I have created my own test JSON and try to incorporate it into my Android app using Retrofit but for some reason I can´t seem to understand I get a Null Point Exception when trying to fetch the JSON.   I have created JSON that looks something like this:  [{"date":"2019/01/01","availability":"available"},{"date":"2019/01/02","availability":"closed"},{"date":"2019/01/03","availability":"closed"}]   And so on...  Then I have set up both the Retrofit code and the Room database code.  Here is the Retrofit code from the main class:  public class MainActivity extends AppCompatActivity {  MainRepository mainRepository; Call<List<RFVariables>> getRFPosts;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate( savedInstanceState );     setContentView( R.layout.activity_main );      getRFPosts = mainRepository.getGetPosts();      getRFPosts.enqueue( new Callback<List<RFVariables>>() {         @Override         public void onResponse(Call<List<RFVariables>> call, Response<List<RFVariables>> response) {             List<RFVariables> myResponse = response.body();              if(myResponse != null) {                 for(RFVariables item: myResponse) {                     Log.d("TAG", item.getDate());                  }             }          }          @Override         public void onFailure(Call<List<RFVariables>> call, Throwable t) {          }     } );   It crashes on the getRFPosts = mainRepository.getGetPosts(); line with the error Attempt to invoke interface method 'void retrofit2.Call.enqueue(retrofit2.Callback)' on a null object reference         at com.slothmode.sunnyatsea.MainActivity.onCreate(MainActivity.java:25)  The repository code looks like this:  private Retrofit retrofitObject; private RFCalls retrofitRepository; private Call<List<RFVariables>> getPosts;  public MainRepository(Application application) {     this.retrofitObject = new Retrofit.Builder()             .baseUrl( "https://api.myjson.com/bins/" )             .addConverterFactory( GsonConverterFactory.create() )             .build();      this.retrofitRepository = this.retrofitObject.create( RFCalls.class );     this.getPosts = this.retrofitRepository.findPosts(); }  public Call<List<RFVariables>> getGetPosts() {     return getPosts; }   I have done this successfully before, so not sure what's mising this time around. Seems like an exact replica of my other successful projects. What am I missing? Let me know if there is more code I should show. Thanks in advance. Really stuck here.

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?


Are there any tools or methods that allow QGIS analyze whether the lots/parcels have been untouched or developed, and return a "1" or "0" to a table or points layer or anything?  I was thinking more into simple shape recognition, like a driveway(2 parallel lines) or a rectangle (dwelling of sorts) or by colors: green/brownish(untouched), silver-ish (developed,) or by a differential of "most of area in one color" and a spot with a "different color". The lots-layer has an attribute table with areas, id, etc. and overlaid with Google Maps/Bing, etc. (see attached pic)

From  page:  Change detection for GIS (geographical information systems) is a process that measures how the attributes of a particular area have changed between two or more time periods. Change detection often involves comparing aerial photographs or satellite imagery of the area taken at different times. The process is most frequently associated with environmental monitoring, natural resource management, or measuring urban development  How is the comparison done? With what tools? I feel that the description is not complete. Or something is missing. Where or in which books can I find more information about Change Detection? What tools should I use to perform such an analysis using the data in a shapefile? (only open-source please)  Some papers on change detection (theory and techniques)  Trend change detection in NDVI time series: Effects of inter-annual variability and methodology Forkel, M. , Carvalhais, N. , Verbesselt, J. , Mahecha, M.D. , Neigh, C. , Reichstein, M. (2013) Remote Sensing 5 (2013)5. - ISSN 2072-4292 - p. 2113 - 2144. Shifts in global vegetation activity trends Jong, R. de , Verbesselt, J. , Zeileis, A. , Schaepman, M.E. (2013) Remote Sensing 5 (2013)3. - ISSN 2072-4292 - p. 1117 - 1133. Relationships between declining summer sea ice, increasing temperatures and changing vegetation in the Siberian Arctic tundra from MODIS time series (2000–11) Dutrieux, L.P. , Bartholomeus, H.M. , Herold, M. , Verbesselt, J. (2012) Environmental Research Letters 7 (2012)4. - ISSN 1748-9326 - p. 12. Near real-time disturbance detection using satellite image time series Verbesselt, J.P. , Zeileis, A. , Herold, M. (2012) Remote Sensing of Environment 123 (2012). - ISSN 0034-4257 - p. 98 - 108. Trend changes in global greening and browning: Contribution of short-term trends to longer-term change Jong, R. de , Verbesselt, J. , Schaepman, M.E. , Bruin, S. de (2012) Global Change Biology 18 (2012)2. - ISSN 1354-1013 - p. 642 - 655. Phenological change detection while accounting for abrupt and gradual trends in satellite image time series Verbesselt, J. , Hyndman, R. , Zeileis, A. , Culvenor, D. (2010) Remote Sensing of Environment 114 (2010)12. - ISSN 0034-4257 - p. 2970 - 2980. Detecting trend and seasonal changes in satellite image time series Verbesselt, J. , Hyndman, R. , Newnham, G. , Culvenor, D. (2010) Remote Sensing of Environment 114 (2010)1. - ISSN 0034-4257 - p. 106 - 115. (I'll add more in the future as If I discover more notable  papers)


for example, I want to print 01234567 so I know I need to write  for i in range(8)  print(i),   and it will print 0 1 2 3 4 5 6 7 instead of change the line for every number but I want it whithout spaces

I'd like to do it in Python. What I'd like to do in this example in C: #include <stdio.h>  int main() {     int i;     for (i=0; i<10; i++) printf(".");     return 0; }  Output: ..........  In Python: >>> for i in range(10): print('.') . . . . . . . . . . >>> print('.', '.', '.', '.', '.', '.', '.', '.', '.', '.') . . . . . . . . . .  In Python print will add a \n or space, how can I avoid that? Now, it's just an example, don't tell me I can first build a string then print it. I'd like to know how to "append" strings to stdout.


So after hunting around the various review sites and message boards, I still have one question about this game:  Aside from the updated graphics, is there anything new in this version of the game?  I've played the Wii version, as well as the Okamiden game for the DS.

Okami is now reborn in High Definition for PS3. The graphics are obviously better, sharper and yet preserves the gist of the original game, however I can swear some of the texts have changed as well.  My PS2 console is no longer available to me so I can't test it myself, but does anyone know whether there are any changes to the game (aside from graphics) or not?


I am getting a Null Pointer Exception. And i have used the long text data type in the ms access table to for date and description      try          {          int z1=1,z2=2;              String s=JOptionPane.showInputDialog("enter the date(DD/MM/YEAR)");          String s1=JOptionPane.showInputDialog("enter data into your dairy");          pstmt=conn.prepareStatement(" INSERT  INTO  Table2(date,description) values(?,?)");          pstmt.setString(z1, s);          pstmt.setString(z2, s1);          pstmt.executeUpdate();          JOptionPane.showMessageDialog(null, "Data enterd successfully");          update1();          close();          }           catch(Exception e1)          {              JOptionPane.showMessageDialog(null, "Data Insertion failed.This date may already exist or may be some other error");              JOptionPane.showMessageDialog(null, "ERROR:"+e1.getMessage());           }   I have used data type long text for date and description in the ms access table.


I am inserting a Figure named Figure1 inside a document in TexMaker using the code below:  \begin{figure} \begin{center} \begin{tabular}{|c|}\hline \ \hspace{10cm}\ \\ \\ \includegraphics[width=5in]{Figure1}\\ \\ \\ \hline \end{tabular} \end{center} \caption{Shows that the number of patients}         \label{f:pic} \end{figure}   However, this image is floating in the text that is before it. How can I force it to be displayed after a particular paragraph and before another paragraph?

Is there any package or a method to force LaTeX to keep floating environments like table and figure closer to where they are declared?


Using induction, I have to prove that for any $n \in \mathbb{N}^*$ the following is true:  $$2^{2^n} + 3^{2^n} + 5^{2^n} \equiv 0 \pmod{19}$$  I've never done modular arithmetic before, but after reading online a bit I understood that the above notation means that when we divide the $2$ terms to the left and to the right of the $\equiv$ symbol, we get the same remainder. So that means that since the right term is $0$ $\Rightarrow$ the left term is a multiple of $19$. So we have:  $$2^{2^n} + 3^{2^n} + 5^{2^n} = 19a$$  with $a \in \mathbb{N}^*$. The base case is obvious:  $$p(1): 2^2 + 3^2 + 5 ^ 2 = 38 = 2 \cdot 19$$  so $p(1)$ is evidently true. I have problems with the induction step. Let's assume $p(k)$ true, so we have:  $$p(k):2^{2^k} + 3^{2^k} + 5^{2^k} = 19a$$  for some $a \in \mathbb{N}^*$. So now we have to show that:  $$p(k+1) : 2^{2^{k+1}} + 3^{2^{k+1}} + 5^{2^{k+1}}$$  is also a multiple of $19$. I have problems with this. I tried squaring what I got at $p(k)$ since that would get me the terms that I want:  $$\hspace{6.7cm} 2^{2^k} + 3^{2^k} + 5^{2^k} = 19a \hspace{6cm} ()^2$$  $$2^{2^{k+1}} + 3^{2^{k+1}} + 5^{2^{k+1}} + 2 \cdot 2^{2^k} \cdot 3^{2^k} + 2 \cdot 2^{2^k} \cdot 5^{2^k} + 2 \cdot 3^{2^k} \cdot 5^{2^k} = 361a^2$$  $$2^{2^{k+1}} + 3^{2^{k+1}} + 5^{2^{k+1}} + 2 (6^{2^k} + 10^{2^k} + 15^{2^k}) = 361 a^2$$  $$2^{2^{k+1}} + 3^{2^{k+1}} + 5^{2^{k+1}} = 361 a^2 - 2 (6^{2^k} + 10^{2^k} + 15^{2^k})$$  Since $361$ is a multiple of $19$, in order to show that the left-hand side is a multiple of $19$ I would have to show that $6^{2^k} + 10^{2^k} + 15^{2^k}$ is also a multiple of $19$, so I just exchanged a problem I couldn't solve for another problem I can't solve.  How should I approach this?

I came across the following in the book Handbook of Mathematical Induction: $$ 19\mid (2^{2^n}+3^{2^n}+5^{2^n}),\quad n\in\mathbb{Z^+}\tag{1} $$ Apparently, this problem is not so bad if you think about it in a somewhat "outside of the box" sort of way, but it is supposed to be quite challenging otherwise.   Question: How might one prove $(1)$ using induction or otherwise? The "outside of the box" answer has been provided but with details oranged out so as not to spoil it for anyone who may come up with that solution individually.


