Summary of Study  Participants worked in pairs to complete three tasks. Periodically throughout the interaction, they evaluated one another across a variety of categories. The primary category of interest for this analysis is comprehensibility, which participants rated using a 100-point scale. We are interested in examining how comprehensibility ratings fluctuate over time.  Variables   Comprehensibility: Continuous, 0-100 Time: Continuous, 0-6 (represents the time at which the ratings occurred; ratings occurred at equally spaced intervals) Speaker: Categorical/grouping variable, 1-40 Pair: Categorical/grouping variable, 1-20   Summary of the Problem  I have fit and evaluated a number of polynomial mixed-effects models using the poly function to estimate orthogonal time terms to avoid autocorrelation. I fit the following polynomial models: null/intercept, linear, quadratic, and cubic growth. I also fit a piecewise model in which I recoded time into separate variables representing the first four data points (time 0, 1, 2, and 3) and the second three data points (time 4, 5, and 6), labelled time03 and time46. I then constrained the quadratic slope to occur only during time03. These models were informed by plots of the data (individual and group trajectories) showing a U-shaped trajectory over the first few data points and a linear trajectory over the last few data points.   I used likelihood ratio tests to compare models. With the addition of each polynomial term, model fit improved: null < linear < quadratic < cubic. When I compared the piecewise and the cubic models, both containing the same number of parameters, the piecewise model proved to be a slightly better fit. I'm including a plot of the group-level trend for reference at the end of this post.  When I call the summary of the model, the linear predictor over time 0-3 is not significant, poly(time03, 2)1, but the quadratic predictor is, poly(time03, 2)2. What is the interpretation of the significant quadratic trend when the linear trend is not significant?   Model Summary    Plot  Note that in the plot, time has been relabeled 1-7, but models were fit to data labeled 0-6.    Update  I realized I should have included orthogonal polynomials as one of the tags. I found the following posts related to that topic helpful: , , and .   I understand that the significant quadratic slope essentially represents the U-shaped curve over the first few data points, but I'm still confused about the non-significance of the linear term. I had assumed that if a higher-order polynomial is significant, then the lower-order terms would be as well, since I thought the higher-order term(s) represent curvature or deviation from the lower-order terms. Incidentally, in the cubic model fit to the entire data set consisting of all 7 points in time, poly(time, 3), all three predictors were significant.

I have a (mixed) model in which one of my predictors should a priori only be quadratically related to the predictor (due to the experimental manipulation). Hence, I would like to add only the quadratic term to the model. Two things keep me from doing so:   I think I read somehwere that you should always include the lower order polynomial when fitting higher order polynomials. I forgot where I found it and in the literature I looked at (e.g., Faraway, 2002; Fox, 2002) I cannot find a good explanation. When I add both, the linear and quadratic term, both are significant. When I add only one of them, they are not significant. However, a linear relation of predictor and data is not interpretable.   The context of my question is specifically a mixed-model using lme4, but I would like to get answers that could explain why it is or why it is not okay to inlcude a higher order polynomial and not the lower order polynomial.  If necessary I can provide the data.


Consider a metal rod between two bodies of different temperature.How do you explain the occurrence of steady-state when heat Is transferring by conduction through the rod. I mean why should there exist a point called steady-state in the first place, meaning why the temperature of the rod at a point become static in steady state?

Suppose a cylindrical rod is maintained at 100 degree Celsius and the other at 0 degree Celsius. My book says that after reaching "Steady State" the rod will have developed a constant temperature gradient all throughout the rod.  Why does the rod reach a steady state shouldn't the rod keep absorbing heat until it reaches 100 degrees.  Assume the curved portion of the rod is perfectly insulated.


Once I establish a ground plane in Eagle PC, how can I relieve it(remove spots locally)  such as under smd caps in a filter circuit to avoid impedance change. Andy-KM4TRT

As title EAGLE don't allow me to draw a clear space inside a polygon. I've a GND polygon plane and I don't want that a zone inside it is filled with this plane.  How I can do that?


Anyone remember the method for this? I think this should been done on the site $$\int_0^{\infty}\frac{\ln x}{x^2+a^2}\mathrm{d}x$$

How do I integrate the following function: $$\int_{0}^{\infty} \frac{\log{x}}{x^{2}+a^{2}} \ dx $$ Integrating by parts looks very difficult.


Why am I unable to review First Posts and Late Answers? Am I now prohibited from reviewing posts? Or is it some technical error?

Is it just for me, or has the privilege to review new posts and late answers changed for everyone?  I recently started being more active in reviewing, but the rep requirement just shot up and I can not review anymore? The rep requirement has shot up to 500. Is this just for me, as a 'process", or has it been changed site wide?


If $a$, $b$, $c$ are positive real number and abc=1. Then prove that $$\frac ab+\frac bc+\frac ca\geqslant a+b+c$$ Using AM-GM both sides will be greater than $3$, But I don't know how to proceed further. Which inequality should I use?

If $a,b,c > 0$ are such that $abc=1$, then   $$ \frac{a}{b} + \frac{b}{c} + \frac{c}{a} \geq a + b+ c. $$   I would be pleased if you give me a hint. Thanks in advance.


Is there any tool in Ubuntu to create a bootable USB stick of an OS other than Ubuntu? Like Universal USB Installer in Windows.

I need a reliable application which will make usb pen drives bootable. Recently, I tried creating a bootable lubuntu-13-04-alternate usb on a ubuntu 12.10 system but ended up with 'boot error' when trying to boot. I tried startup disk creator as well as unetbootin. This is not the first time I am experiencing this, rather the above two utilities have always had high failure rates in my experience. Universal-usb-installer, YUMI, LiLi have worked great whenever I tried them, but all of them are windows only! So I have two questions:   What is the method to reliably create a bootable usb in ubuntu?  Why does windows have some of the best bootable usb creators while linux dosent?


Has there been any official (from the studio or owners) reason why we haven't seen a new Star Trek show set after Voyager?   So far every new Star Trek show or movie is around The Original Series or close to an already established show:   2009 Star Trek reboot - The characters from The Original Series. Star Trek: Discovery - After Enterprise but before The Original Series. Season 2 will have Spock. The  - Features obviously, Jean Luc Picard and takes place some time after Nemesis.   Why haven't we seen a show set years after Voyager  and we follow a new crew unrelated to any series?  --  I'm aware  question asks for any material set after Nemesis, but I'm looking for an official studio reason why we haven't seen a new completely separate Star Trek series after Voyager and Nemesis.

Star Trek: Discovery, the first new Star Trek television series in 12 years, debuted last week.  As with a number of recent Star Trek efforts, this is a prequel to the Original Series, occurring roughly one decade prior chronologically.    The Original Series, the Next Generation, Deep Space Nine, and Voyager occur in a chronological sequence that, generally speaking, moves forward (although TNG, DS9, and Voyager overlap to various degrees).  The linear trajectory of Star Trek productions took a sudden shift with the television series Enterprise, which was set just over 100 years before TOS. This was followed by J.J. Abrams' 2009 film Star Trek, which created a new timeline and which followed the characters from TOS, but at a time that is also chronologically one decade before TOS.  Given that the last few interpretations of Star Trek were prequels in one sense or another, I was disappointed that Discovery was yet another prequel.  I'd like to know why the showrunners decided to take this direction.  I haven't been able to find any statements about the rationale.    That being said, I find it interesting that Star Trek (2009) was set in 2255-2258 and Discovery is currently set in 2256, even though they are ostensibly in different timelines — the former in the reboot timeline and the latter supposedly in the original timeline.  Also, one of the showrunners for Discovery, Alex Kurtzman, was one of the principal members of the creative team behind the Abrams films.  Why did the creative staff behind Discovery decide to make another prequel?  Does it have anything to do with the fact that Star Trek (2009) and Discovery are set in roughly the same years?


My issue is little bit strange. I have an excel file in which some float values are mentioned e.g. 0.0079 but when I try to read it using my code it's giving me 0.007899999999999999.  I'm not sure what's actually happening here(may be that's the original data which was entered in the excel sheet when it was originally created). I checked other questions on SO which are similar but they are all concerned about 'how to not loose the precision' and my case is opposite.  sample code:  sheet_hdl = open_workbook('file.xls') sheet = sheet_hdl.sheet_by_index(0) for row_idx in range(1, sheet.nrows):     for col_idx in range(1):         if(val == str(sheet.cell(row_idx,col_idx + 1).value)):             accuracy_val = repr(sheet.cell(row_idx,col_idx + 7).value)             print(accuracy_val)   Note: It's not a duplicate of . The question in this link involves computation, but my data in excel doesn't involve any computations.

