72.103 expect  {    "root@172.31.72.103's password"     {       send "password\r"     } }   This code is not running properly, still it is asking for the password. Can somebody please help me in solving this


So I used UNetbootin to install a Live Ubuntu 16.04 on my hard disk. When booting up it keeps saying this: /dev/sr0:- no medium found It also says: unable to find a medium containing a live file system Please help. Thanks!

This is the third time I've tried to install Ubuntu Server 14.04.03 64-bit on the same laptop, and each time it caused different problems.  Each time I wrote the same iso image to a USB flash drive by using a different application and OS.   Universal USB Installer (pendrivelinux.com) from Windows WinImage writer from Windows built-in image writer from Linux Mint 17.2    The iso image is the same in all three cases, the USB flash drive is the same, and the laptop is the same. However each time the installation of Ubuntu gave me different installation options. For example, the last time I installed Ubuntu, it didn't show all the packages to choose while installing (Basic Ubuntu server, etc.).


Someone suggested a reasonable edit to a question of mine. Unfortunately it got rejected:    Is there an easy way for me to still apply this edit, without re-typing the key tags?

A nice user suggested  to . The edit, though very good and desirable, was rejected. I do not understand the reasons, and I did not find a way to contact those people who rejected it. What can I do to re-approve the edit?


Im having problems with float data type in getting 1 or 2 decimal places only..  but if you look at the code seems okay to me but the output is different.. I dont want to convert into string yet co'z I need to do something else before the printing them out..  Just for testing purposes I did this literally. There are variables and workarounds just to simplify everything. It suppose to end at 12.8 but it yields 12.8000001 that's why it skips my testing..  float oh=11.0f;     int retval=1;       while (oh<=12.8)         {         //System.out.printf("%-11s",dec_format.format(oh)+'K');      System.out.println(oh);         oh=oh + 0.3f;      }   output is: 11.0 11.3 11.6 11.900001 12.200001 12.500001  It should end at 12.8 and why with ....00001??

What I would like is a method to convert a double to a string which rounds using the half-up method - i.e. if the decimal to be rounded is 5, it always rounds up to the next number. This is the standard method of rounding most people expect in most situations.  I also would like only significant digits to be displayed - i.e. there should not be any trailing zeroes.  I know one method of doing this is to use the String.format method:  String.format("%.5g%n", 0.912385);   returns:  0.91239   which is great, however it always displays numbers with 5 decimal places even if they are not significant:   String.format("%.5g%n", 0.912300);   returns:  0.91230   Another method is to use the DecimalFormatter:  DecimalFormat df = new DecimalFormat("#.#####"); df.format(0.912385);   returns:  0.91238   However as you can see this uses half-even rounding. That is it will round down if the previous digit is even. What I'd like is this:  0.912385 -> 0.91239 0.912300 -> 0.9123   What is the best way to achieve this in Java?


When the user presses a close Button that I created, some tasks are performed before exiting. However, if the user clicks on the [X] button in the top-right of the window to close the window, I cannot perform these tasks.   How can I override what happens when the user clicks [X] button?

How do I handle the window close event (user clicking the 'X' button) in a Python Tkinter program?


Let $a_n,b_n\in \mathbb R$ such that for each $n$ we have $(a_n+b_n)b_n\neq 0$ and both the series $\sum_1^\infty \frac{a_n}{b_n}$ and $\sum_1^\infty (\frac{a_n}{b_n})^2$ convergent then prove $\sum_1^\infty\frac{a_n}{a_n+b_n}$ is convergent.  I tried writing $\frac{a_n}{a_n+b_n}$ like $\frac{\frac{a_n}{b_n}}{\frac{a_n}{b_n}+1}$ but I don't think if this is enough and I don't know how $(\frac{a_n}{b_n})^2$ appears.