Can my machine with dual intel core i5 1.80GHz, x64 processor and 4 Gb ram, run the newest Ubuntu 20.04? I know that on their official pages is written as the minimal requirements at least 2 GHz, but it seems to me that diffence between 1.8 and 2 isn't too much, but I am not expert. Thank you for your time and answer kind people

I have a device on which I would like to install Ubuntu. How do I find out if Ubuntu will work on it?


I have an editable div in which users write text for comment. Now I want to remove space before and after the text. For example when a user type   "&nbsp;&nbsp;Hello&nbsp;world&nbsp;&nbsp;&nbsp;"   I have to insert   "Hello&nbsp;world"    into the database.  I have tried   text.trim()   but it doesn't work. How can I do this ?  Also how to remove duplicates empty line ?  I would like to replace
Hello

World
   By
Hello

World
   Thank you

How do I trim a string in JavaScript? That is, how do I remove all whitespace from the beginning and the end of the string in JavaScript?


Some of the packages of CTAN are really good but not discovered by many. I recently encountered one of the good ones, namely latexindent, and I thought that would be great if everyone introduces the best he/she is aware of. So,   Kindly please introduce what you found useful in CTAN that should be recommended to others.

I'm getting the impression from reading the answers written by some of the real experts here that there are quite a few little packages that just tweak LaTeX2e's default behaviour a little to make it more sensible here and there.  Rather than try to pick these up one by one as I read answers to questions (and thus risk missing them), I thought I'd ask up front what LaTeX2e packages people load by default in (almost) every document.  As this is a "big list" question, I'm making it CW.  I don't know if there are standard rules across all SE/SO sites for such questions, but on MathOverflow the rule is generally: one thing (in this case, package) per answer.  I guess that if a couple of packages really do go together then it would be fine to group them.  This is perhaps a little subjective and a little close to the line, so I'll not be offended if it gets closed or voted down!  (But please explain why in the comments.)  Also see our community poll question:


I've got 16.10 installed on a HP laptop for just a couple days now.  Yesterday, I had to do some re-configuring to my house Wifi system, and oddly now, when the laptop boots it does not auto-connect the wifi.  The box is checked to do that, and indeed if I click the drop box, it connects.  So why not the auto-connect?  What did I break?  WiFi: rtl8723be

I have dual booted my Windows 8 laptop with Ubuntu 14.04. The wifi driver is Realtek rtl8723be. It didn't use to work but I updated the kernel to 3.18 and reinstalled the driver and that seemed to solve the problem for a few hours. Then it would be connected for around 30 minutes and then the connection would stop, even though the icon on the system tray would still indicate it's connected. The only thing that works is restarting the computer but then, again, after 30 minutes the connection stops.


struct test{     int year;     char text;     double num; };  int main () {   test t;  cout<<sizeof(t);   return 0; }   The result is 16, while I was expecting 13. Since sizeof(char) is 1. What am I missing here?

Why does the sizeof operator return a size larger for a structure than the total sizes of the structure's members?


I'm using Plex Media Manager under Ubuntu 14.04 and want to playback HEVC videos on my LG 42LN5708 television via Plex.  HEVC videos play just fine in Mozilla Firefox when I open the Plex Media Manager program there. So apparently Plex understands what the format is. However, when I try to play the same video on my LG 42LN5708 television it says the format is not supported.  How is this possible? Plex Media Manager is just a frame server, right? So why does it not serve the frames properly to the television?

I've installed Plex Media Server in my Raspberry Pi 3. It works perfect but it doesn't have enough CPU power to transcode (when it tries the video freezes every two or three seconds). One of my Plex clients is an LG TV and I find Plex Server transcoding files very often when I try to watch it from the TV.  I took one file as an example. It is a .mov file, the video is 1080p—HEVC and the audio AAC 5.1. I copied the file in a pen drive and the TV played it without any problems. I've also played it from Plex's DLNA server and I could watch it perfectly. However when I try to watch it through the Plex App in the TV the server shows:     Trasnscoding      Video Transcoding HEVC to H264      Audio Direct stream   In the TV I've enabled the options Direct Play and Direct Stream and I've all qualities set to Original.  Am I missing some reason that can make Plex transcode the file or is there something wrong?


I'm an art student and I'm working on a stop motion short video that I'm making and it would help a lot if a ghost like view of my previous frame that i took to show on the lcd of my camera when I'm taking the next frame on top of the live view , so i can change the composition with having the previous frame and live view at the same time. i want to know if there is such a feature for sony a7rii camera or what camera has such feature. thanks.

I am looking for a way to make stop video - but this is really a photography question.  I am looking for a way to:   Shoot 1st photograph When I prepare second, see the 1st with alpha/transparency to correctly fit things This actually needs to work in all photos and needs to be in live view (just simple shoot 2 photos and fit them in photoshop took too much time)   Something like this:    For now I have 3 cameras: Canon 1100D, Canon 600D and Canon 60D - so I actually think that is possible at least in 60D - could be a Canon firmware or even a computer (OSX/Win) software.


Find all even natural numbers $n$ such that the following is true:   There is a non-constant function $f : \Bbb{R}^2 \longrightarrow \Bbb{Z}_2$ such that for any regular $n$-gon $A_1...A_n$, $f(A_1) + \cdots + f(A_n) =0$.   NOTE: This is the unsolved part of   problem. I chose to state it in a separate question first to get more attention and second since some people may want to put a bounty on this part.

(This is adapted from problem $1$ of Putnam $2009$)  Find all values of $n$ such that the following is true:   There is a non-constant function $f : \Bbb{R}^2 \longrightarrow \Bbb{Z}_2$ such that for any regular $n$-gon $A_1...A_n$, $f(A_1) + \cdots + f(A_n) =0$.


Currently I am using a regular expression for validating numeric-only phone numbers which looks something like this:  /^([\d \-\)\(\+\.]{10,16})$/   I have a requirement where I need to upgrade the regular expression to support the below valid cases of phone numbers:  (866) 999-EMAS 1-800-MY-APPLE   Thanks

I'm trying to put together a comprehensive regex to validate phone numbers. Ideally it would handle international formats, but it must handle US formats, including the following:   1-234-567-8901 1-234-567-8901 x1234 1-234-567-8901 ext1234 1 (234) 567-8901 1.234.567.8901 1/234/567/8901 12345678901   I'll answer with my current attempt, but I'm hoping somebody has something better and/or more elegant.


I have a png logo-label I want applied to a section of the display. Problem is when I set up the label material and apply it the background of the display goes transparent too.

I'm trying to setup a image decal in cycles, and I can't figure how to setup the nodes to work fine. Does anyone know the solution?


I'm trying to get a path from user input and use it as a variable in a command:  read -e -p "Path to backup: " path mongodump --host localhost --port 27017 --db my-db --out $path   When I put there ~/here as a script variable command is never successful (no error). When I put the exactly same value the command directly it is working:  read -e -p "Path to backup: " path mongodump --host localhost --port 27017 --db my-db --out ~/here   When I print echo "$path" it prints ~/here.  Any ideas?  Thanks

I need to copy /root/nbu/file1.sh to every user's home directory if user's id is even number.  Trying to execute following script:  #!/bin/bash cat /etc/passwd | while read LINE do     username=$(awk -v var="$LINE" -F: '{         if ($3 % 2 == 0)            print $1         }')     cp /root/nbu/file1.sh ~"$username" done   And it does nothing. If I echo cp /root/nbu/file1.sh ~"$username" command and execute it directly in the script, it works.  I guess the problem is that ~ gets expanded in the bash script, but can't figure out how to solve this problem.  Thank you in advance.


I'm trying to create a pivot table to count the number of events a person has attended. In the example below, I'd like to remove the duplicates associated with a specific person.   Joyce is listed correctly, but Sharon is listed as having attended Event 1, two times. In the pivot table, this will give her count of attending two events, when in reality she would be getting credit for attending Event 1, twice.  Same goes for Jim, he is listed attending Conference 1 and Conference 2, twice.    How do I remove the duplicates associated with an individual and not have duplicates removed from the column entirely (only 1 Conference 1 can be listed). I tried highlighting Name and Event, Remove Duplicates, and it seemed to work for some of the data, but something like 3,000 rows were left without a full name of an event listing next to them.  Any help would be greatly appreciated!   Excel Table:

I am using Excel 2007.  I have more than 40000 records in Sheet1.  I want to remove the duplicates.  Constraint for duplicate would be if you have the exact same fields for the entire line. This means that every line must be different.  What would happen if Remove duplicates with respect to all columns?


Thank you for your support. I wish to make a bash script that uses the latest text copied and currently in clipboard.

In Windows I used command-line clipboard copy-and-paste utilities...      pclip.exe and gclip.exe     These were UnixUtils ports for Windows (but they only handled plain text). There were a couple of other native Windows utilities which could write/extract any format.    I've looked for something similar in Synaptic Package Manager, but I can't find anything.    Is there something there, that I've missed? ... or maybe this is available in Bash scripting?    The type of utility I'd like will be able to read/write via std-in/std-out or file-in/file-out, and handle Unicode, Rich Text Format, picture, etc. clipboard formats...    NB: I'm not after a clipboard manager.


Why is the friction static while driving a car (at constant speed) on a horizontal circular road? Please explain in details.

When a ball moves to the right, friction acts to oppose the motion, in other words, to the left. However, when a car travels around a bend, the friction acts in the perpendicular direction to the car's velocity and provides the centripetal force. I just cannot understand why friction would act in that direction.


I have a secret message which I want to encrypt such that any of several different keys can open it independently.  The keys can't know about each other and it has to be able to work completely locally without a network. In short I want two functions   encrypt(message, key1, key2, key3, ...) -> code decrypt(code, keyX) -> message                   for keyX in (key1, key2, key3...) decrypt(code, keyY) -> random                    for keyY not (key1, key2, key3...)   Ideally these functions would also have the property that  encrypt(message, key1) -> code1   decrypt(code1, key1) -> message encrypt(code1, key2) -> code2     decrypt(code2, key1) -> message, decrypt(code2, key2) -> message   This seems like it should be relatively possible to do but I can't figure out how to do it yet. In my research I came across similar problems which many people were calling broadcast encryption but when I read up on it, it seems like for most broadcast encryption schemes require that you broadcast some information about what set of people are allowed to unlock the content and this is used by everyone to calculate their new keys.  This isn't want I want. I need that the "locks" can't change and that adding a new lock doesn't invalidate the old ones.  A physical metaphor would be if you were locking a box lid to bottom using some number of padlocks.  The system I am looking for would be like a chain of padlocks so that opening any of them separates the top from the bottom of the box.  Furthermore, if you add another new padlock on the end of the chain somehow, any of the original keys are still just as useful at opening the whole box.  Anyone have some ideas or links to read up on? Thanks.