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


I was trying to post a comment on escaping backslashes, and ran into some formatting issues.  Namely, how to not escape backtick characters, because by default, they are always escaped following a backslash, regardless of the number of backslashes.  (repro'd in comment below)  This is despite the fact that backticks are not escaped in this way in posts: `\` generates \ as expected.   Backticks are tricky, so a workaround may be more useful than a fix. Unless, there are hideously more use cases than just regular expressions and questions about escaping strings?

I've noticed that in comments, when you create `code region` with backticks, the backslash will still work as an escape character within that region (but it should not, IMHO).  To clarify:   In comments, `\\` will be rendered as \, but it should be rendered as \\ In the post body itself, `\\` will be rendered as \\ (i.e., correctly)   This is especially confusing when you enter regular expressions into a comment, since backslash-escaping is very common there, and confusion increases if you are dealing with a regex that is double-escaped for representation in a string.   At some point you lose track how many backslashes you must make so the comment renders correctly, or you don't notice fast enough (or at all) and the comment contains wrong code where the same markup in a question or answer would come out as perfectly correct.   It's just that comments can't be corrected anymore after the grace period, leaving you with the choice of either deleting the comment, thus crippling the conversation, or engaging in a trial-and-error game of writing another comment with even more backslashes to explain the issue.  My question is two-fold:   Will this error be corrected? If yes, existing comments should probably be searched and "fixed" by a routine that tries to do the right thing (this is probably somewhere between hard and impossible) Or, can I rest assured that never ever the behavior of the backslash in comments is going to be changed, so I can start working around this issue by hand, knowing that they won't start displaying incorrectly at some point in the future?


I accidently delelted the partition lists (I did not write anything to the drive, just a simple delete using gparted.  I initially had partitions like so (if I remember correctly)    500 MB EFS 128 MB Windows Reserved Partition 178 GB Windows File System 270 GB empty space.. some other stuff??   I ran gpart, and it can find most of these partitions, but not the windows 128 MB reserved one. I tried to recreate the log using testdisk  But I cannot reboot into windows 10, I tried solutions listed  and none of them worked...  Is there a way to fix this through ubuntu live boot?

I have a Toshiba satellite A-200 laptop with a Vista OS on it with 4 NTFS partitions  (C:) Vista  (D:) Entertainment  (E:) Work  (F:) Sources   and I wanted to start using Ubuntu instead. So I tried it first from the live CD and everything was OK and all the partitions were shown and working and so I decided to install Ubuntu to replace Vista on the (C:) drive. After I did that I can no longer find my folders and files on the (D:), (E:), (F:) partitions and the only file system that is shown is one 198 GB although my HDD is 320 GB.  I can't access the lost data on the remaining 120 GB which I hope is still there and not totally lost  I am now working from the live CD but I am unable to install testdisk. Can I recover the Vista partitions by the product recovery CD to get my laptop back to the factory settings? Can I recover the NTFS partitions using a recovery program for Windows or will that make the problem worse?   I need these data badly as I don't have a backup for them.


I have a theoretical question, whether is it good practice to store files in the form of base64 in the database, or better save them physically on the disk and store path (indicator) to these files in the database?  I expect a theoretical explanation of the advantages and disadvantages of both practices. I must add that the size of these files is between 600kb and 3mb.  Thanks for any help

So I'm using an app that stores images heavily in the DB. What's your outlook on this? I'm more of a type to store the location in the filesystem, than store it directly in the DB.  What do you think are the pros/cons?


Files on my system renamed and file types also changed automatically on Windows 10. When I reasearched online I found that CTB Locker, ransomware are some of the viruses that do that. But I ran my system through Kaspersky, Malwarebytes, Eset Online scanner and they found nothing. I want to know to know what is doing this.   Running chkdsk returned nothing. Data recovery software Recuva, Easeus isnt helping either.  I want to know the root cause of this.  Anyone has any idea on this. Any help is appreciated.

What should I do if my Windows computer seems to be infected with a virus or malware?  What are the symptoms of an infection? What should I do after noticing an infection? What can I do to get rid of it? how to prevent from infection by malware?   This question comes up frequently, and the suggested solutions are usually the same. This community wiki is an attempt to serve as the definitive, most comprehensive answer possible. Feel free to add your contributions via edits.


May I know what does it mean when a '%' appears at the end of the output when I execute my code?   For example:   Hello,World%   Added:   I'm using Mac Os X iTerm2 zsh shell.  My code   echo 'Hello,World' | tr "\n" "\000"   I added the tr command to get rid of the newline at the end.   I'm using vim so I want to get the output without the newline just like if I'm using emacs.  Thank you.

I've noticed this on occasion with a variety of applications. I've often thought it was because the output was cancelled early (ctrl+c, for example) or something similar, and zsh is filling in a new line character. But now curiosity has gotten the best of me, since it doesn't seem to do this in bash.   zsh    bash    The Sequence program is something I pulled from a book while reading on Java certifications and just wanted to see if it would compile and run. I did notice that it does not use the println() method from the System.out package/class. Instead it uses plain old print().  Is the lack of a new line character the reason I get this symbol?


Let $a,b,c$ be positive reals, such that $\frac1a+\frac1b+\frac1c=a+b+c\ (\star)$, find the maximum of $\frac{1}{(2a+b+c)^2}+\frac{1}{(2b+c+a)^2}+\frac{1}{(2c+a+b)^2}$   This should be an application of Jensen's Inequality, so I have to find a concave function to maximize the sum, I thought to define;  $f(\frac1x):=\frac{1}{x+a+b+c},\quad\frac{\partial^2f(x)}{\partial x^2}<0$  so $f$ is concave and then the sum above is;  $f(\frac1a)+f(\frac1b)+f(\frac1c)$   using Jensen it should be less or equal to   $3\cdot f(\frac{\frac{1}{a}+\frac{1}{b}+\frac{1}{c}}3)=3\frac{1}{\left(\frac3{\frac{1}{a}+\frac{1}{b}+\frac{1}{c}}+a+b+c\right)^2}\overset{(\star)}=3\frac{1}{\left(\frac3{a+b+c}+a+b+c\right)^2}$  and the denominator can be minimized with AM-GM;  $\left(\frac3{a+b+c}+a+b+c\right)^2\ge\left(2\sqrt{3\frac{a+b+c}{a+b+c}}\right)^2=12$  so the result is $\frac14$, but it is wrong, where does it fail, maybe AM-GM value cannot be attained ?

Let a,b,c be positive real number, such that  $\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=a+b+c$. Prove that :  $\frac{1}{(2a+b+c)^2}+\frac{1}{(2b+c+a)^2}+\frac{1}{(2c+a+b)^2} \leq \frac{3}{16}$  Can anyone help me how to deal with it?


Which one is grammatically correct: "Nobody but them was present there." or "Nobody but they were present there."?

Can someone tell me how to make a sentence with "none but"?  None but they/them is/are responsible for it.


If my two neighbors own a cat, it’s "my neighbors’ cat". If someone famous owns a dog, what's the correct way to describe it: "someone famous’ dog"?

Suppose you wanted to place a possessive apostrophe in this sentence: Billy, who goes to my school, favorite game is tag.  I know it's not standard, but I can hear kids (or older) saying an s sound after "school" to make the possession clear. So I'd like to know if this could be written in the way that it's spoken (albeit not spoken in standard English).  Obviously, the sentence could be reworded, but that's not what I'm after.