Let$a_n,b_n\in\mathbb R$ and $(a_n+b_n)b_n\neq 0\quad \forall n\in \mathbb{N}$. The series $\sum_{n=1}^\infty\frac{a_n}{b_n} $ and $\sum_{n=1}^\infty(\frac{a_n}{b_n})^2 $ are convergent.  How to prove that$$\sum_{n=1}^\infty\frac{a_n}{b_n+a_n} $$ is convergent.  Thanks in advance


What determines whether something is a "noun adjunct" or just a garden-variety adjective?  Does it matter in any meaningful way?  Here is my hypothesis, but I can't find any authoritative source to back it up. I'm hoping someone here can weigh in more definitively.   Classification of noun adjuncts is based subjectively on whether the word is in "common usage" as a noun.  "Book" and "chicken" are commonly nouns and would be considered noun adjuncts in "book collector" and "chicken soup"; "yellow", not so much. Noun adjuncts may share some common qualities that differentiate them from other adjectives (like not being able to be inflected into superlative forms... one can't be a "book-est collector").  But they are still fundamentally adjectives and may even appear in the dictionary as such if the adjectival usage is common enough.   What I've found so far...  Wikipedia defines a "" as:     an optional noun that modifies another noun; it is a noun functioning as an adjective.   But English words are not decreed to be nouns or adjectives by some higher authority.  So it seems strange that one can prescriptively conclude that something "is a noun" in the first place, let alone extrapolate that it "is a noun functioning as an adjective".  The wiki article cites "chicken soup" as an example of a noun adjunct, but at least  gives a definition for "chicken" as:     adj. (of food) containing, made from, or having the flavor of chicken   So it seems that there are some differing points of view on how to categorize these words.  This question was spawned from some discussion in ,  and .

I read this recently in :     At the end of the summit, the French and European officials had   claimed a points victory over the Germans by getting them to agree   more firmly to a target date of January 1st next year to entrust the   European Central Bank (ECB) with the ultimate authority to supervise   the euro zone’s 6,000-odd banks.   "Points" is a plural, and I suppose it doesn't function as a noun in this sentence since it's following the article "a", so is it an adjective adorning "victory"?


The product of my age 7 years ago and my age 7 years from now is a positive perfect square. Compute my age now. I set up the equation, $(x+7)(x-7)=a^2$, so $x^2 -49= a^2$. So I know that x has to be bigger than 7. But I don't know what to do next... Please help me!  Thank you very much!

This put in the context of a age problem will be:     the product of my age seven years ago and seven years later is some perfect square   Since this is a age problem that perfect square has to be between 1 and 100. I've try every factor of number between 1 and 100 inclusive, and found none that matches.  Can there be another way besides trial and error?


Suppose $a, b \in \mathbb{Z}$, $a > b$, and $\gcd (a,b) = 1$.  What can be said about $\gcd (a+b,a-b)$?  Is it true in general that $\gcd (a+b,a-b) \leq 2$?

I want to show that for $\gcd(a,b) = 1$ $a,b \in Z$   $\gcd(a+b, a-b) = 1$ or $\gcd(a+b, a-b) = 2$ holds.      I think the first step should look something like this:      $d = \gcd(a+b, a-b) = \gcd(2a, a-b)$   From here I tried to proceed with two cases. 1: $a-b$ is even, which leads to $\gcd(a+b, a-b) = 2$ 2: $a-b$ is odd, which leads to $\gcd(a+b, a-b) = 1$  My main problem I think is, that I do not know how I should include $\gcd(a,b) = 1$ in the proof.  Any help is appreciated. Thx in advance. Cherio Woltan


We want to restore 2012 *.bak to 2008 sql server, we don't want to prefer import/export logical backup.  Looking forward to know downgrade procedure.

When trying to restore a backup to a SQL Server Express 2008 database I got the following error:  Restore failed for Server '...\SQLEXPRESS'.  (Microsoft.SqlServer.SmoExtended) System.Data.SqlClient.SqlError: The database was backed up on a server running version 10.50.1600.  That version is incompatible with this server, which is running version 10.00.2531.  Either restore the database on a server that supports the backup, or use a backup  that is compatible with this server. (Microsoft.SqlServer.Smo)   Is there a way to get a backup which is compatible with the older (in my case 10.00.2531) version from the newer (in my case 10.50.1600) version of SQL Server Express?


Suppose we have $n+1$ people in a circle ${0,1,2,3....n}$, we pass around a broccoli stick. The person $k$ has probability $p$ to pass the stick to $k+1$ and probability $q = 1-p$ to pass it to the $k-1$ person. And $p>0.5>q$.   NOTE: THIS IS NOT A SYMMETRIC WALK!   One wins if he is the last person remaining that has not touched the stick.  Where should a person situate to get the best possibility of winning?  I Want to calculate P(person i-1) gets the stick, passes it to i+1 without going through i. And P(person i+1) gets stick, passes it to i-1 without going through i, then condition.