Is it possible to encrypt a message in such a way that multiple keys can independently decrypt it?  In other words:  Having knowledge of $key_1, key_2 ...key_N$, which are different symmetrical keys, is it possible to generate a ciphertext that can be independently decrypted using either $key_1$ or $key_2$ or $key_N$, in such a way that the length of the ciphertext is less than directly proportional to $N$?


My wife and I are applying to US universities for master's and PhD programmes. We both have a electrical engg. degree and are applying to the same department. However we would like to get into the same university. Is it possible to mention this in the application? Do universities take this into consideration when making admission decisions?

My significant other and I finish our master degrees at the same time and thus we are applying for PhD programmes at the same time. One major factor of accepting a potential offer would be if we could study at the same university, so I feel that mentioning a two-body problem would be advantageous for both, us and the admission committee. But where do I mention this? Is a line in the statement of purpose suitable here?     If you admit me, please also consider admitting my significant other Jane Roe.   Some additional information: We both do research in computer science. While I do research in natural language processing my partner does research in computer vision.


Recently a little insect crawled over the carpet. First I did not notice, as its appearance is quite similar to the coloring of the carpet. Then I understood that it is not a rolling crumble, as the window and the door were closed.  I took it on an ordinary sheet of DIN A4 paper, but have not the slightest idea, what kind of insect it is. It makes the impression to have taken a shower of water and dust in a row.  What's that insect called?   The second photo gives an idea of the size, as it shows a drinking glass turned upside down.  Note: The place this insect was encountered is in eastern Germany

I have found in a wooden house, in the mountains of central Spain this very curious insect:    I was wondering if that was its skin or whether it's decomposition or sand or saw-dust.  That particular region of Spain does have stink-bugs ... but this one doesn't look like anything I've seen before.  A google image search returns mostly arachnids ... but it seems to have only 6 legs.


Above is the input table. I am trying to bring all the childsku products in a single row with its count and its associated parent sku.But it is not working as expected           select [Parent SKU (PartNo) ],count([Child SKU]),[Child SKU]  from tbl_name        group by [Parent SKU (PartNo) ],[Child SKU]   Now I want the desired output to be like this:

I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).  In the original app, we used almost entirely ANSI-SQL compliant statements, with one significant exception -- we used MySQL's group_concat function fairly frequently.  group_concat, by the way, does this: given a table of, say, employee names and projects...  SELECT empName, projID FROM project_members;   returns:  ANDY   |  A100 ANDY   |  B391 ANDY   |  X010 TOM    |  A100 TOM    |  A510   ... and here's what you get with group_concat:  SELECT      empName, group_concat(projID SEPARATOR ' / ')  FROM      project_members  GROUP BY      empName;   returns:  ANDY   |  A100 / B391 / X010 TOM    |  A100 / A510   So what I'd like to know is: Is it possible to write, say, a user-defined function in SQL Server which emulates the functionality of group_concat?   I have almost no experience using UDFs, stored procedures, or anything like that, just straight-up SQL, so please err on the side of too much explanation :)


I have a table with images and text and I want to align them to the centre of the cells they're in. Most questions like this one have answers which first fix the cell size and then centre its contents.  How can I do this without having to fix the dimensions of the cell and just align contents of every cell to its centre (I'm specifically referring to vertical alignment since horizontal alignment is taken care of by |c|c|...)   \begin{table}[H]     \centering     \begin{tabular}{c|c|c|c|c}      \hline \includegraphics[height=1in]{IMG1.jpg} & 1 & 2 & 2 kHz & 1 kHz \\      \hline \includegraphics[height=1in]{IMG2.jpg} & 1 & 3 & 3 kHz & 1 kHz \\      \hline \includegraphics[height=1in]{IMG3.jpg} & 2 & 5 & 5 kHz & 2 kHz \\      \hline  \end{tabular} \caption{random caption}  \end{table}   This is what the code for my table looks like. The only problem is, in every cell, the image is vertically aligned to the top and the text is vertically aligned to the bottom. How can I fix this?

I want to create a table with multiple rows of the following form: a cell that contains text and then multiple cells that contain images. The text should be vertically centered and the contents of every column should also be centered horizontally. I am aware of the m{} column type but somehow this seems to fail if an image is contained in the row and determines the row height. Any ideas?  Minimal example:  \documentclass{article} \usepackage{graphicx} \usepackage{array} \begin{document} \begin{figure} \begin{tabular}{m{3cm}c} (a) & \includegraphics{some_picture.pdf}\\ \end{tabular} \end{figure}  \end{document}


There has been a consistent problem with downloading videos from youtube using youtube-dl.  The filename has random characters at the end.  e.g, original filename of the video is Scala Monads: Declutter Your Code With Monadic Design  but the filename of video after downloading is Monads - Declutter Your Code With Monadic Design-Mw_Jnn_Y5iA.f136.mp4  here is the warning during download:  WARNING: Requested formats are incompatible for merge and will be merged into mkv.   it will be really helpful if somebody could suggest a solution.

How the current file has been downloaded to display the original title? When i download always like P9pzm5b6Fxx.mp4, when the title is Tigerking.  How do I set it so that it is downloaded as tigerking.mp4?


So I have recently downloaded Kali Linux to research on Linux Operating systems and its distributions, and I have noticed that Kali Linux comes pre installed with many users apart from 'kali' and 'root', Why is this? Can we delete them? Or should I leave them there. This is the output of cat /etc/passwd:

The /etc/passwd is supposed to have a line for every user on the system. Amongst the common username and root there is a bunch of other users. Some examples:  timidity:x:114:127:TiMidity++ MIDI sequencer service:/etc/timidity:/bin/false liquidsoap:x:115:128::/usr/share/liquidsoap:/bin/false statd:x:116:65534::/var/lib/nfs:/bin/false gdm:x:117:131:Gnome Display Manager:/var/lib/gdm:/bin/false mysql:x:118:133:MySQL Server,,,:/nonexistent:/bin/false    What's the purpose with all these users? How can I login as mysql or gdm? What will the password be?


I know I can take a selfie with the built-in camera via the Photo Booth app. However, is there a way capture an image via command line, in sort of  style?

Is there a command line utility that allows me to take a picture from the built in camera?  Something like screencapture allows for, well, screen captures.  The reasoning for a command line tool is I would like for it to be stealthy, without a countdown or flash or other indication to the user that a picture is being taken.


so i get that when there is an excess of neutrons, neutron is converted into a proton. An electron is produced to neutralise the +1 charge of proton. But why is an anti neutrino produced?

Why do we need neutrino to explain neutron ? Is there any evidence regarding existence neutrinos in the context of $n\to p + e + \bar{\nu}_e$?


I just had a confusion. Does the mass of the body actually increase when it is moving with a certain velocity? Or does it only look like the mass has increase to another observer. How can the actual mass of the body increase. Please correct me if I am wrong but I feel that it only seems to the observer that the mass has increased but it does not increase in real.  The increase of actual mass would imply that that its velocity will decrease to comply with conservation of momentum. But how can the velocity decrease if no external force is applied?

I'm reading Nano: The Essentials by T. Pradeep and I came upon this statement in the section explaining the basics of scanning electron microscopy.     However, the equation breaks down when the electron velocity approaches the speed of light as mass increases. At such velocities, one needs to do relativistic correction to the mass so that it becomes[...]   We all know about the famous theory of relativity, but I couldn't quite grasp the "why" of its concepts yet. This might shed new light on what I already know about time slowing down for me if I move faster.  Why does the (relativistic) mass of an object increase when its speed approaches that of light?


Will Skyrim mods that are labeled for use with the Special Edition of Skyrim work with the original version, specifically the Legendary Edition, since it has all the content the special edition does?

I just figured out I had Skyrim in my Steam games. It's the 32-bit non-Legendary Edition Skyrim without any DLCs. Can I still use Legendary Edition mods on it?


Added: The Wilson reflection formula is natural tool but how to simplify for case $n = 4$ ? $2 [(p-3)!-\frac{(p-1)}{2}] = (p-3)!2! - (p-1) = (p-3)!2! +1 -p$. We see easily this satisfy $\mod p = 0$. Let's go: $(p-4)!3! - (p+1) = 6 [(p-4)!-\frac{(p+1)}{6}]$. Then, the new term should be $(p-4)!-\frac{(p+1)}{6}$. But $p+1$ is not always divisible by 6. The aim is to keep $(p-n)!$ free but is it unavoidable get rid of 3 in $(p-4)! 3 -\frac{(p+1)}{2}$ ? For example by subtractor $-k\frac{(p+1)}{2}$ ? -- original question Let $p$ be a prime and $p > n$ (sequencer) and for all the cases: $(p-n)!+1 \mod p = 0$, when $n=1$ $(p-n)!-1 \mod p = 0$, when $n=2$ $(p-n)!-\frac{(p-1)}{2} \mod p = 0$, when $n=3$ ... How to find the next step? Is $(p-n)!$ part based on $n=4$ or $n=5$ i.e. is it necessary for $n$ being a prime too?

Suppose that $p$ is a prime. Suppose further that $h$ and $k$ are non-negative integers such that $h + k = p − 1$.   I want to prove that $h!k! + (−1)^h \equiv 0 \pmod{p}$  My first thought is that by Wilson's theorem, $(p-1)! \equiv -1 \pmod{p}$, and $h!k!$ divides $(p-1)!$ (definition of a binomial). Where would I go from here?


This question has been asked before but answers didn't work that well for me. I am making a animation at 720p on Cycles i3-7 gen , NVidia Geforce 940mx, I have enabled both of them in CUDA. I am focused on something between quality and time My scene has  Volumetrics, disabled refractive caustics tile size is 256 X 256 light bounces set to around 4-5 volumetrics to 7 samples sampling to 100 enabled blender's optix denoiser and a simple composition node tree  Still it renders a single image in 15-20 minutes and my animation is around 430 frames. Any further ways to reduce render time? The image is of the scene render from EEVEE to give a idea what it looks like, the purple flame was removed

Edit:  Recently I've been rendering a fairly geometry dense indoor scene, with one window. I was finding that even at 524 render samples, the scene was grainy, and also really REALLY slow!   I had a portal over the window and my world resolution was at 2048 (supposed to decrease grain) I was rendering with 3 diffuse, 4 glossy, 8 Transmission, 0 volume and a total of 8 max bounces and 4 min.  The render time was around 7 minutes per frame (grainy) and increasing rendertime wouldn't have been an issue, provided this wasn't an animation. However, I remember a while back, on a "speed up cycles" vid, that AO bounces was mentioned?


I simply want to create a date that is 3 days from now for use in a typescript angular component.  I have looked at  but this seems only to relate to pipes. Although I did see  about using pipes in code, looks a bit hacky...  Maybe I'm missing something as this should be really simple?!  Thanks

How to add days to current Date using JavaScript. Does JavaScript have a built in function like .Net's AddDay?