It this game the score is set you 0 at the beginning and added to if you answer a question correctly, If i check the score by printing while I'm playing it gives the correct value but when the score is shown on the certificate it displays 0 no matter what.  Here's the code for the first file (The game part)  import pygame, time pygame.init() WHITE = ( 255, 255, 255) BLACK = ( 0, 0, 0) screen = pygame.display.set_mode((600, 600)) ButtonA = pygame.image.load("A.png") ButtonB = pygame.image.load("B.png") ButtonC = pygame.image.load("C.png") a = screen.blit(ButtonA,(50,400)) b = screen.blit(ButtonB,(250,400)) c = screen.blit(ButtonC,(450,400)) pygame.display.flip()  score = 0 if __name__ == '__main__':     for event in pygame.event.get():         if event.type == pygame.QUIT:             sys.exit()         if event.type == pygame.MOUSEBUTTONDOWN:             pos = pygame.mouse.get_pos()             if a.collidepoint(pos):                 screen.fill(BLACK)                 Correct = font.render("You are correct!", True, WHITE)                 Correct_rect = Correct.get_rect()                 Correct_x = screen.get_width() / 2 - Correct_rect.width / 2                 Correct_y = 150 - Correct_rect.height / 2                 screen.blit(Correct, [Correct_x, Correct_y])                 pygame.display.flip()                 score = score + 1                 print score                 time.sleep(2)   And here is the code for the part where it puts the value on a certificate which currently throws up nothing but the number 0  import pygame, sys, eztext from pygame.locals import * from eztext import Input #Importing the variable score from Question1Easy import score Name = self.value #Setting the variable score (an int) to a string Score = str(score)   How do I get the second file to grab the updated value of score instead of the static 0?

Given the following code, what does the if __name__ == "__main__": do?  # Threading example import time, thread  def myfunction(string, sleeptime, lock, *args):     while True:         lock.acquire()         time.sleep(sleeptime)         lock.release()         time.sleep(sleeptime)  if __name__ == "__main__":     lock = thread.allocate_lock()     thread.start_new_thread(myfunction, ("Thread #: 1", 2, lock))     thread.start_new_thread(myfunction, ("Thread #: 2", 2, lock))


I am trying to write a script that will output a table to a CSV.  The tricky part has been to get the output to only show the header once.  The script below does not show the header at all.  The other option we have used is is setting the pagesize extremely high.  That has also been very problematic.  set colsep | set pagesize 0 set trimspool on set linesize 10000   spool table1.csv SELECT host_name from v$instance; select to_char(sysdate, 'Dy DD-Mon-YYYY HH24:MI:SS') as "CURRENT TIME" from dual; prompt ================================================ prompt    TABLE 1 prompt    SELECT * FROM tbl1; prompt ================================================ SELECT * FROM tbl1; spool off   For clarity: I do not have direct access to the database.  I will be passing the script to a DBA to run against the database, so PL/SQL or anything else more advanced than a very basic script is probably not an option.  Also because of this, I want the column headers to show ONCE and only once whether there are 10 or 10 million records in the table.  This will give me reasonable descriptions of data that I need and minimize the cleanup before analyzing the data.

I need to retrieve certain data from an Oracle 11g release 1 database and provide it as one or more CSV files. The data resides in multiple tables and/or views. All this should work via the command line. What would be the best approach to this?


What is the command I ran and now I have no ubuntu left...  When I which the computer on, the monitor comes on, it goes passed the grub screen, it does not show anything after that.  How do I fix this?

I'd like to start over with my webserver and I'd like to reinstall all the LAMP packages, how do I do that?


Is it possible to add an additional static method to .Net string class so I could write:  var header = string.FormatHeader(str1,str2,str3,formatOption);

I'm a fan of extension methods in C#, but haven't had any success adding an extension method to a static class, such as Console.  For example, if I want to add an extension to Console, called 'WriteBlueLine', so that I can go:  Console.WriteBlueLine("This text is blue");   I tried this by adding a local, public static method, with Console as a 'this' parameter... but no dice!      public static class Helpers {     public static void WriteBlueLine(this Console c, string text)     {         Console.ForegroundColor = ConsoleColor.Blue;         Console.WriteLine(text);         Console.ResetColor();     } }   This didn't add a 'WriteBlueLine' method to Console... am I doing it wrong? Or asking for the impossible?


I was given  as an audit to 'first question' asked by a user. I wrote a (rather lengthy) comment that the question could be structured better by first stating the topic and the intent or question in words and asking how the follow-up conditions relate to it, and then giving the well-worded example(s) as they are. Then clicked "I'm done" - however I failed the audit - why? I stand by my asessment that the structure of the question is not ideal - despite it being a good question with all necessary information.  As such I'm not sure it's a good audit question.

I just failed these   in First Post, I read the question and thought it seemed reasonable but the user was deleted so to be on the safe side I clicked add comment and I failed the audit.  I'm not sure why adding a comment would be considered a negative action, is the correct option to click No Action Needed or edit?  What was I supposed to do in this situation?  Adding a comment should not be a review audit fail.


I need to create a buffer around a polygon.   I know how to do this, but my problem is I need the buffer to be 250 feet to the south, east, and west, but 500 feet to the north.   Is there any way to specify the distance of a buffer in a certain direction from a feature?

I want to create buffer polygon(with curved edges) from  points like this using ArcGIS for Desktop.   distance toward North from a point 5, toward South 1.5, toward west 1, toward East 2.   all this distance is attached as attribute in point in different fields.


I've written a program which writes one float value to one place past the end of an array. I have the code and the compiled binary file. Am I able to somehow determine if I'm lucky and the program will work forever?  The program we're talking about is for ESP8266.

I have heard about a buffer overflow and I would like to know how to cause one.  Can someone show me a small buffer overflow example? New(And what they are used for?)


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


I am working on an assignment converting English to Pig-latin. I am trying to get a word to go if the first letter is a then java should print the whole word.  When i type in apple it prints apple but if i put in cool it also prints out cool.   import java.util.Scanner; import javax.swing.JOptionPane;  public class Assignment_4_Piglatin{  public static void main(String[] args){  Scanner userWord = new Scanner(System.in);  System.out.println("K. Caleb Swallow"); System.out.println("Welcome to the Pig Latin Translator!");  boolean run = true; while(run){  System.out.println("Please enter a word(or press Q to quit):");  String firstLetter = "something"; String word = userWord.next();  System.out.println(word);  firstLetter = Character.toString(word.charAt(0));  String color = word;   if( firstLetter == "a"){ System.out.println(color);  }

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 work in internal, and I made a model shoot fire. For some reason it looks very low res. What can I do to fix this? an image has been attached:

So I took a sphere, made it a smoke simulator, added wind and increased that to 50.00, and rendered it. For some reason it looks very pixelated. 3D Viewport:   Final Render:   Blender File:


I have been working with the algorithm gdalogr:warpreprojectand have failed several times in the parameter in the title. Now, the problem is solved. It was about the EXTRA parameter. I read 3 books, and I know the explanation, but what I do not understand is the fact that it accepts an empty string. Furthermore, it ONLY accepts that empty string. My code is:   reproj = processing.runalg("gdalogr:warpreproject", raster, "EPSG: 25830", "EPSG:4326", '0', 0, 0, 0, 0, 2, 1, 1, False, 1, False, "", "G:\\pyQGIS\\MIRAR_COMP\\nuevo.tif")   Can anybody explain how does this parameter work?

I am having a hard time getting the "Additional Creation Parameters" to work when using GdalWarp through the processing toolbox.  I am trying to set the nodata value to 0 for the output raster.  processing.runalg("gdalogr:warpreproject","InRaster.tif","EPSG:32736","EPSG:32736",10,0,"-dstnodata 0","OutRaster.tif")   Has anyone used this functionality and managed to get it to work?


I noticed that when I paste a transparent image like this  in GIMP, it loses it's trasparency and is given a black background. Is there any way to disable that behaviour or at least prevent it?

On the latest version of GIMP on my PC, whenever I try to copy a transparent image from the internet, GIMP will automatically fill in the transparent areas with the background color I have selected.  This is a non-issue on my Mac, but I need to do this work on my PC, so how can I make it recognize the alpha of the image and not fill it with the background color?  The image canvas that I'm working with does have an alpha channel, but that does not seem to make a difference.