$n$ cats form a circle, indexed from $0$ to $n-1$. At first, there is a ball at the cat $0$. We throw a coin with the probability of $p$ heads up. If the coin is heads up, we pass the ball clockwise, otherwise counter clockwise. We repeat this until all cats have touched the ball. What is the probability of the ball finally at the cat $k$?


I want to upgrade the 500GB HDD that came with my Dell Laptop to a 120GB SSD. Windows 8 came pre-loaded (OEM, no sticker).  Here's what I've tried so far:  Attempt #1:  Create a restore disk using the supplied Microsoft and Dell utilities.  FAILED: The installer will not allow me to restore to a smaller disk.  Attempt #2:  Create a bootable USB installer using an existing install of Windows 7 on another machine using the installer from: .  FAILED:  On the target computer: The installer fails saying there's no available image and to change the product key, however, I'm not given the option to do so, and the computer didn't come with a product key sticker.  On the computer creating the USB stick: The downloader never prompts me for a product key and instead applies the product key for a copy of Windows 8 Pro that I also downloaded on that computer (for another computer, NON-OEM).    How do you do a fresh install? This should not involve virtual machines or cloning disks. This computer shipped with Window 8 and there should be a way to legally install it.

Is there a good tool/program that allows me to clone a system drive to another, smaller hard drive?  I've bought a new 64GB SSD drive and would like to move my current Windows 7 Professional 64-bit installation to that new drive. My current drive is a 200GB SATA drive with one partition only. Of course there's enough free space to shrink my current partition to less than 64GB.


I know that the kinetic energy of a system is NOT conserved in a non-elastic collision. But energy is supposed to be conserved, so where does all that energy go? Is it transformed into other forms like heat and sound?

Why is there conservation of kinetic energy in  and not in ? What would be the difference that lead to conservation of kinetic energy in elastic collision and not in inelastic collision? We also know that mechanical energy is not converted to heat, light, sound etc. in elastic collision but converted to heat, light, sound etc. in inelastic collision. Why is mechanical energy converted as total energy is conserved in inelastic collision?


hello second question xD  as i said earlier i have a netbook and was looking thru persistent live usb making and all guides seem to need that i boot from live cd but my netbook doesn't have an optical drive :/ so here's my question(sorry if it has been asked before) can i make a persistent ubuntu live usb using my netbook? what i'm trying to achieve here is getting a 32gb usb drive and have my own portable computer here (ubuntu takes about 2gb so 30gb left for all my other files "music,video,documents,additional packages,etc." can i do that? as far as i could find the maximum persistent storage i could have is 4gb which is a real waste for a 32gb drive :/ thanks for all the help :) best regards, Raif Felemban (aka ubunoob) :P

If you are hurrying to reply, System → Administration → StartUp Disk Creator -- no, that's not what I'm talking about.   I want to try Ubuntu 11.04's Unity without touching my existing Ubuntu install.  To do this, I need to install the nVidia drivers first (sigh).  To do this, I need changes to persist a reboot.  To do this, I need to really install Ubuntu on a USB key.  How do you do that?    What I tried   I tried to make a USB key from , then boot from it, then choose "Install Ubuntu." The installer refused to install to the installation media itself. I tried, from my installed copy of Ubuntu:  sudo kvm /dev/sdb --cdrom .cache/testdrive/iso/ubuntu_natty-desktop-i386.iso   ...but the installer didn't detect the disk properly.


What is the correct way to express "null T", which represents the nullspace of a linear map T?  I've been doing \newcommand{\nullspace}{\text{null }} which is a hack, but I want there to be a space between "null" and "T".  One problem with my approach is that the "null" is italic when it's written within a theorem etc, but in a standard express it's not italic. I would prefer it to always be non-italic.

Mathematical operators, such as function names, should be set in roman type, not italics. Latex already has commands for some operators, including \max, \min, and \log.  How can I define additional such commands?