Cyclic Group $Z_{n}$  How do I find all the Subgroups of $Z_{200}$ under additive modulo 200? And how many subgroups are there? I know the definition of subgroups but to find all the subgroups of such a large set is a bit difficult for me. Is there a smart way to find it?     The answer to this question is 12 and I not sure if this is correct.

Lemma $1.92$ in Rotman's textbook (Advanced Modern Algebra, second edition) states, Let $G = \langle a \rangle$ be a cyclic group. (i) Every subgroup $S$ of $G$ is cyclic. (ii) If $|G|=n$, then $G$ has a unique subgroup of order $d$ for each divisor $d$ of $n$.  I understand how every subgroup must be cyclic and that there must be a subgroup for each divisor of $d$. But how is that subgroup unique? I'm having trouble understanding this intuitively. For example, if we look at the cyclic subgroup $\Bbb{7}$, we know that there are $6$ elements of order $7$. So we have six different cyclic subgroups of order $7$, right? Thanks in advance.


I want to emphasize a certain part of a document by putting a box around it. Any help is much appreciated.

I am looking for something like \fbox but it seems that you cannot use it when a math environment is included. However its not only a math environment (then you could use \boxed I know) but also text, I need to be in a frame.  example:  \rdmframeboxaroundwhatever{  blablabla  \begin{align} Formula of the universe \end{align}   Hoaray  }


I check my credit score on Credit Karma every week just to make sure everything is ok. Every now and then the score goes up a point, sometimes based on utilization it goes down a point or so.  However, today I open it up and my score has dropped by 20 points! From 753 to 733 in a week. The "changes" section says it is because my balance went up on a credit card, to nearly 50% utilization, but I wouldn't think that is worth 20 points. Especially when it's only ~8% total credit card utilization.     Why would this change be so dramatic so quickly? I already paid the card off (as I do every month) should the score return to normal or will I have to fight for those 20 points one at a time again?  Edit: Roughly a month later (via CreditKarma) my score jumped the full 20 points back all at once. So it appears it was indeed a temporary jump.

I check my credit score monthly using a credit tracking app provided by my credit card company. I use a reminder to check on the same day each month, and have been tracking my credit score for almost two years.  In the last year, the app switched from a TransUnion model to VantageScore 3.0. I have TransUnion data for the entire duration, but only about a year's worth of VantageScore data.  I have good credit, and my TransUnion score has increased steadily from ~740 to ~780 in the last two years.  My VantageScore started around ~760 and increased to ~800 last month. This morning when I checked my credit score, it had dropped just over 50 points to ~750.  My TransUnion score has stayed solid at ~780.  My questions are:  Should I be concerned about this sudden change in score?  Is there any way I can determine what changed to account for the sudden change in credit score?


I have been dual booting Ubuntu and Windows 10 for quite a while now and noticed that after the most recent update in Ubuntu, I cannot access my Windows 10 partition from Grub anymore.  I have already reinstalled/repaired Grub and even updated it.  Does anyone have an idea how to go about this  Cheers,

I installed Windows on my computer, followed by an installation of Ubuntu. However, now I'm unable to boot into my Windows install.  What can I do to fix this?


can you please tell me if my proof is right or if I'm taking some steps for granted? Thanks  $$\forall a, b\in \Bbb R \Rightarrow (-a)b=-ab$$  $$(-a)b\cdot (-a)^{-1} = -ab\cdot (-a)^{-1} \\ 1\cdot b = \frac{-ab}{-a} \\ b=b $$

So I am studying for an exam and was wondering if anyone could explain some of the reasoning being the proofs of the following properties:   Let R be a ring with $a,b\in R$. Then    $a0=0a=0$  $a(-b)=(-a)b=-ab$ $(-a)(-b)=ab$   Proof 1:   $a0=a(0+0)=a0+a0$ hence $a0=0$   I don't really understand why $a0+a0$ proves that $a0=0$


I have a database server PostgreSQL and Postgis. I want to connect to database from ArcMap 10.2 , I tried Add Database Connection from arcmap menü.  I typed my connection informations and clicked database selection box, an error occured as following. My connection info is true. I can connect from pgAdmin to database.    I did not install ArcSDE to database server. I read before that I do not need SDE after 10.0 version.

I know this is a total noob question but then again, when it comes to PostgreSQL I am a total noob...    I have installed the OpenGeo suite on my computer, running Windows 7, 64-bit.  I have downloaded the tutorial data and have been working through it.  I would like to access the database that I have made with ArcGIS so I can start learning about how that works.  However, when I try to connect to the database using the "Add Database Connection..." I can't seem to figure out what to put in for 'Instance' - everything I've tried (localhost, localhost,54321, my IP address with and without the port, my computer name) doesn't seem to work.  I installed and created the nyc test database according to all the instructions in the OpenGeo tutorial pages but am at a total loss here.  I know this must be an easy thing to deal with, I just can't get my head around it.  Can someone with more experience throw me a bone on this one?    Frustratingly enough, QGIS connects to the database with almost no effort and everything works fine - but my organization is heavily ESRI focused and switching to QGIS is a long shot...  EDIT Thanks everyone for pitching in on this.  I really appreciate the advice, it's what makes this site great.  I have installed    OpenGeo Suite 3.0.1 with no extensions ArcGIS Desktop 10.1, no license for server   I just went to the Opengeo website and downloaded the Windows installer and installed the default configuration. I have tried every permutation for the instance name that I can think of - using colons and commas, my machine name, localhost, postgresql, server, my IP address, random curse words, anything I can think of.  I have been using port 54321 instead of 5432 because that is what the OpenGeo workshop told me to set up my 'nyc' practice database to use.    It seems that localhost should work, here is a shot of the server properties from pgAdmin:


Is it possible to assign a css stylesheet to specific pages only?  If so how?   Can I use something like this? Not sure how to specify the pages though?  add_action( 'wp_enqueue_scripts', 'enqueue_theme_css' );  function enqueue_theme_css() {     wp_enqueue_style(         'default',         get_template_directory_uri() . '/css/default.css'     ); }

Different pages often need different set of scripts and styles for them.  I use functions.php and construction like this to load scripts and styles:  function load_assets() {    wp_enqueue_style( 'styles', get_template_directory_uri() . '/css/styles.css');    wp_enqueue_script('main-js', get_template_directory_uri() . '/js/main.js'); } add_action( 'wp_enqueue_scripts', 'load_assets' );   I know I can put some condition here like this:  is_page()   but is there a better way?  Suggestion:  Can wp_register_script() be used to target specific pages?


Is  there any plugin that can update the wordpress database, specifically the wp_posts table or any other custom table in the database created by other plugins which has absolute url's of images and other assets?  So for example I have an image in a post:  <img src="http://old-domain.com/wp-content/uploads/images/img.png" />   How do I update it when moving to new-domain.com? And also I have created a plugin that does save absolute URL's on a custom table. Should I also provide the functionality to update those URL's? I'm currently using the content_url() method which returns an absolute URL for the assets that the plugin is saving. Is there any way of modifying this so it uses relative paths so there will be no need for a migrate functionality if ever? Thanks in advance!

I have a Wordpress database which was installed in a development environment... thus, all references to the site itself have a fixed IP address (say 192.168.16.2). Now, I have to migrate that database to a new Wordpress installation on a hosting. The problem is that the SQL dump contains a lot of references to the IP address, and I have to replace it with: my_domain.com.  I could use sed or some other command to change the that from the command line, the problem is that there are a lot of configuration data which uses JSON. So what? Well, as you know, JSON arrays uses things like: s:4: to know how many chars an element has, and thus, if I just replace the IP with the domain name, the configuration files will get corrupted.  I used an app for Windows some years ago that allows to change values in a database and takes care of the JSON arrays. Unfortunately, I forgot the name of the app... so the question is: do you know any app that allows me to do what I want?


Can LCM of n numbers be obtained by taking LCM of 2 numbers and then taking LCM of this resulting LCM and the next number in the queue until all the numbers are exhausted by repeating this process?  In other words, Is the following formula valid?  LCM of (a,b,c,d,....) = LCM of ((LCM of ((LCM of (a,b)),c)),d)...

Definition: The least common multiple of $a.b\in\Bbb{Z}$ is the smallest  $k\in\Bbb{N}$ that is divisible by both a and b.         Proposition: $\text{lcm}(\text{lcm}(a,b),c)=\text{lcm}(a,\text{lcm}(b,c))\tag{2}$    Proof: We want to show $\text{lcm}(\text{lcm}(a,b),c)\mid\text{lcm}(a,\text{lcm}(b,c))$ and $\text{lcm}(a,\text{lcm}(b,c))\mid \text{lcm}(\text{lcm}(a,b),c)$ such that $\text{lcm}(\text{lcm}(a,b),c)=\text{lcm}(a,\text{lcm}(b,c))$.  Let $k=\text{lcm}(\text{lcm}(a,b),c)$, then $c\mid k$ and $\text{lcm}(a,b)\mid k$, but if we let $l=\text{lcm}(a,b)$, then $a\mid l\,\,\text{and}\,\, b\mid l$. Therefore $c\mid k\,\,,a\mid k\,\,\text{and}\,\, b\mid k$, but then $\text{lcm}(b,c)\mid k$. Thus $\text{lcm}(a,\text{lcm}(b,c))\mid k$      Question: Does this makes sense, ifso can I do the same for $\text{lcm}(\text{lcm}(a,b),c)\mid \text{lcm}(a,\text{lcm}(b,c))$?


I have to show that $\sum_{i=1}^{\infty} \frac{A}{(1+r)^i} = \frac{A}{r}$. Where $ -1 < r < 1$. I tried putting it like: $$\sum_{i=1}^{\infty} \frac{A}{(1+r)^i} = \frac{A}{r+1} + \sum_{i=2}^{\infty} \frac{A}{(1+r)^i}$$ However I don't know how to continue from here on.  This is not a duplicate, most other questions require $|1+r|>1$ which is not necessarily the case here. I would be very grateful if you could help me out or give me pointers how to solve this!

Why does the following hold:  \begin{equation*} \displaystyle \sum\limits_{n=0}^{\infty} 0.7^n=\frac{1}{1-0.7} = 10/3\quad ? \end{equation*}  Can we generalize the above to      $\displaystyle \sum_{n=0}^{\infty} x^n = \frac{1}{1-x}$ ?   Are there some values of $x$ for which the above formula is invalid?  What about if we take only a finite number of terms? Is there a simpler formula?     $\displaystyle \sum_{n=0}^{N} x^n$   Is there a name for such a sequence?    This is being repurposed in an effort to cut down on duplicates, see here: Coping with  duplicate questions.  and here: .