I'm trying to use Avenir Next with my Beamer presentation.   However, for the following MWE it switches back to the default beamer font.  MWE:  \documentclass[10pt]{beamer}  \usepackage{xltxtra} \setmainfont{Avenir Next LT Pro}  \usepackage{lipsum}  \begin{document}  \begin{frame}{Bla} \lipsum[1] \end{frame}  \end{document}   For other slides it sometimes also throws the error:     LaTeX Font Warning: Some font shapes were not available, defaults substituted.   Whereas it does work for a normal article class:  \documentclass{article}  \usepackage{xltxtra} \setmainfont{Avenir Next LT Pro}  \usepackage{lipsum}  \begin{document}  \lipsum[1]  \end{document}   Any thoughts to what could be going on?

I want to change font style in my presentation. I prefere Liberation Serif font. This is TrueType font so use XeLaTeX program. I tried to set this font using \usepackage{fontspec} and \setmainfont{Liberation Serif}, but font in my document does not change. How i can solve this problem?


When I type   sudo lshw -html > mySpecs.html   in my terminal, I get this in the HTML file:    Why is this red? Does that mean I`m missing some drivers?If it does,how can I install them for this version?(I went to Dell site,but they offer only Windows supported drivers)  Does that mean something is broken in my laptop?

I am checking list of devices installed in my system  I used the following   sudo lshw -html > ~/hardware.html   Many items come in red in that list, others come in a yellow color.  Does red mean there's something wrong with them?


I need to understand the relation between both these concepts with an example. I have an good understanding of Poisson distribution and it's applications. But I am having difficulties linking it to Poisson Process.

What is the most clever way to prove that the number of independent exponential summands in a fixed interval is distributed as a Poisson random variable? I can do it one way, but I would like to know if there is another way that gets more style points.  Let $S_1, S_2, \ldots \overset{iid}{\sim} \text{Exponential}(\mu)$. Just to be clear, the densities are each $f_S(s) = \mu e^{-\mu s}$.  Now, for $t > 0$, define $K_t = \{j : S_1 + \cdots S_j < t < S_1 + \cdots + S_j + S_{j+1}\}$.   The way I can do it is by directly integrating the joint density of the exponentials. For example,  $$P(K_t = 1) = P(S_1 < t < S_1 + S_2) = \int_0^t \int_{t-s_1}^{\infty} \mu e^{-\mu s_1}\ \mu e^{-\mu s_2}\ ds_2\ ds_1 = (\mu t) e^{\mu t}.$$  But is there another way?  Edit: This is a well-known result of basic Poisson processes. This fact was motivation for the question. So, ideally, answers won't rely on any results from Poisson or any other stochastic processes.


(1)In measuring time period of a pendulum, it is advised to measure the time between consecutive passage through the mean position in the same direction. This is said to result in better accuracy than measuring time between consecutive passage through an extreme position. EXPLANATION:  The speed near the extreme position is near zero and the decision by the observer that the bob has reached the extreme position may have some error due to slow movement. But the bob crosses the mean position with maximum speed so there is no hesitation in deciding that the bob has crossed the mean position and hence better accuracy(this was what i found when i googled it). (2)The time period of a particle in simple harmonic motion is equal to the time between consecutive appearances of the particle at a particular point in its motion. This point is ANS: At the extreme position because the particle is in the same phase at the consecutive appearance. Both the things look completely different. Which is correct OR are they both correct OR Is it the way i am thinking wrong ?. I don't understand it. Can anyone please explain it to me.

My physics textbook states that in measuring the time period of a pendulum it is advised to measure the time between consecutive passage though the mean position in the same direction. This results in better accuracy than measuring time between consecutive passage through an extreme position.  Why is one method of finding the time period better than the other? How can this affect the accuracy of the final result? I think it shouldn't make any difference, as the time taken for one full oscillation is independent of the choice of the start/end point. Is the statement in the book really correct?


I could get a sample class to automatically deactivate inactive users in Salesforce and did some changes to it:      public class DeactivateInactiveUsers implements Schedulable {     public void execute(SchedulableContext context) {         User[] selectedUsers = [SELECT Id FROM User WHERE IsActive = TRUE AND Id NOT IN (SELECT UserId FROM LoginHistory WHERE LoginTime = LAST_N_DAYS:365) AND Z_Profile_Text__c = 'BR Marketing' AND Z_Profile_Text__c <> 'System Administrator' AND Z_Profile_Text__c <> 'API-Only'];         for(User record: selectedUsers) {             record.IsActive = false;         }         Database.update(selectedUsers, false);     } }   Now I have the "big"challenge to create a test class to deploy this class to production. Could anyone give some assistance on this?  Thank you

This is a canonical question and answer developed by the community to help address common questions. If you've been directed here, or your question has been closed as a duplicate, please look through the resources here and use them to shape more specific questions. To browse all canonical questions and answers, including more unit test resources, navigate to the  tag.  This canonical question is intended to address several classes of common questions by providing a quick summary and links to comprehensive resources:   How do I start writing my first unit test?  How do I unit test this code?  I need help writing this unit test.   Salesforce Stack Exchange looks for detailed, specific questions that the community can help you with, and can't write tests on your behalf. We feel that working with the resources below can help you get started, and we encourage you to make an attempt to write your test and return to SFSE with your specific questions when you encounter challenges you can't resolve.


so, if I am correct and there is not any real orientation in space such as, up,down, left, and right. And people agree that the universe is inflating or getting bigger. so if there is no orientation in space how can we be certain that the universe isn't expanding,... but moving through its own individual space and we are just along for the ride.

Does space expand equally in every direction, so that it draws a perfect sphere or is expansion asymmetric, so it creates "bubbles" (when seen from the outside)?


I have an USB from which I want to install my OS (Windows 10). Once that's done, I install VS, Notepad++, Paint.NET, SQL Studio and a lot of other stuff that's nice to have.  All the stuff, I install manually after the OS installation's completed. Then, we also have all the settings and other stuff.  I wonder, is it easily possible to create such an USB installation drive as I have now but with the addition that all the stuff I want added and all the settings that I've done, are included?  The I'm-loving-it scenario would be if I can put my thing into a hole and after a short while get a computer that's freshly reinstalled with all the stupid stuff I might have done gone.  After that I only need to worry about backing up the genius stuff I surely have done...

I was wondering if it was possible to make a bootlable image of a Windows 7 Pro OEM Installation CD that I have and put it on an USB stick for faster/easier installation. I am asking because we have a couple of PC´s where I´d have to install the OS using the same key (MAK).  Also is it possible to kind of populate that image with software that would have to be installed anyways on all machines (like Chrome, Outlook, etc)?  It would be really helpful to just install a Windows 7 image with customized software already installed. I would just make an image of an OS and use that, but the hardware of the machines differ.


I am taking an online class on algorithms and I had the following quiz. I got it wrong and am trying to understand the reason for the answer.  Which of the following is O(n^3)? a) 11n + 151 gn + 100 b) 1/3 n^2 c) 25000 n^3 d) All of the above.  The correct answer is (d) all of the above. The reason is that Big-O notation provides only the upper bound on the growth rate of function as n gets large. I am not sure why the answer is not (c). For example, the upper bound on (b) is less than n^3.

Sometimes I see Θ(n) with the strange Θ symbol with something in the middle of it, and sometimes just O(n). Is it just laziness of typing because nobody knows how to type this symbol, or does it mean something different?


I have done quite a lot of research on how to swap the Escape and Caps Lock keys. I achieved it while using X11 via my .xinitrc file and the following line of code: setxkbdmap -option caps:swapescape However, when I start a tty, it doesn't work. How can I get this to work while using a tty? Is it possible to use some kind of global option, like a custom keyboard layout that does not depend on X11? I'm using Arch Linux, if that helps.

I'm looking for a way to swap Esc and Caps Lock on Linux virtual console.  In X11, I can do this with setxkbmap -option caps:swapescape, but I don't know an equivalent in text mode. So, what can I do?


I have a script that dynamically creates Amazon EC2 instances and adds their ssh key to my ~/.ssh/known_hosts. However, whenever I need to refresh the instance by terminating and recreating it, I get obnoxious warning messages like:  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that a host key has just been changed. The fingerprint for the ECDSA key sent by the remote host is <fingerprint>. Please contact your system administrator. Add correct host key in ~/.ssh/known_hosts to get rid of this message. Offending ECDSA key in ~/.ssh/known_hosts:94   remove with: ssh-keygen -f "~/.ssh/known_hosts" -R <hostname> Password authentication is disabled to avoid man-in-the-middle attacks. Keyboard-interactive authentication is disabled to avoid man-in-the-middle attacks.   The warning is understandable, but even if I run that command to remove the old key, logging in still gives me the warning:  Warning: Permanently added '<hostname>' (ECDSA) to the list of known hosts. Warning: the ECDSA host key for '<hostname>' differs from the key for the IP address '<ip>' Offending key for IP in ~/.ssh/known_hosts:96   The solution is to manually remove that line in my known_hosts, but is there a way to automate this by running a single command beforehand?