Calculate $\lim_{x\to\infty} (\sin\frac{1}{x}+\cos\frac{1}{x})^x$  without using l'Hopital's rule.   I attempted pulling something out to get a limit that resembles $e$, this gave me:  $$\sin^x\frac{1}{x}(1+\frac{1}{\tan\frac{1}{x}})^x=\sin^x\frac{1}{x}\bigg[(1+\frac{1}{\tan\frac{1}{x}})^{\tan\frac{1}{x}}\bigg]^{\frac{x}{\tan\frac{1}{x}}}$$  But then the first part goes to $0$ and the exponent goes to infinity, and I'm kinda stumped.

$$\lim_{x\to\infty}\left(\sin{\frac 1x}+\cos{\frac 1x}\right)^x$$  It is about the $(\to1)^{(\to\infty)}$ situation. Can we find its limit using the formula $\lim_{x\to\infty}(1+\frac 1x)^x=e$? If yes, then how?


I am getting this run time error which says there is a null pointer exception. I am just a beginner at Java and don't understand what this means. Error message is as follows:  Exception in thread "main" java.lang.NullPointerException at MyLongArray.insert(MyLongArray.java:26) at MyLongArray.main(MyLongArray.java:69)  import java.util.*;  public class MyLongArray {     private long a[];     private int nElems;          public MyLongArray(int size)     {                  long[] a = new long[size];                  nElems = a.length;     }     public int find(long searchKey) {         int m =0;         for(int i=0; i < nElems; i++)             if(searchKey == a[i])                 m = i;         return m;     }     public void insert(long value) {         @SuppressWarnings("resource")         Scanner  sc = new Scanner(System.in);         System.out.print("At what index do you want to insert? "); int i = sc.nextInt();             a[i] = value;              }     public long getElem(int index) {         return a[index];     }     public boolean delete(long value) {         long[] temp = new long[nElems];         int f = 0;         int o = 0;         for(int i=0; i < nElems; i++)         {             if(value != a[i])             {                 temp[o++] = a[i];             }             else                 f = 1;                          }                  for(int j=0; j < nElems; j++)             a[j] = temp[j];                  for(int i=0; i < nElems; i++)             System.out.print(a[i] + " ");                  if (f==1)             return true;         else             return false;                  }     public void display()      {         for(int i =0; i < nElems; i++)             System.out.print(a[i] + " ");     }           public static void main(String[] args)     {         MyLongArray m = new MyLongArray(5);         m.insert(5);         m.find(21);         m.getElem(2);         m.delete(3);         m.display();          }         }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


How do i do this in Ubuntu 19.4 ? Is there an application or command I can do  Looked around but no luck  Update: Found it by using " dmidecode -t 2 " ()

Is there a way to find what motherboard model I have?  If yes, how, please?


Has anyone done any user testing they could share about padlock or shield icons on payments screens and which is perceived as most secure?

Should I show some sort of "this site is secure" puffery (e.g. lock image, or some brief "this site is secure" boilerplate) on my credit card payment screen? If so, what should it look like? If not, why not?  I do want my customers to feel confident (as well as actually be safe) if they choose to enter their credit card details to pay my clients. I also want them to learn a healthy cynicism. Most of my customers are likely to have a very low level of technical knowledge about internet security and are usually either too trusting, and (in some cases) too suspicious of the wrong things.  I even had a customer call me up saying he wasn't sure if my payment page was secure because it didn't have any "padlock" image within the page. (yes, the page had a valid SSL certificate, the customer had the correct URL, and his version of Chrome was showing it with the green padlock with the "Secure" label at the time - after pointing this out he was happy to proceed).  I just feel it's a bit strange to splash a "this is secure" badge on a page because I know it means nothing, technically - because a phishing page would just as easily show the exact same badge.  Assumption: that my site is actually secure (let's just say I've tried my best and will continue to improve as much as possible).  For reference, here is the page as it currently stands:    Here's a mockup of what I mean:    UPDATE after some modifications:


I have a post carousel where i am showing archive post .