Hello I am new to Latex and I was wondering how I can shade in the area that I have coloured in green? I would also like to make all the points surrounding it the same colour. I have attached my code that I have so far. Thanks \begin{document} \begin{tikzpicture}[>=latex]  \begin{axis} axis lines=middle, xlabel=\(x1\), ylabel=\(x2\), xmin= -1, xmax=5, ymin= -1, ymax=10, every axis plot/.style={very thick},             ] \addplot coordinates { (0,9) (3,0)}; \addplot coordinates { (0,5) (10/3,0)}; \addplot coordinates { (0,4) (4,0)}; \node[circle,fill,inner sep=2pt] at (axis cs:0,0) {}; \node[,circle,fill,inner sep=2pt] at (axis cs:2,2) {}; \node[,circle,fill,inner sep=2pt] at (axis cs:8/3,1) {}; \node[,circle,fill,inner sep=2pt] at (axis cs:3,0) {}; \end{axis} \end{tikzpicture} \end{document}`

iam trying to fill above the green and the red line, between the two brown lines. Ive tried it with soft clip and domain, but i cant get it working. Here is what iam trying to achieve (thick organe lines or just this space filled).  Code so far is: \documentclass{standalone}  \usepackage{tikz} \usepackage{pgfplots} \usepgfplotslibrary{fillbetween} \usetikzlibrary{patterns}  \begin{document} \begin{tikzpicture}     \begin{axis}[grid=both,ymin=-5,ymax=5,xmax=5,xmin=-5,xticklabel=\empty,yticklabel=\empty,       minor tick num=1,axis lines = middle,xlabel=$x_1$,ylabel=$x_2$,label style =       {at={(ticklabel cs:1.1)}}]       \addplot[draw=green, name path=A]{7/2 -2*x};        \addplot[draw=red, name path=B]{3/2 - x/2};       \addplot[draw=blue, name path=C]{1- x/3};        \addplot +[mark=none,draw=brown, name path=D] coordinates {(1,-6) (1,6)};       \addplot +[mark=none,draw=brown, name path=E] coordinates {(2,-6) (2,6)};      \end{axis}   \end{tikzpicture} \end{document}  Thanks in advance!


Im trying to get only the number after the dot in a number  float number; printf("Enter a real number:\n"); scanf("%f", &number); int integerPart = (int)number; int fractionalPart = (int)((number -(float)integerPart) *1000); printf("The fractional part: %d\n", fractionalPart);   when i put 256.589 i get output of 588 why?

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


I've just completed updating to High Sierra. I've also successfully installed GNS3 (Network Simulator for Cisco studies) on High Sierra. I get the following message in the console while trying to access the CLI for the network devices with iTerm.   sh-3.2$ exec telnet 192.168.56.101 5000 sh: exec: telnet: not found   The following message shows up when I try and use Terminal.  -bash: telnet: command not found logout Saving session... ...copying shared history... ...saving history...truncating history files... ...completed.  [Process completed]   Any help would be appreciated.

There are  with not having ftp and telnet present in 10.13 now as per Apple's dictate.  Has anyone found a solid way to bring BSD ftp and telnet back to macOS vs using inetutils?


I'm looking to be able to digest and comprehend some basic fundamental concepts, so that I may apply them in my hobby of electronics.   I got a copy of "Fundamentals Of Physics" by Halliday & Resnick. The teaching style is pretty bland,lacking very little detail, and most concerning is the fact that right out the gate your comprehension of concepts is tested by over the top questions, basically the level of complexity excels to quickly.  I have self-studied out of books that get real complicated, but its after proper instruction, and your not that worried about anything when you get there cause you know you have digested all the prerequisite subjects well.   Im looking for a high-school level physics book like that, it gets complicated, but it's very instructional and progressive. Does anyone know of any good physics books that fit the description?

Every once in a while, we get a question asking for a book or other educational reference on a particular topic at a particular level. This is a meta-question that collects all those links together. If you're looking for book recommendations, this is probably the place to start.  All the questions linked below, as well as others which deal with more specialized books, can be found under the tag  (formerly ).  If you have a question to add, please edit it in. However, make sure of a few things first:   The question should be tagged  It should be of the form "What are good books to learn/study [subject] at [level]?" It shouldn't duplicate a topic and level that's already on the list   Related Meta:


I'm trying to make a beamer presentation for a talk. The title of the talk is fairly long. I want to figure out how to make sure only the last part of the title is displayed footer of the slide. I attempted to use the \subtitle command, but it only forced the beginning of the title to shift down. Is there anyway to fix this?  \documentclass{beamer} \usetheme{Boadilla}  \AtBeginSection[] {     \begin{frame}<beamer>         \frametitle{Roadmap}         \tableofcontents[currentsection]     \end{frame} }     \subtitle{Some results on the notion of} \title{Independence on Simple Theories}  \begin{document}  \frame{\titlepage}  \end{document}   This produces "Independence on Simple Theories" in bigger letters followed by "Some results on the notion of" by smaller letters, but I want, "Some results on the notion of" by smaller letters followed by "Independence on Simple Theories". This is one fix for my problem, but any other solutions to make the footer always show "Independence on Simple Theories" in the footer will also work.

How can I show a shorter title so it doesn't get cut, this is an example of my problem.  In the bottom part the title is cut before finishing so i want to show something shorter just [Lorem Ipsum and other stuff] and not the full title. I am new to using beamer and i have been in latex just a couple months, any help would be appreciated, thanks.


The following code gives output as 1, 4, 4 in C whereas  1, 1, 4 in C++  #include<stdio.h>  int main()  {       char ch = 'A'; //initialise      //printing output     printf("%d, %d, %d", sizeof(ch), sizeof('A'), sizeof(3.14f));         return 0;  }

In C++, sizeof('a') == sizeof(char) == 1. This makes intuitive sense, since 'a' is a character literal, and sizeof(char) == 1 as defined by the standard.  In C however, sizeof('a') == sizeof(int). That is, it appears that C character literals are actually integers. Does anyone know why? I can find plenty of mentions of this C quirk but no explanation for why it exists.


In the , there is this phrase:     For many people the NIST and also the Brainpool curves have an doubtful origin   I've read elsewhere that people have doubts about the NIST curves, but I've never heard anything disparaging about the Brainpool curves. What could the release notes be referring to?

I would like to get a USB token to secure my keys. My use case is protection of 3 GnuPG keys that I will be using 10 times per day at least. I plan to create a new key ring from scratch. Because ECC seems more future-oriented than RSA, this is what I chose to use. I'm wondering which USB token to choose as well as which curve.  On  it is said that many people think curves recommended by the NIST or defined by Brainpool have a doubtful origin; therefore, they recommend the non-standardized Bernstein’s Curve 25519. On  one poster says that    He is not aware of any profound criticism of Brainpool curves, and Bernstein’s Curve 25519 is hard to protect against side-channel attacks when implemented in embedded devices.   As a result, I'm a bit lost as to which key/curve to choose.


What exactly happens when you format/wipe a hard drive ? Is it overwritten with random data or something else ? Is the format process the same for all types of hard drives and for all brands ? Also, will it be harder to recover data from my hard drive if I format is repetedly, like 15-20 times ?

How does formatting work in Windows?  Does it erase all the data on the drive to 0? What's the difference between fast format and normal format? If it doesn't set all the data in the drive to 0, how can I do that?


I am not able to regenerate my bombs and potion after meditating,though I have high level alcohols(like alcohest,dwarven spirit etc).

I'm sure I have the recipe for the Samum Bomb (to destroy monster nests). But after using two of my own crafted bombs, I see 0/2 in my inventory.  If I try to recreate such bombs with the matching ingredients, I get the hint: "You already have this item". That's not really true .-) Actually I have 0 of 2 of this bombs and can not destroy a third nest.  How can I replenish my stock of Samum Bombs?


I want to place a png file floating over my 3D model's face to create eyes. I've placed the image on a plane that I've UV unwrapped.  The problem I have is that when I render the image, you can see straight through his head.  How can I achieve the desired result?  I'm new to blender so go easy :)

I added two planes in Cycles with Image Texture in png with some transparency. I covered one by the other but transparency doesn't work, I mean it is impossible to see the one which is under despite transparency in the one which is above. What could be the problem?


Let $\{u_k\}$ be a sequence in $\mathbb{R}^n$. Prove that if $u_k$ converges, then $\{||u_n||\}$ converges.

If $\langle X_n \rangle$ is a sequence in $\mathbb R^n$ then $\lim\limits_{n\to \infty}X_n=A$. Show that $\lim\limits_{n\to \infty} \| X_n \| = \| A \|$ .   My thought process, $\| X_i \|= (\sum_{i=1}^n x_i^2)^{(1/2)}$ therefore be the multiplicative property of limits $x_i^2 = a_i^2$. Therefore the limit of norm of the components is equivalent to the limit of the corresponding limit of each component of the sequence.


I am new to c#.  I do have some experience testing javascript.  I was looking at assessing this test similar to checking for a method to be called in with a spy via sinon.  However,  I am not truely sure what to test.  As I noted I am pretty new to c# and am doing testing to get a feel for how the code works.  Here is the private method that I need to test for    private TicketResponse.PaymentType GetPaymentType(TicketResponse.FormOfPaymentCreditCard paymentType, VCR_DisplayRSTicketingInfosTicketingInfoTicketingTicketDataTourInfo tourInfo)     {   I read that I test the interfaces. So I am testing something along these lines?   public enum PaymentType {     CASH, CREDIT_CARD, NITP, TRAVEL_CREDIT, GIFT_CARD, JETBLUE_REWARDS, NONE, CHECK, EXCHANGE }   Any insight would be super helpful thanks.

I'm building a class library that will have some public & private methods. I want to be able to unit test the private methods (mostly while developing, but also it could be useful for future refactoring).  What is the correct way to do this?


I can separate single faces in the UV editing mode. I disabled sync selection and sticky vertex selection. But when I select two faces in a group of joined faces, I can't separate them by pressing Y. I have blender 2.74.  How can I split a group of joined faces in the UV mode?

How do I break the selected UV map from its surrounding vertices?


I recently purchased dell laptop with the graphic card specification as provided above but could not get the required driver ? Please help anyone from Ubuntu community and please leave link if any for the same...! I have downloaded from their official site but is yet after double clickin and all yet not able to figure my way out

I just ordered the Nvidia GTX card. I have a dilemma, though. Should I keep using the driver which is available in "additional drivers" in Ubuntu, or should I install the driver from the Nvidia site?  So which driver is the best for me?


If we say, Is this necklace yours?  Then would it be the same if a dog has a necklace and we refer it by saying, Is the necklace its?  It sounds so weird to me but is it grammatically correct?

Since its can be both determiner possessive pronoun and nominal possessive pronoun, an example of its as determiner possessive pronoun would be:     We saved this question for last because of its complexity.   Because complexity is a noun, so its must be a determiner possessive pronoun in this sentence. I'm looking for an example where its is used as nominal possessive pronoun in a sentence as above.