This is a simple issue that we all face and probably resolve manually without giving much thought.   As servers change, are re-provisioned, or IP addresses reallocated, we receive the SSH host verification message below. I'm interested in streamlining the workflow to resolve these ssh identification errors.   Given the following message, I typically vi /root/.ssh/known_hosts +434 and remove (dd) the offending line.   I've seen developers/users in other organizations delete their entire known_hosts file out of frustration in seeing this message. While I don't go that far, I know there's a more elegant way to handle this.   Tips?  [root@xt ~]# ssh las-db1  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that the RSA host key has just been changed. The fingerprint for the RSA key sent by the remote host is ed:86:a2:c4:cd:9b:c5:7a:b1:2b:cc:42:15:76:8c:56. Please contact your system administrator. Add correct host key in /root/.ssh/known_hosts to get rid of this message. Offending key in /root/.ssh/known_hosts:434 RSA host key for las-db1 has changed and you have requested strict checking. Host key verification failed.


I am trying to set different margins for the first page of my document. As I am not sure about the content of the first page, the \afterpage command has been used to achieve the required effect. However, I have noticed that the first paragraph on the second page (the red ellipse on top of Page 2) still has the margins of the first page (please check the example below).    Is there any way where I can force the new margins on the entire content of the second page? Starting from the second page, is there a way where I can have a grey rectangle (Page 2 and Page 3 currently are drawn by hand only to demonstrate what I am after) covering the entire wide margin of the page (edge-to-edge vertically and edge-to-text on the wide margin horizontally)?  \documentclass[11pt,a4paper,twoside]{article}  \usepackage{lipsum,afterpage}  \usepackage[left=1.5cm, top=1.5cm, right=3cm, bottom=1.5cm, nohead, nofoot]{geometry}  \begin{document}  \newgeometry{left=7.5cm, top=1cm, right=1cm, bottom=1cm}  \afterpage{\globaldefs=1 \restoregeometry}  \lipsum\lipsum\lipsum  \end{document}    Thank you.

in some (very rare) cases, it might be desirable to have the type area, particularly the text width, be different on even and odd pages. Let's say we're typesetting a textbook that's supposed to have small illustrations or annotations in the margin of the odd pages -- so we'd need a narrower type area on these. Like this:   Here's an attempt at a solution I came up with. It isn't as smart as I thought it was. I thought we might just combine everyshi and an \ifthispageodd test to change the typearea at every shipout. Obviously, that's not how it works:  \documentclass[paper=a5,pagesize,10pt,DIV=12,twoside=true]{scrreprt} \usepackage{everyshi,blindtext} \EveryShipout{% \ifthispageodd{\areaset{6cm}{12cm}}{\areaset{9cm}{12cm}}}  \begin{document} \Blinddocument \end{document}   this results in:  ! Bad space factor (0). <recently read> \@savsf   l.7 \Blinddocument   Is there a way to improve this? Or something entirely different?


I created a batch file which stops a service,then stops a process and then starts the service it stopped.  When I execute the batch file, it says "access denied". I cannot figure out why it says access denied because I am an Administrator. I searched everywhere for a solution to this with no luck.  Here are my command lines within the batch file:  net stop uvnc_service taskkill /f /im winvnc.exe net start uvnc_service   Note: When I right click on it, I can say "run as administrator" which then works, but I created a task in task scheduler which executes the batch file every 5 minutes and I cant right click and say "run as administrator" every 5 minutes.  Also in the properties of the batch file under the compatibility tab, "run as administrator is greyed out so I cant check it.  How can I automatically run the batch file as administrator every 5 minutes?  Is there maybe a command line I can insert into my batch file that runs it as administrator every time?

On Linux, we can use  sudo bash   to run a shell as the superuser.  On Windows 7, we can use     Start menu -> (in search box, type) cmd -> Right click on search result and choose Run as Administrator   to run a command prompt as an administrator. Is there also a command prompt line that is like Linux's sudo or su so as to start a shell as an administrator?


I've been trying to uninstall and reinstall MySQL on Ubuntu 16.04, I've seen plenty of methods but I can't figure out why I'm getting an error.  $ sudo apt-get install mysql-server mysql-server is already the newest version (5.7.17-0ubuntu0.16.04.2). The following package was automatically installed and is no longer required:   snap-confine Use 'sudo apt autoremove' to remove it. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 2 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n]  Setting up mysql-server-5.7 (5.7.17-0ubuntu0.16.04.2) ... Renaming removed key_buffer and myisam-recover options (if present) Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details. invoke-rc.d: initscript mysql, action "start" failed. ● mysql.service - MySQL Community Server    Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)    Active: activating (auto-restart) (Result: exit-code) since Mi 2017-04-26 12:15:04 EEST; 5ms ago   Process: 13693 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=1/FAILURE)  apr 26 12:15:04 alex-X750JB systemd[1]: Failed to start MySQL Community Server. apr 26 12:15:04 alex-X750JB systemd[1]: mysql.service: Unit entered failed state. apr 26 12:15:04 alex-X750JB systemd[1]: mysql.service: Failed with result 'exit-code'. dpkg: error processing package mysql-server-5.7 (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of mysql-server:  mysql-server depends on mysql-server-5.7; however:   Package mysql-server-5.7 is not configured yet.  dpkg: error processing package mysql-server (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                                                                                Errors were encountered while processing:  mysql-server-5.7  mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1)   I've tried these steps:  sudo apt-get purge mysql* sudo apt-get autoremove sudo apt-get autoclean sudo apt-get dist-upgrade sudo apt-get install mysql-server   Everything goes well, until I use sudo apt-get install mysql-server  If I run systemctl status mysql.service:  ● mysql.service - MySQL Community Server    Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)    Active: inactive (dead) (Result: exit-code) since Mi 2017-04-26 13:30:19 EEST; 11min ago   Process: 17650 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=1/FAILURE)  apr 26 13:30:18 alex-X750JB systemd[1]: Failed to start MySQL Community Server. apr 26 13:30:18 alex-X750JB systemd[1]: mysql.service: Unit entered failed state. apr 26 13:30:18 alex-X750JB systemd[1]: mysql.service: Failed with result 'exit-code'. apr 26 13:30:19 alex-X750JB systemd[1]: mysql.service: Service hold-off time over, scheduling restart. apr 26 13:30:19 alex-X750JB systemd[1]: Stopped MySQL Community Server. apr 26 13:30:19 alex-X750JB systemd[1]: mysql.service: Start request repeated too quickly. apr 26 13:30:19 alex-X750JB systemd[1]: Failed to start MySQL Community Server.

My overall upgrade went well, but I am left with a critically lingering issue of mysql-server not being able to install itself, and nothing I am trying gets it to work.  This is the error I see when trying to install/reinstall it:  Setting up mysql-server-5.7 (5.7.11-0ubuntu6) ... Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details. invoke-rc.d: initscript mysql, action "start" failed. dpkg: error processing package mysql-server-5.7 (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of mysql-server:  mysql-server depends on mysql-server-5.7; however:   Package mysql-server-5.7 is not configured yet.  dpkg: error processing package mysql-server (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                    Processing triggers for systemd (229-4ubuntu4) ... Processing triggers for ureadahead (0.100.0-19) ... Errors were encountered while processing:  mysql-server-5.7  mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1)   I've tried completely removing it, though doing so attempts to install MariaDB because of dependencies (?). Any suggestions on what I can do to fix this would be most welcome.  EDIT: Looks like I'm not the only one:


A simple question :  1) In Python using numpy, how to get without parisitic decimals the follwing result (true value 0.6968) ? :  >>> 0.67*(1.04) 0.6968000000000001   If I convert to string, I can find the right value :   >>> str(0.67*(1.04)) '0.6968'   2) By the way, how to control the rounding to systematically get the real value ? I saw that epsilon machine with Python (and/or Numpy) was around 2e-16.  So, I conclude that taking 16 decimals is too small and implies random values after 16th decimal or more precisely below 2e-16.  I don't want to troll but Matlab (I like also Python) doesn't produce this kind of error.