                                                      Ahmedabad Investor CampFinal Disscusion
29 may 2019

   and CSS  .post__title, .post:link, .post:visited {      font-size: 18px;      font-weight: 500;      color: #fff;      cursor: pointer;      display: block; }  .post__img {      position: relative; }  .post__img::before {      content: "";      display: block;      height: 100%;      position: absolute;      top: 0;      left: 0;      width: 100%;      background-color: rgba(255, 255, 255, .8); }  .post__date {      font-size: 12px;      font-weight: 400;      color: white; }  .post--small {      display: flex; }  .post--small .post__img {      width: 119px; }   I am trying to achieve overlay on images with any extra div , so i used ::before element . I think everything i done is right but this code didn't work .   Please help , Thank you in advance

I want to overlay one image with another using CSS. An example of this is the first image (the background if you like) will be a thumbnail link of a product, with the link opening a lightbox / popup showing a larger version of the image.   On top of this linked image I would like an image of a magnifying glass, to show people that the image can be clicked to enlarge it (apparently this isn't obvious without the magnifying glass).


I've been up to Blender since mid 2016, started to work professionaly selling my 3D models since Jan, 2018... and now I'm used to hear the same questions from the customers: "Are your models game-ready?"  And I always reply: "By the moment all my models published are not 100% optimized for games"  I say this because I do use PBR materials, modelled mid-poly with tris, and now I'm learning to get my new models rigged and ready to animate. But I think something is missing.  The principal question is... what it takes to make a model game-ready?  do I have to use Blender Game Engine to achieve this? In college, they taught me how to use Cycles only, and I don't know if a model with mid-poly tris, PBR materials and properly rigged for animations makes it "game-ready" altough it was made entirely in Cycles engine.  a "game-ready" model bought from a digital store, makes it ok for commercial licencing? this is a polemic question, but some customers ask this in some situations. For example: imagine that I make a 3D game-ready model of a Fender Stratocaster guitar, and sell it on internet via a third-parties 3D gallery. That model can make it into an actual published lucrative videogame using the brands and models I've made?  Thanks in advance for your support.

Recently, I am trying to create 3D models for my own game project. However, when I do some researches on game models, I come up with the term - game-ready models and I could not find any clear definition online. Could anyone tell me about what exactly is game-ready models and how to know if my 3D models (created by Blender mainly) is suitable for games.  From what I know by far, quad topology is preferred in Blender. However, for most of the game engine, triangle topology is preferred (Please correct me if I am wrong). Does it mean I have to manually change the models in Blender from quad topology to triangle topology before importing to the game engine?  Thanks for any helps.


There are $100$ cakes for lunch at $1$pm. One of them is poisoned. The poison takes exactly $1$ hour to kill the person who ate it. But still, some people have to taste it (just through a small piece) to make sure the lunch can be held safely. It is now $11$:$30$am. What is the minimum amount of people that have to risk their lives?   I have no idea what the answer is. Someone can eat multiple cakes so I know the answer is not 100.   By the way, can someone change the tags? I actually don't know what tag(s) it belongs to.

You are a pie maker and you are holding a fair to display your pies. You have 1000 pies. You have 10 workers to help you. The fair is in two hours. Unfortunately you discover that a rival pie maker has poisoned one of your pies with a form of norovirus that makes people violently ill one and a half hours after even consuming a tiny bit of it. You know if any single person who visits your fair gets ill, your business will collapse but you need all the non poisoned pies for the fair. You can take small samples from the pies without spoiling them and your workers are prepared to do anything to help you. How do you find the poisoned pie?


Could someone please explain to me the purpose of the following piece of code?  <?php print theme('links__system_secondary_menu', array(   'links' => $secondary_menu,   'attributes' => array(     'id' => 'secondary-menu',     'class' => array('links', 'inline', 'clearfix'),   ),   'heading' => array(     'text' => $secondary_menu_heading,     'level' => 'h2',     'class' => array('element-invisible'),   ), )); ?>   I have researched for quite some time and could not find an answer to it. It would seem this is in all Drupal7 themes and if removed, the "My account" and "Log out" links disappear.

I searched for links__system_main_menu, but just find usages of this theme. Where is it defined?


In an article at the "Gravity Probe B" website,  the following statement is included: "... the gravitational field carries energy and thus "attracts itself"; ..." What does it mean? Edit: I was made aware of the following question:  . The answers given there are related, indeed. However, I would be grateful if the explanation of 'self-interaction', in general is extended to the specific meaning of 'self-attraction' of the gravitational field.

Today, someone asked me why "the warped space-time warps itself" (he read it in ). I guess this is related to the gravitational self-interaction. But I don't really understand the gravitational self-interaction. Why the curvature in general relativity influences itself?