I'm trying some voronoi with Sverchok and I've see a videa that referes to 3D voronoi node but i found that to run it i need scipy installed. I've tryied to install it from sverchok from comand line and from anaconda but I cant made it work. I have blender 2.92 and I use Win 10

I'm currently developing a script for Blender to handle Mesh Frequency Decomposition.  The script is nearly complete, but i need one more thing: The SciPy library to compute eigenvalues and eigenvectors.  Following the installation instructions on , I'm able to install it as well as Numpy. Numpy works fine, but I can't even import SciPy:  Traceback (most recent call last): File "/CAF_FD.py", line 4, in <module> ImportError: No module named 'scipy' Error: Python script fail, look in the console for now...   By the way, I'm working on Linux 64 bit and I've installed SciPy and Numpy with my package manager.  Edit: When I try to use SciPy with a terminal prompt, it works.


I've checked reliable sources (i.e. man pages, --help, even apropos, which gives best command per the situation, but wound up eventually just confusing me further. So, I've tried other methods first, as suggested. So, when is it best to use 'apt-get', 'apt', or 'aptitude' and why/why not for this versus for that?  P.S.~ I listed no Distro because of the fact that this is, so far as I have seen, universal in *buntu, from 18.04 on, including 19.04 (disco) Kubuntu, Ubuntu, Ubuntu MATE, LXDE/LXQt&Lubuntu, and you get the point.

I read about the new fancy progress bar which was added to apt 1.0 in  and how to enable it . However on running sudo apt-get update, I did not see the fancy progress bars. On reading the second link again, the solution explicitly requires you to use sudo apt update.  Hence my question is the difference between apt and apt-get. I thought they were one and the same.


I am running these commands to reinstall php5.6 and I getting this error:  add-apt-repository ppa:ondrej/php     W: GPG error:  stable Release: The following   signatures couldn't be verified because the public key is not   available: NO_PUBKEY 6494C6D6997C215E W: There is no public key   available for the following key IDs: 1397BC53640DB551 W: Failed to   fetch      404  Not Found [IP: 172.217.8.142 80]      E: Some index files failed to download. They have been ignored, or old   ones used instead.   Please advise

I added some extra repositories with the Software Sources program. But when I reload the package database, I get an error like the following:     W: GPG error:  trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8BAF9A6F   I know I can fix it using apt-key in a terminal, according to the official Ubuntu documentation. But I would have liked to do it graphically. Is there a way to do this without using a terminal?


Players of a certain TRPG have characters with 6 ability scores, each ability score ranging from 3-18. One method of generating those is by rolling 4d6 drop lowest. That means four six-faced-dice are rolled, and the three highest results are added.   What's the probability that, given 5 players, one player will have a highest ability score equal or lower than the lowest ability score of another player?   The related question  shows how to get the distribution of 4d3 drop lowest, but how do I get from there to an answer of my question above?   A good answer would explain the result in a way that a statistics novice can follow.

Repeatedly rolling a six sided die four times and summing the highest three results gives you a distribution with what mean and standard deviation?  I've only taken AP statistics, but I would like to learn how to do this.


Let $\sum_i a_i$ be a convergent sum, with all $a_i$ positive.  Let $s_n=\sum_{i=n}^{\infty}a_i$.      Does $\sum_i  \frac{a_i}{s_i}$ always diverge?   I've tried a few examples such as $a_i= r^i$ (geometric series) and $a_i=1/i^2$ and it seems to always diverge.

Let $\displaystyle \sum a_n$ be  convergent series of positive terms and set  $\displaystyle b_n=\sum_{k=n}^{\infty}a_k$ , then prove that $\displaystyle\sum \frac{a_n}{b_n}$ diverges.   I could see that $\{b_n\}$ is monotonically decreasing sequence converging to $0$ and I can write $\displaystyle\sum \frac{a_n}{b_n}=\sum\frac{b_n-b_{n+1}}{b_n}$, how shall I proceed further?


I would like to abbreviate \begin{frame} \end{frame} environment of Beamer. For most Latex environments, I could do this using a basic \def command: \documentclass{article}  \def\be{\begin{enumerate}\item} \def\ne{\item} \def\ee{\end{enumerate}}  \begin{document}  \be One \ne Two \ne Three \ee  \end{document}  This works and is much more compact than the full syntax. But if I try to do something similar for Beamer it doesn't work: \documentclass{beamer}  \def\be{\begin{frame}} \def\ee{\end{frame}}  \begin{document}  \be A frame \ee \be Another frame \ee  \end{document}  Runaway argument? \let \AtEndDocument \@firstofone \@enddocumenthook \@checkend {docume\ETC. ! File ended while scanning use of \beamer@collect@@body. <inserted text>                 \par  Why wouldn't this work for the frame environment in particular?

Aware abbreviating those commands need not always be helpful, I would like to know how to abbreviate them? The following is what I tried, which does not work:  \documentclass[11pt,handout]{beamer} \newcommand{\bframe}{\begin{frame}} \newcommand{\eframe}{\end{frame}} \newcommand{\ftitle}{\frametitle}   \author{Author} \title{Title}   \begin{document} \maketitle  \begin{frame} \frametitle{Outline}  \end{frame}   \bframe \ftitle{Introduction}  \eframe    \end{document}   At first I thought it might be the case that commands such as \bframe was already defined. But using \def instead still gives no desired result.


As it stands, the "First Posts" review queue is empty on Stack Overflow. As I seldom review that queue, it isn't empty because I have no posts to review; it's empty because, well it's empty.  However, in reviewing some of the 800 flags in the 10k Flag Queue, I came across so, so many posts by first users, which are blatantly low quality/ NAA, most of which had no comments at all, and those that did, I'm doubtful whether they were added during the review of the post in the "First Posts" queue (if it ever reached there).  Note that the guidance for the FP queue reads (emphasis mine):     Be sure to leave a comment if you can help the user out, upvote the question if you can't find any problems with it, or click Skip if you are not sure and want to go to the next item.   It seems a waste of everyone's time if all of the following posts had to cycle multiple reviews, be seen by 10k'ers in the 10k  queue, before been seen and finally handled by diamonds (and the whole while, the OP has no idea they've done anything wrong, due to the lack of feedback):                 ... and there's more, many more, but you get the gist.  How can the "First Post" queue be changed to better address this?   Should the addition of a comment be enforced if a "flag" was made? An extension of the above; a comment for anything other-than an up vote (yes, even a downvote)? Should the ability to "Delete" / "Recommend Deletion" exist like the LP queue Do we need more pairs of eyes per-post to ensure the correct action is (eventually?) taken? Would the current system work, except the robo-reviewers are making this queue so ineffective? ...?

There's now a feature-request based on this discussion; see:   I'm about fed up with the First Posts review queue. Oh, it was : give folks a chance to welcome new users to the site, without  with Low Quality review. The problem is, the review system was designed around the idea of guiding folks to accomplish specific goals. And there's no clear goal for First Posts. Without a goal, folks tended to just , until we "fixed" that by adding a "do nothing" button and strict audits. Great fix! , and those that do find that trying to automatically audit an open-ended system is . It's the same problem we had with , with the addition of . So yeah, this review queue is terrible and useless But before throwing the baby out with the bathwater, I figured I'd best check with y'all to see if any baby even lurks in these murky depths.  What value do you see in having a First Posts review? What outputs do you see as valuable from such a queue?  I'm thinking we could probably make this work if we narrowed the focus considerably; less "help new users in some mostly-unspecified way" more "help filter the wheat from the chaff":  Separate queues for questions and answers, with answers being sanity-checked for spam and questions requiring one vote - up or down. Essentially answer voting would be left to those with a specific interest in a given question (as it should be) while question voting would be used as .  Allow flagging, commenting, comment voting, etc... But don't count those as a review action (unless we decide that the goal of reviewing these is to dramatically increase the number of comments or something, in which case we should probably drop that & try jSobriety).  Send more things into the queue faster, remove them more quickly if they're "reviewed" organically. Less waiting for a new post to get attention, but less duplicate reviewing when something is getting attention without the need for review.   ...Thoughts?


I’m super new to DnD and I was hoping to get some clarification on a few things.  My character has a long bow and a short sword. For the longbow it has an ATK bonus of +5 and damage/type of 1d8 +3 piercing... my question is how do I calculate that? Do I role the d8 then add +5 and +3? Or what do?

I'm building my character, a Half-Elf Ranger, and I'm a little confused about how to work out the attack bonus and the damage bonus.  So, please tell me if I've got this right:   I'm proficient with a longbow. That means my attack roll is 1d20 + prof bonus + Dex modifier. The damage roll however is 1d8 + Dex modifier.   I'm just a little confused about working out the numbers (without even going into spells and when to roll for attack, etc.)


I have two components, one component is a child of another component. I want to access value present in controller of child vf component in controller of parent vf component. Can anyone suggest how to do this? Thanks.

I have a VisualForce page that is made up of different components. One of my components is passed in a Case and displays the case fields.   If there is an edit to the case I would like to save it with associated controller to that component. If saving produces an error I would like to pass that error to the parent VisualForce page/controller and display the error message there.   Is it possible to communicate with other components/VisualForce pages? I am looking for something similar to an event in lightning components.


To see my /etc folder I've tried this command in Terminal:  sudo chflags nohidden /etc   followed by:  sudo defaults write com.apple.Finder AppleShowAllFiles true; killall Finder   also tried:  sudo defaults write com.apple.Finder AppleShowAllFiles YES; killall Finder   Neither of them seemed to work.

I need an easy way to switch files visibility on Mac. I know about Terminal commands how to show hidden files and hide files. However, I need a tool to make this task faster and easier.  I was trying to find a special app in the App Store, but found nothing. Is there any way to show/hide hidden files without launching Terminal? Any tips or apps?


Is there a way (except click-right → Open Link in Incognito Window) to make Google Chrome open all links in an incognito window from normal browsing mode?

When launching Chrome from the Windows command line I can pass arguments like so:  ...>chrome.exe -incognito   I can also pass a URL to open:  ...>chrome.exe google.com   Each work fine on their own, but I can't get them to work together.  What I want is to launch it with a URL, and open in its own tab, and hide the URL, buttons, etc., like a utility window, but I do want it resizable.


I would like to evaluate this limit without using Taylor expansion:  $$\lim_{x \to 0} \frac{e^x-x-1}{x^2}$$ .  Note: by Taylor Expansion i have got  :$\frac{1}{2}$ .  Thank u for any help .!!!!

Is it possible to determine the limit  $$\lim_{x\to0}\frac{e^x-1-x}{x^2}$$  without using l'Hopital's rule nor any series expansion?  For example, suppose you are a student that has not studied derivative yet (and so not even Taylor formula and Taylor series).