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


I'm using tomcat6 on an ubuntu server. I have a problem with Java. It looks like it doesn't take the timezone information from the operating system. I used tzselect command to update my timezone and I've also added that line to my .profile file:  TZ='Europe/Istanbul'; export TZ   However, while date command gives this output:  Tue Jul 22 17:20:31 EEST 2014   My tomcat logs are printed with this date:  10:20:30,006 INFO  [StatsServiceImpl    ] - runSaveStatsTask::FINISHED::DATE::7/22/14 10:20 AM   Where can I configure timezone settings which are used by jvm?

I am running a Tomcat application, and I need to display some time values.  Unfortunately, the time is coming up an hour off.  I looked into it and discovered that my default TimeZone is being set to:  sun.util.calendar.ZoneInfo[id="GMT-08:00",                            offset=-28800000,                            dstSavings=0,                            useDaylight=false,                            transitions=0,                            lastRule=null]   Rather than the Pacific time zone.  This is further indicated when I try to print the default time zone's , and it comes up "GMT-08:00", which seems to indicate to me that it is not correctly set to the US Pacific time zone.  I am running on Ubuntu Hardy Heron, upgraded from Gutsy Gibbon.  Is there a configuration file I can update to tell the JRE to use Pacific with all the associated daylight savings time information?  The time on my machine shows correctly, so it doesn't seem to be an OS-wide misconfiguration.    Ok, here's an update. A coworker suggested I update JAVA_OPTS in my /etc/profile to include "-Duser.timezone=US/Pacific", which worked (I also saw CATALINA_OPTS, which I updated as well). Actually, I just exported the change into the variables rather than use the new /etc/profile (a reboot later will pick up the changes and I will be golden).  However, I still think there is a better solution... there should be a configuration for Java somewhere that says what timezone it is using, or how it is grabbing the timezone. If someone knows such a setting, that would be awesome, but for now this is a decent workaround.    I am using 1.5, and it is most definitely a DST problem.  As you can see, the time zone is set to not use daylight savings.  My belief is it is generically set to -8 offset rather than the specific Pacific timezone.  Since the generic -8 offset has no daylight savings info, it's of course not using it, but the question is, where do I tell Java to use Pacific time zone when it starts up?  I'm NOT looking for a programmatic solution, it should be a configuration solution.


When I use a vector within the text, the vector appears too big - how can I make it smaller?  Example:  \documentclass[12pt]{scrartcl} \usepackage{amsmath} \usepackage{amssymb} \begin{document} One standard basis vectors of $\mathbb{R}^2$ is \begin{pmatrix}1\\0\end{pmatrix}$.  Unfortunately, the vector is about twice as tall as the rest of the line.  How can I reduce its size to about $1.5$-times the size of the line? \end{document}

How do we add a matrix to a LaTeX document?


I'm trying to substitute a specific word that has a newline(mainly using sed), but while trying different things to do so, it seems to not have worked... Here the test input/file: this # target for substitution this is a test another test?  And here are the things i tried: sed 's/^this/test/' testfile  But this work on the other "this" word too (instead of just the one with the newline) sed 's/^this\n/test/' testfile  Here i added a \n but while this sometimes works with sed, it doesn't in this case. Finally, I also tried using word bondaries with \b, but that didn't work either: sed 's/\bthis\b\n/test/' testfile  Any way to do this? (specifically with sed if possible).

I'm looking for a way to only execute replacement when the last character is a newline, using sed.  For instance:  lettersAtEndOfLine   is replaced, but this is not:  lettersWithCharacterAfter&   Since sed does not work well with newlines, it is not as simple as  $ sed -E "s/[a-zA-Z]*\n/replace/" file.txt   How can this be accomplished?


I'm doing my project in visual studio 2015 community version.  I want to create two class.  class A {     B* b;     public:     //several method...  }; class B : public A {     public     //several method... };   Is this possible?  I keep receive error code C2504. But I cannot translate this error message to English.  I'm sorry that I don't show this error message.    Two class are separated and each class .h file include others .h file For example, include "B.h" in A.h and vice versa.    I'm sorry I forgot adding semicolon.

I am looking for the definition of when I am allowed to do forward declaration of a class in another class's header file:  Am I allowed to do it for a base class, for a class held as a member, for a class passed to member function by reference, etc. ?


I installed Ubuntu 3 years ago and an upgrade attempt failed. The disk was configured dual-boot with Ubuntu + Windows.   I tried to install an ISO file for Ubuntu 16.  How can upgrade my previous Ubuntu installation to Ubuntu 16 without losing the dual-boot or Windows!?

What are the different ways I can use to upgrade Ubuntu from one release to another?


If I had a plain-text file containing 8 million lines and I want to print out lines 4,000,010 to 4,000,000 to the screen, which would be more efficient: awk or sed?  There is no pattern to the text, and unfortunately, a database isn't an option. I know this isn't ideal, I'm just curious on which one would complete the task quicker.  Or maybe there is even a better alternative to sed or awk?

Say I have a huge text file (>2GB) and I just want to cat the lines X to Y (e.g. 57890000 to 57890010).  From what I understand I can do this by piping head into tail or viceversa, i.e.   head -A /path/to/file | tail -B   or alternatively  tail -C /path/to/file | head -D   where A,B,C and D can be computed from the number of lines in the file, X and Y.  But there are two problems with this approach:   You have to compute A,B,C and D. The commands could pipe to each other many more lines than I am interested in reading (e.g. if I am reading just a few lines in the middle of a huge file)   Is there a way to have the shell just work with and output the lines I want? (while providing only X and Y)?


$X$ and $Y$ are iid r.v.s where $f(x)=\lambda e^{-\lambda x}$, $x>0$. We are given $Z=X/Y$ and asked to find the CDF and density for $Z$.  I tried doing this using the multivariate transformation formula, where   $f_{W_1,W_2}(w_1,w_2)=f_{X_1,X_2}(x_1,x_2)|J|$, but I ended up getting that $f_Z(z)=\frac{1}{(1+z)^2}$, which results in a negative CDF. I was hoping to see a different method of doing this. Any help appreciated.  Edit: Here is my work for obtaining my answer:  $Z=X/Y$; we then let $W=Y$ and $X=ZW$. The Jacobian is then calculated to be $w$. That means we have:  \begin{align} f_Z(z) & =\int_0^\infty f_X(x)f_Y(y)w\,dw \\[10pt] & =\int_0^\infty \lambda e^{-\lambda x}\lambda e^{-\lambda y}w \, dw \\[10pt] & =\lambda^2 \int_0^\infty e^{-(z+1)\lambda w}w\,dw \\[10pt] & =\frac 1 {(z+1)^2} \end{align}

Let $X$ and $Y$ be independent exponential variables with rates $\alpha$ and $\beta$, respectively. Find the CDF of $X/Y$.  I tried out the problem, and wanted to check to see if my answer of: $\frac{\alpha}{ \beta/t + \alpha}$ is correct, where $t$ is the time, which we need in our final answer since we need a cdf.  Can someone verify if this is correct?


Let $A \in \mathbb{R}^{n, n}$, $B \in \mathbb{R}^{n, m}$, $C \in \mathbb{R}^{m, n}$ and $D \in \mathbb{R}^{m, m}$ be matrices. Now, I have seen on Wikipedia the  of why determinant of $\left[\begin{matrix} A & 0 \\ C & D\end{matrix}\right] = \det{A}\cdot \det{D}$, but I still did not get it. Specifically, the explanation is:  This can be seen ... from a decomposition like: $\left[\begin{matrix} A & 0 \\ C & D\end{matrix}\right] = \left[\begin{matrix} A & 0 \\ C & I_{m}\end{matrix}\right]\left[\begin{matrix} I_n & 0 \\ 0 & D\end{matrix}\right]$  I understood that the equation is true from the standard rules of matrix-matrix multiplication, but it is still not too clear why this should prove what we want to prove or show. If $A$, $B$, $C$ and $D$ were regular reals (and $I_{i}$ was $1$), then the equation and the explanation would be obvious, because of the standard rules of calculating determinants... But in this case, I cannot understand why the equation shows that the final determinant is $$\det{A} \cdot \det{D}$$ Those 2 matrices $\left[\begin{matrix} A & 0 \\ C & I_{m}\end{matrix}\right]$ and $\left[\begin{matrix} I_n & 0 \\ 0 & D\end{matrix}\right]$ basically could not be triangular or diagonal matrices, from my understanding...

I am given the following partitioned, upper-triangular matrix:  $$ \begin{bmatrix}   A_1 &*  &*  &*  &*  &*  \\    0& A_2 &*  &*  &*  &*  \\    .&  0& A_3 &*  &*  &*  \\    .&  0&  0 &...  &*  &. \\    .&  0&  0&  0& ... &.  \\    0&  .&  ...&  0&0 & A_m \end{bmatrix} $$  where each of the $A_i$ are block-matrices.  I have to prove that the determinant of this general matrix is: $$ \prod_{n=1}^m \det A_i. $$  We already proved in class that it is true for $ m=2 $ and we can use it in our proof.  Thanks for your answers!


I'm a new dm and i'm starting my first game, and I was hoping I could find some pointers on what things I should put on my dnd screen. General tips would be good too!

The question is, what elements on a DM screen are essential? I'm new at playing and DMing, altough a lot of experience watching games, just got a group to play with now. Started with the starter set in 5E and the Lost Mine of Phandelver adventure, however I've noticed the game can come to a stop when checking the rules or how to do something, while getting the books and stuff like that. So I thought to make a DM screen with some cheat sheets, of the most usual things new players, and new DM's have doubts on, and how to make the game flow well without long rule-checking breaks. What are the essential things to have on that screen? So far this is what I found  but not sure if it has all I need or so much stuff that'll also make the game stop a lot while cheking it out.


Here's the rendered image. The problem is with the shadows on the green object's right side. It's like a weird wave shaped shadow. And I get this result in all my renders where I use subsurf and smooth shading. I don't know if it has anything to do with them. Help if you can, please.  Many thanks  I've tried a few changes based on the two links, but it's still the same. So gandalf3, it's not the same question, the problem is different, as it seems.

I wonder if this is a bug, or if I missed something... When a light hits tangentially convex surfaces with "smooth shading", the shadow on this surface seems to "partially ignore" the smoothness of the surface. Here is an example with a simple cylinder :    On the left, a cylinder with "flat shading". Everything's ok. On the right, the same with "smooth". We can see an edge, bad shadowed.  With or without the "Edge split" modifier, no matters, the edge is still there. The shader is a simple white diffuse shader with no texture nor displace.  I have to add a subsurf modifier with at least 2 levels, which will insanely increase the vertex count... And I can't do that for my project.  I hope someone already saw it, and have a little tip to share. Or if someone already know it's a bug, or a limit of the current Cycles renderer ?


In my activity I can drag the dot all over the screen. Once I press the Back button and then come back again to the activity the dot position isn't saved.. what should I do?  private ImageView map; private ImageView dot;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.map_layout);     map = (ImageView) findViewById(R.id.map);     dot = (ImageView) findViewById(R.id.dot);     MotionReceiver tc = new MotionReceiver();     LocalBroadcastManager.getInstance(this).registerReceiver(tc, new IntentFilter(Constants.TEXT_MOVEMENT)); }  @Override public void onSaveInstanceState(Bundle savedInstanceState) {     super.onSaveInstanceState(savedInstanceState);     savedInstanceState.putFloat("X", dot.getX());     savedInstanceState.putFloat("Y", dot.getY()); }  @Override public void onRestoreInstanceState(Bundle savedInstanceState) {     super.onRestoreInstanceState(savedInstanceState);     dot.setX(savedInstanceState.getFloat("X"));     dot.setY(savedInstanceState.getFloat("Y")); }

I've been working on the Android SDK platform, and it is a little unclear how to save an application's state. So given this minor re-tooling of the 'Hello, Android' example:  package com.android.hello;  import android.app.Activity; import android.os.Bundle; import android.widget.TextView;  public class HelloAndroid extends Activity {    private TextView mTextView = null;    /** Called when the activity is first created. */   @Override   public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);      mTextView = new TextView(this);      if (savedInstanceState == null) {        mTextView.setText("Welcome to HelloAndroid!");     } else {        mTextView.setText("Welcome back.");     }      setContentView(mTextView);   } }   I thought it would be enough for the simplest case, but it always responds with the first message, no matter how I navigate away from the app.  I'm sure the solution is as simple as overriding onPause or something like that, but I've been poking away in the documentation for 30 minutes or so and haven't found anything obvious.


I know that $g\in L^1[a,b]$ implies that $g<\infty$ almost everywhere. It seems like it should follow that $g$ is bounded almost everywhere, but I can't think of a proof or a counterexample.

I am looking for an Integrable function $f : [0,1] \to \mathbb{R}$ which is not essentially bounded on any subinterval of $[0,1]$.  Thank you in advance.


I'd like to embed an online map inside of a Word document for my geography task in school. I have the code for an iframe of a map at www.arcgis.com.  How do I insert it in the document? I'm using Word 2013.

All,  Is there any way of embedding a webpage in a MS Word 2007 document, similar to having an iFrame object in the Word doc, with any changes to the underlying webpage being updated as appropriate?  Many thanks for any help on this


I am trying to configure the AWS CLI using a bash script. I have the below in my script and it will not set the values. When I echo out the variables names it just shows a blank line.  script code  export AWS_ACCESS_KEY_ID=<key>  export AWS_SECRET_ACCESS_KEY=<secret_key>  export AWS_DEFAULT_REGION=<region>

I have multiple Amazon EC2 accounts and want to quickly be able to switch variables, such as $EC2_HOME, using a script.  I have have a shell script set up like this:  #!/bin/sh export EC2_HOME=/home/me/.ec2 echo $EC2_HOME   When I run the script I know that EC2_HOME is set, but I thought that using export would make the variable stick around after the script completed. It does not, as running echo $EC_HOME does not show anything.  I know this must be very rudimentary Linux scripting knowledge, but I don't know it. I tried looking for related questions without luck - so my apologies if this is a duplicate.


I was told that even if you hold 3 gyms you still get 500 Stardust, though you do get 30 coins. Since I've been unable to  control more than one gym at a time, I've been unable to confirm this.   Does having more gyms equate to more stardust?

So far, gyms in my area flip so frequently that I haven't been able to hold more than one gym at a time when collecting my rewards. I know the reward for a single gym is 500 stardust and 10 coins.   Does this reward scale linearly with multiple gyms, or does it follow a different progression? I've also heard there might be some kind of bonus for holding a gym for more than a day, but haven't managed to do it. Is there a bonus for that (or any other kinds of bonuses)?


When ever I am playing Xbox it randomly signs me into Xbox live then later will sign me out of Xbox live and I don't know how to fix this little issue. If anyone knows the answer it would be much appreciated if you could help me out.

Whenever I start a game, from both the disc and hard drive, my Xbox will say "Username signed out". What's wrong and how do I fix it? Just to be clear, it signs me out when I start a game. How can I stop this?


I have a list of  three string like:   text_list=['I think, ] + {F uh, } I wonder ] if that worked + {F uh, } say. /','You might try, {F uh, }  /','I dont know' ]   I want to count {F uh, } using regular expression and count its frequency for each string in text_list. Here is my code:  filler_dic=dict() pattern = re.compile('\{F\s.+\}') for line in text_list:       if(pattern.search(line)):             res=sum(1 for m in re.finditer(pattern, line))             filler_dic[line]=res       else:            filler_dic[line]=0   For first string in list there are two {F uh,} so  it should give two but its giving 1.  Can anyone help and suggest some solution.