I'm building a whip character, and one of the class features I get allows me to pick one exotic light or one-handed melee weapon that has the disarm or trip special feature and become proficient with it. I get this from the Magus archetype . I like the fact that the scorpion whip allows me to deal lethal damage, regardless of natural armor and armor, but its description confuses me. A  is a exotic light weapon, and a  is a exotic one-handed . Whip  A whip deals no damage to any creature with an armor bonus of +1 or higher or a natural armor bonus of +3 or higher. The whip is treated as a melee weapon with 15-foot reach, though you don't threaten the area into which you can make an attack. In addition, unlike most other weapons with reach, you can use it against foes anywhere within your reach (including adjacent foes). Using a whip provokes an attack of opportunity, just as if you had used a ranged weapon. You can use the Weapon Finesse feat to apply your Dexterity modifier instead of your Strength modifier to attack rolls with a whip sized for you, even though it isn't a light weapon. Weapon Feature(s): finesse, reach.  Scorpion Whip  Benefit: It deals lethal damage, even to creatures with armor bonuses. If you are proficient with both scorpion whips and whips, you can use a scorpion whip in either the normal way, as a typical light performance weapon, or as a whip. If you are proficient with both the scorpion whip and whip, you can use a scorpion whip in either the normal way (as a light performance weapon) or as a whip. When you use a scorpion whip as a whip, it is equivalent to a whip, but deals lethal damage and can harm creatures regardless of their armor bonus. Weapon Feature(s): performance (plus disarm, reach, and trip if you are proficient with whip.)    When wielding this weapon, if an attack or combat maneuver made with this weapon prompts a combat performance check, you gain a +2 bonus on that check. See Gladiator Weapons below for more information.  So what is the normal way of a light performance weapon, and how exactly does that differ from a whip?

The Scorpion whip says:   This whip has a series of razorsharp blades and fangs inset along its tip. Benefit: It deals lethal damage, even to creatures with armor bonuses. If you are proficient with whips, you can use a scorpion whip as a whip. Weapon Feature(s): performance (plus disarm, reach, and trip if you are proficient with whip.)  This seems very unclear though. Does it have 15' reach? Does it threaten? (At 5'? At 10'? At 15'?) Does it do nonlethal damage if used at 15'? I've found quite a bit of discussion online but mostly people arguing, nothing definitive.


I'm having trouble solving the differential equation $y''y^3=1$.  Usual method is, since there is no $x$ in the equation to use the substitution $y'=p$. We can write $$y'' = \frac{dp}{dx} = \frac{dp}{dy} \frac{dy}{dx} = \frac {dp}{dy} p$$  The equation becomes:  $$py^3 \frac{dp}{dy}=1 \iff \int{p dp} = \int{\frac{dy}{y^3}}$$  $$p^2 = -\frac{1}{y^2}$$  Now if we could just take square root, the equation would be separable and we are done, but the solution that is given: $A y^2 = 1 + (Ax+B)^2$ is not of complex form. Perhaps the given solution is wrong or I have made a mistake somewhere.

I'm having this question in my homework assignment in Linear Algebra and diffrential equation class, and trying to find the general solution for this second ODE.  $$y''y^3 = 1$$  Using substitution I said $p = y'$ and $p' = y''  \rightarrow  \frac{dp}{dx}= \frac{dp}{dy} \times \frac{dy}{dx}$  Then we get $y^3 \frac{dp}{dx}$ now what's the next step should I integrate or differentiate the equation? What's the trick on these type of ODEs?  Thanks in advance!


I have the following formula:    Is there an elegant way to make the matching brackets of one level a little bigger than the matching brackets of the previous one?  Normal -> () -> Bigger -> [] Bigger -> {}  \documentclass{article} \usepackage{parskip} \setlength{\parindent}{0cm} \usepackage{amsmath} \usepackage{unicode-math} \usepackage{fontspec} \usepackage[greek,english]{babel} \setmainfont [     Ligatures=TeX,     Extension=.otf,     UprightFont=*,     BoldFont=*Bold,     ItalicFont=*It,     BoldItalicFont=*BoldIt,     Mapping=tex-text ]{GFSArtemisia} \setsansfont[Mapping=tex-text]{GFSArtemisia.otf} \setmathfont{latinmodern-math.otf} \setmathfont[range=\varnothing]{Asana-Math.otf} \setmathfont[range=\int]{latinmodern-math.otf} \usepackage{lipsum}  \begin{document}  Formula: % \Eqs {   y_{n+1}=y_{n}+\frac{h}{2}\{f(x_{n},y_{n})+f[x_{n}+h,y_{n}+hf(x_{n},y_{n})]\} }  \end{document}

I have this expression: |x-|x-|x-4||| Now, every | sign has the same size, but I'd like to make the outward pairs bigger.   Is it possible to do it automatically, or do I have to define the size of each | sign manually? It doesn't work with $\left| \right|$. In this case I have 3 abs signs. But what if there would be for example 12? Is it possible to do it automatically?  This works fine:   \[ \abs*{\VPhantomL x-\abs*{\VPhantomM x-\abs{x-4}}} \]     But the inline version doesn't:  $\abs*{\VPhantomL x-\abs*{\VPhantomM x-\abs{x-4}}}$


How can I print the coordinates of resolution points of a Bezier Curve?

I've used mathutils.geometry.interpolate_bezier() in the past to create points for a curve using the bezier handle and knot coordinates.  from the docs:     interpolate_bezier(knot1, handle1, handle2, knot2, resolution)   My question is; given an existing curve in the scene, is there a neat way to get at the points that describe the curve without converting it to a mesh, or figuring out which handle (left or right) to use for each spline point.  curve = bpy.data.curves[0].splines[0] curve.bezier_points[0].co curve.bezier_points[0].handle_left curve.bezier_points[0].handle_right


Table:   UserId, Value, Date.   I want to get the UserId, Value for the max(Date) for each UserId. That is, the Value for each UserId that has the latest date. Is there a way to do this simply in SQL? (Preferably Oracle)  Update: Apologies for any ambiguity: I need to get ALL the UserIds. But for each UserId, only that row where that user has the latest date.


In the excellent  to the question  he said that     [t]his is not completely foolproof and there are examples around of cleverly written documents that never stabilize: each new run of LaTeX will change the page number associated to a label so it never remains the same. However, the chances that this happens in a real document are pretty small.   Does anyone happen to have such an example of source code?  I see how this works and I thought about this several times, but I was not able to simply create a document where this happens.

It is an unfortunate reality that one must compile a LaTeX file several times in order to get all labels and citations correct. As far as I know, one should go on compiling as long as TeX warns that that "labels may have changed", and two or three passes may not be enough.  Is it possible to write a LaTeX document that never stabilizes, i.e., no matter how many times I compile it, it will go on complaining that labels have changed?  I am thinking about something like a \pageref{something} written in a large font that moves from page 9 to page 10, which requires longer to typeset and thus makes the corresponding label change page and so on ad infinitum.


What I mean by one way relay is manually reset it to run again. What I need it for: I want a pump to run when a relay is on(manually turned on), when there is no power the relay trips and stays like that in off position. Because even if the power comes back on I don't want the pump on. Until I reset the relay. I keep saying a relay, but it doesn't have to be. Anything that could handle 240V. Is there anything I could use for this?

I am trying to set up a circuit where a "switch" is locked into closed from "NO" using 12 vdc trigger.   Once the "switch" is closed, it would take another 12 vdc to return to the "NO" position.   The return could also be accomplished with a manual button.  I have been searching and found self latching relays and that looks like what I want, but they seem to either have wireless or buttons for activation.   There are also "bistable" and others that do not list as "bistable".  I have no idea what that means.   I am trying to latch a small circuit (5 vdc 200ma) closed and then later reset to the normally open when I am done with my process.   I want to trigger the relay with 12 vdc.  It stays in the latched position (closed) without power applied.  Power interruptions would have no effect on the circuit.    The small circuit (5 vdc 200ma) is part of a logic control in a PLC where it is an Exit Condition if "On".   Basically, I have several Steps in a Process and have been manually turning a Toggle Switch "On"  and close the circuit when part of the Process is complete.   If that part of the Process is complete, a Power interruption would cause the Process to re start automatically at Step 1.  If step 1 is complete and the logic Toggle is closed, the Process Jumps to State 2.   I have several steps and need a board that has at least  6 latching relays. My quandary is that I cannot find instructions on how these boards work.  It seems that many have buttons for activation, but that would do me no good as I already can manually turn on the Toggle.  Some talk about adding a trigger switch but give no additional information.   I want it automated and can logically apply a 12 vdc trigger when the Step is complete. Can someone point me to a relay board that would do what I want?


I switched over to xubuntu, but one of the most important things that I really need/use seems to not be available for Linux. It's Google Drive, and the ones that I've tried such as Grive, just don't work properly (it syncs the first time you install it, but it doesn't sync again, not even if I do it manually).  So I wanted to ask if there's any good software out there for Ubuntu, that does work properly, that is a cloud based storage system with decent quota's, like 10 GB if possible.

I'd like to install a  client for Xubuntu (12.04).  I'm getting non-English Google results, and I didn't find  in the Xubuntu repositories.   Does anyone know of a client that works well for Ubuntu or it's supported derivates (or installation instructions for grive?)


Salesforce is going to disable SSL 3.0 encryption on 7th November for all the sandbox instances and later for production instances. In sandbox environment, my .Net client application using OAuth 2.0 Web Server flow and salesforce APIs to communicate with salesforce.  How could I verify that my API integration is using SSL 3.0 encryption and how could I change it to TLS 1.0?

I have developed an application in C# that makes use of the Salesforce API via a WSDL and need to ensure that the upcoming disabling of SSL3.0 will not affect functionality. I have never had to do any specification of the security protocol when using the webservice, so I am not sure what to do.  How do I:   Determine what protocol is currently being used in my implementation. Set it to use TLS (if necessary)


To see my /etc folder I've tried this command in Terminal:  sudo chflags nohidden /etc   followed by:  sudo defaults write com.apple.Finder AppleShowAllFiles true; killall Finder   also tried:  sudo defaults write com.apple.Finder AppleShowAllFiles YES; killall Finder   Neither of them seemed to work.

In macOS Sierra, it used to be Command + Shift + .. But that does not appear to work in macOS Mojave. Has something changed?  What is the keyboard shortcut to show/hide hidden files in Finder without restarting in macOS Mojave?


Note that by "generate the same topology" we mean that any set that is open with respect to $\lVert\cdot\rVert_1$ is also open with respect to $\lVert\cdot\rVert_2$ and vice versa. By "equivalent" we mean that $\exists m,M>0$ such that $m\lVert x \rVert_2\leq \lVert x \rVert_1 \leq M\lVert x \rVert_2$.  This is part of an old preliminary exam in Analysis I'm using to prep for my own prelim. I have already proven that equivalent $\implies$ same topology, but the other direction is causing me trouble. I've been attempting a reductio, supposing that for some open $A$ we have $\inf_{x\in A} \{m>0: m\lVert x \rVert_2 \leq \lVert x \rVert_1\}=0$. I don't see any contradiction here, though.

Whenever two norms are equivalent in the sense that $\|x\|_1\le c_1\cdot \|x\|_2$ and $\|x\|_2\le c_2\cdot \|x\|_1$, they generate the same topology. Is the reverse also true, i.e. if a topology is generated by two different norms, are the norms equivalent in the above sense? We know this to be true for $\mathbb{R}^n$, but is it generally true, and if not, what are some counterexamples?  What about a Hausdorff, translationally invariant vector space topology generated by two different metrics, are the metrics equivalent in the sense $d_1(x,y)\le c_1\cdot d_2(x,y)$ and vice versa?


If you have taken the time to merge your MyOpenID StackOverflow (and StackExchange) account into a social network account such as Google or Facebook, can you describe the workflow (maybe with screen shots)?  Many will be confused on February 1, 2014, so I thought having a question and some answers with a solution will be nice to have.  I will take the time soon and do it myself.  I'm sure there will be answers for the following account types, unless someone takes the time to answer for all of them.  Facebook, Google, Twitter, LinkedIn, Yahoo  Note, this question doesn't show you the steps to merge, so it's not entirely helpful to save hundreds of millions of users time.    See this for reference:    Quote from site above:  We have made the decision to end of life myOpenID, and the service will be turned off on February 1, 2014.  In 2006 Janrain created myOpenID to fulfill our vision to make registration and login easier on the web for people. Since that time, social networks and email providers such as Facebook, Google, Twitter, LinkedIn and Yahoo! have embraced open identity standards. And now, billions of people who have created accounts with these services can use their identities to easily register and login to sites across the web in the way myOpenID was intended.  By 2009 it had become obvious that the vast majority of consumers would prefer to utilize an existing identity from a recognized provider rather than create their own myOpenID account. As a result, our business focus changed to address this desire, and we introduced social login technology. While the technology is slightly different from where we were in 2006, we are confident that we are still delivering on our initial promise - that people should take control of their online identity and are empowered to carry those identities with them as they navigate the web.  For those of you who still actively use myOpenID, we can understand your disappointment to hear this news and apologize if this causes you any inconvenience. To reduce this inconvenience, we are delaying the end of life of the service until February 1, 2014 to give you time to begin using other identities on those sites where you use myOpenID today.

Janrain has , one of the many OpenID providers. MyOpenID will not be available starting February 1, 2014. (An   hinted at the same but did not set a date for end of service.)   This decision was made by Janrain, and Stack Exchange did not have any part in it. You can still use myOpenID to log in to Stack Exchange, but be aware that any outages in the myOpenID service will mean that you are unable to log in to Stack Exchange until Janrain fixes it – which may take several days, or weeks, or never. After February 1, you will no longer be able to use myOpenID to log in to Stack Exchange. Stack Exchange will not be able to answer any questions about why myOpenID is down or when it will be working again. If you do not have any other login credentials on your account by February 1, you will be locked out, and Stack Exchange will be unlikely to help you recover your account.  To avoid getting locked out of your Stack Exchange account, we strongly suggest that anyone using myOpenID as their primary (or even backup) login add a new login method to their Stack Exchange account.  We're also going to remove the "myOpenID" button from the sign-up/login page soon, in order to discourage new users from signing up using myOpenID.  Here's how to add a new login to your account. You must be logged into your account when you begin. (This information is also available .)  Open up your user profile page (by clicking on your login name at the top of the screen) and click the "my logins" link above the bio box on the right hand side.   You should see a list of all of your logins.  To add a new login, click "add more logins..." at the bottom of the box. Choose the new login from the list and follow the steps to confirm.    If you choose, you can remove your myOpenID login by clicking the same "my logins" link, then clicking "remove" next to myOpenID.  If you are adding a Stack Exchange OpenID, you will receive a confirmation email. You must click the link in the email to confirm your email address before the Stack Exchange OpenID will show up under "my logins". Please make sure that you are already logged into your account when you click the confirmation link; otherwise, you will create a new account that needs to be merged with your old one.    If you encounter any trouble adding logins, or accidentally create a separate account that you would like merged, please fill out our .


i recently started to do some encryption with Apache DigestUtils. I simply want to use md5 hashes for authorization, but i'm an absolute beginner in this topic and in general not really experienced in Java. The API of this library provided me the methods md5, md5hex. If i'm not mistaken the result of these just differs in the output as a hexString (i'm not even sure whats this means) and regular bytes.  String b1 = DigestUtils.md5hex("Some String"); String b2 = DigestUtils.md5hex("Some String");   The result is 83beb8c4fa4596c8f7b565d390f494e2 & 83beb8c4fa4596c8f7b565d390f494e2 But a comparison with == results in false      if (b1 == b2){       System.out.println("Matching")   }  I'm pretty confused and i can't find a source for an introduction around this topic(for java!)

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 Recently made an intro. I separated the text letters and converted to mesh so that I could do . Now everyone says I'm unable to go back to editable text mode. Is there an add-on to get back from mesh to text? Or any other way to transfer all key frames to a text object so I could get it back somehow?

I converted text to mesh now i want to convert mesh to text, how  i can do it?


I installed Ubuntu 20.04 LTS and when I open Ubuntu Software and click to install a program, it gives me this error:  (Visual Studio Code is an example.) this happens to the programs like mc-installer (minecraft installer) too. but always this command will install the program: sudo snap install program-name But sometimes I don't know the name of a program in command line. Something like Visual Studio Code. The next problem is: Ubuntu Software doesn't tell me the error! After the "cannot perform the following tasks:: is the end of the alert! But sometimes graphical way can install some programs, such as VLC Media Player. How can I do to fix the error of ubuntu software?

Completely confused with this new feature snap. I know this might be detailed question-answer but I need to know some info regarding it.   I have read that new application format, snap which can be installed by default in the latest long-term support release alongside traditional deb packages. So, Does it mean are there packages with .snap extension like .deb? Then, How to install?   The user can use newer versions of apps on older versions of Ubuntu without forsaking the stability of your entire system.  Is this the only difference between deb and snap? Does it only exist to LTS version or for non-LTS too?   With this, it is also said that Creating snaps is simplified for developers with the introduction of a new tool called “snapcraft” to easily build and package applications from source and existing deb packages. Is it useful to desktop user or only for developers ?


Is there a word for parents who have lost their children?  Obviously a child who has lost both parents is an orphan and has been orphaned.  I am struggling to find a word for parents who have lost their children, though.

To my knowledge,There is no single word that describes a "person who has lost a child."      We have "widow" and "widower" for a person whose spouse had died. We have "orphan" for a child whose parent or parents have died.    According to the quora question, the closest word is in Arabic: ثَكْلَى (thakla) which translates as "bereaved mother."  Though bereaved does not adequately describe 'loss of child' as it's definition is:      [to] be deprived of a loved one through a profound absence, especially due to the loved one's death.    My questions are:   If there is a word, what is it? If there is not a word, what word would Shakespeare have made up to convey the idea?


As shown in the figure, what the difference between :=, ?= and = I did a quick search without find out a good answer. Appreciate it.

Can anybody give a clear explanation of how variable assignment really works in Makefiles.   What is the difference between :   VARIABLE = value  VARIABLE ?= value  VARIABLE := value  VARIABLE += value   I have read the  in GNU Make's manual, but it still doesn't make sense to me.


I am trying to integrate the following integral:  $$\int_{0}^{1} \frac{dx}{(x^2+1)^2}$$  However, I am always getting the wrong answer in the end. What I have tried doing is the following: $$\int \frac{dx}{(x^2+1)^2} = \int \frac{1}{(\tan^2\alpha + 1)}\times \sec^2\alpha \text{ }d\alpha = \int \frac{1}{\sec^2\alpha}d\alpha =\int \cos^2\alpha \text{ }d\alpha$$ $$= \frac{1}{2} \int1+\cos(2\alpha) \text{ }d\alpha$$ Now, at this step I was trying to get $\alpha$ in terms of $x$ using the triangle. So I know that $\alpha = \arctan(x)$ and $\sin(2\alpha)=2\sin \alpha \cos\alpha = 2(\frac{x}{x^2+1})(\frac{1}{x^2+1})$. Upon substituting it back, I get that $$\int \frac{dx}{(x^2+1)^2} =\frac{1}{2}(\arctan(x)+\frac{x}{2(x^2+1)^2})$$ And when I try to find $\int_{0}^{1} \frac{dx}{(x^2+1)^2}$, I get: $$\int_{0}^{1} \frac{dx}{(x^2+1)^2} = \frac{1}{2}(\arctan(1)+\frac{1}{2(1^2+1)^2}) - \frac{1}{2}(\arctan(0)+\frac{0}{2(0^2+1)^2}) = 0.5177$$ However, the answer in the textbook is said to be $0.6427$ and interestingly enough, when I add a $2$ like so $$\int \frac{dx}{(x^2+1)^2} =\frac{1}{2}(\arctan(x)+\mathbf{2}\frac{x}{(x^2+1)^2})$$ I get the correct solution, which is quite odd since I based my solution on the fact that $$\frac{1}{2}\sin(2\alpha) = \cos(\alpha)\sin(\alpha)$$ So there should not be a $2$ there. I am probably missing something, which sadly I can't find...

$$\int \frac{1}{(x^2+1)^2}\mathrm dx$$ Look simple, but I stuck a little bit. What method is better in this situation? Please, help.


What's the difference in meanings between tactical and strategic?  My teacher told me tactical is short term whereas strategy is related with long time ambitions. But I think otherwise that both are synonyms. Please help me out in context of geopolitics.

I recently read this sentence:     It was a strategic move rather than a tactical one.   I have trouble interpreting it. Can someone help?


foo = 'eggs'  foo[:1] # the same is foo[0] foo[-1:] # the same is foo[-1]   Is there any advantage of one of these ways?  I ran into this over here   UPD. Can you go to the link? The variable path is a string there. And I was confused, why they were using a slice instead of a concreate index.  if path[-1:] == "/":

I need a good explanation (references are a plus) on Python's slice notation.   To me, this notation needs a bit of picking up.   It looks extremely powerful, but I haven't quite got my head around it.


I have two laptops on which firefox is installed. I want to merge the bookmarks. How can I achieve this ? Thanks in advance.

I am looking for a way to merge a bunch of different bookmark files without importing duplicates (or creating empty folders ... im looking at you firefox+bookmarkdd!).  I'm not looking to sync amongst browsers or computers, this is a one time merge of a bunch of different files.  Ideally I wouldn't have to install anything, as such I'd also be open to scripted solutions.