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


How can I remove an item from a JavaScript object?  Like this:  var test = {'red':'#FF0000', 'blue':'#0000FF'}; test.remove('blue');

Say I create an object as follows: let myObject = {   "ircEvent": "PRIVMSG",   "method": "newURI",   "regex": "^http://.*" };  How should I remove the property regex to end up with new myObject as follows? let myObject = {   "ircEvent": "PRIVMSG",   "method": "newURI" };


Let f be a continuous function on the interval [0,1], which is differentiable on (0,1).   I know that I will have to use the definition of a derivative, which is the limit as x approaches 0 f(x)-f(0)/(x-0)

Suppose we have a continuous function $f : \mathbb{R} \to \mathbb{R}$. Suppose also that for a certain point $c$, $\lim_{x \to c} f'(x)$ exists. Must $f'(c)$ exist as well, and be equal to this limit?  This isn't quite the same as asking if derivatives are always continuous. The well-known function $f(x) = x^2 \sin (1/x)$ is continuous and differentiable everywhere, but its derivative has no limit at $x = 0$. I'm wondering if the derivative of a continuous function can have a discontinuity where its limit does exist.


when I try to write 90% I do 90 $%$ , but none works and anything after the % doesn't print in the output, any solution ?

I need to output the below text but since \ is a special character, I cannot:  [RegularExpression(@"\d+")]   Also sometimes I need use dollar sign $ as well but it seems to be a special char, too.  What is the way to escape those in LaTeX?  UPDATE:  I used \verb as suggested but I am unable to run commands inside it. Also, in the output the font and the opacity of the text is different than the default one:  \verb|[RegularExpression(\newline @"\d+")]|


I'm transitioning from Windows 10 to Ubuntu 20.04.2 LTS and in Ubuntu I want to work with React Native expo framework which is a framework for hybrid mobile development. I have been struggling to find a proper tutorial to install the expo cli for react native in Ubuntu and have been following a Russian tutorial but I do not know any Russian so just using common sense to guide me soo far.  this is the tutorial I'm following but at 3:10 mark of the video, I have no idea how he got that screen which those checkboxes and i do not understand what they mean either. While testing out different methods to bring the screen up I  mistakenly opened up this and entering the command "^X" followed by the enter key did not work. It just send me to the next line. So how should I escape this screen ? Picture of where I'm stuck:

As it required root access to edit, I've opened a init.txt file using sudoedit, but I don't see how to save my changes. I also see lots of things like ^X instructions at the bottom of the terminal which I'm clueless about.


The geometrical proof is simple, but I want to know how to prove $\pi \gt 3$ by using basic calculus?

$\pi\approx 3.141592654$   Why is it so close to $3$?   I find this intriguing, this cannot be a coincidence.


I am looking into flights from Tokyo to Bogotá. The layover is in ATL - Hartsfield-Jackson. Do I need to go through immigration and customs if I am not going to stay in ATL or the US? Both flights with same airline, KLM.

I have been checking for similar questions for the past 2 hours but I could not find a reply. I am really sorry if this has been asked before.  With the following itinerary:  Cancun, Mexico (CUN) to New York, USA (JFK) JFK to Rome, Italy (FCO)  As an Italian passenger, do I have to pick up my luggage in JFK and clear customs or not?


I have to upgrade Ubuntu server 10.04 to 12.04.  10.04 is not supported any more. So what step I have to do, for a clean upgrade?  I did the following steps:  sudo sed -i -re 's/([a-z]{2}\.)?archive.ubuntu.com|security.ubuntu.com/old-releases.ubuntu.com/g' /etc/apt/sources.list  sudo apt-get update && sudo apt-get dist-upgrade  sudo apt-get update  sudo do-release-upgrade   After some time, the upgrade is aborting: ...Restoring original system state  root@vupapzimbra01:~# sudo apt-get install update-manager-core Reading package lists... Done Building dependency tree Reading state information... Done update-manager-core is already the newest version. The following packages were automatically installed and are no longer required:   linux-headers-2.6.32-41-server linux-headers-2.6.32-41 Use 'apt-get autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. root@vupapzimbra01:~#   root@vupapzimbra01:~# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 10.04.4 LTS Release:        10.04 Codename:       lucid  Get:51 http://us.archive.ubuntu.com precise/restricted Translation-en [2395 B] Get:52 http://us.archive.ubuntu.com precise/universe Translation-en [3341 kB] Fetched 19.9 MB in 6s (1873 kB/s)  Checking package manager Reading package lists... Done Building dependency tree Reading state information... Done Building data structures... Done  Calculating the changes  Calculating the changes  Error authenticating some packages  It was not possible to authenticate some packages. This may be a transient network problem. You may want to try again later. See below for a list of unauthenticated packages.  accountsservice apparmor . . wpasupplicant xkb-data   Restoring original system state  Aborting Reading package lists... Done Building dependency tree Reading state information... Done Building data structures... Done  === Command detached from window (Thu May  4 09:20:53 2017) === === Command terminated with exit status 1 (Thu May  4 09:20:53 2017) ===

Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


I just put windows 7 on my work laptop and im setting it all up like it used to be. But i cant remember what option i changed to stop my internet traffic being tunneled over the VPN connection. I only want to connect to exchange and intranet over VPN.

I want to use a Windows VPN but only for a particular network, so that it doesn't take over my entire network connection.  e.g., Instead of the VPN becoming the default route, make it only the route for 192.168.123.0/24  (I can see that there is a solution for this for Ubuntu , but sometimes I have to do this on Windows too)  Can this be automated so that whenever I connect to the VPN it does this?


I can't log in to my system. At first I had gotten the following error:   cryptsetup: unknown fstype, bad password or options?   Ubuntu spammed this at boot.   Now I can't run the Ubuntu OS installed on that drive at all. All I get is error spam for invalid images and invalid image headers.  When I use a live USB to try to access the files, I can decrypt the drive, but I still can not log in to my system normally.  Aside from the live usb, I can't access it. and even then with the live usb it's difficult; I had to download nemo and open a window with root permission to access my files.

I activated disk encryption for my Ubuntu 15.10 64bit installation and get every time after entering the (correct) password the error message:  cryptsetup: unknown fstype, bad password or options?  But after few seconds (without any further interaction) this error message is replaced by the expected message:  cryptsetup: sda5_crypt set up successfully  That's it and the system is started.  Any suggestions what could be the problem? Is it merely cosmetic or serious?


Preparing myself for qualifying exam, I found this problem in residues in some previous qualifying exam, and I am stuck and don't know how to solve it, any helps? $$f(z)=(ze^{2-z}+(2-z)e^z)e^{(z-1)^{2}+(z-1)^{-2}}  $$ at z = 1

I tried my best to solve this problem from what I learned in residues, but the solution seems very far from what I was doing!! Is there any way other than using Laurent series expansion?  Here is the problem: $$f(z)=(ze^{2-z}+(2-z)e^z)e^{(z-1)^{2}+(z-1)^{-2}}  $$ at z = 1  Thank you


I am writing a simple add-on to move the 3D Cursor. It works with a modal operator, the 3D locations follows the mouse position, but it gets the input from the keyboard if the user wants to type a specific dimension. I created a draw handler to show the keyboard input during the modal. It's working, if I press the keyboard number it stores the numbers as it should, but it doesn't show anything until I move the mouse. I would like it to show the numbers as I pressed them on the keyboard. Is there any way I can achieve that?

I am trying to code a custom modal operator which captures key inputs. But the event queue seems to be so fast that when I hit a key it is reported multiple times. For example when I type the word "hello" it might end up in something like "hheelllloo". The modal method looks like the following  def modal(self, context, event):     if event.type in string.ascii_uppercase:         return self.add_char(context, event.type.lower())      else:         return {'PASS_THROUGH'}   What could I do to fix the problem?


Sometimes we mistakenly think something is true and so we tell it to others; Unbeknownst to us, the thing is not true. How to call such untruthfulness?     Example:      A: You told me she will not be in this party. You lied to me.       B: No, I didn't know that myself. She told me she is out of town.   In the above scenario, what B had said to A was a "honest lie".   has been used for such untruthfulness. But I need other words/terms/phrases for that. And I need a verb, something meaning "honest lying".  There is also this word "confabulate" [same source] which is more of technical usages and means mistakenly and with no intention taking something false as true. But this is obviously not what I want.

Imagine a scenario where Jim provides a piece of information to Sue. Jim believes this information to be true and correct, but is later proven to be mistaken. Some might say that Jim lied to Sue. I believe this to be the wrong word, because the misinformation was unintentional.  Is there a better word for this type of unintentional "lie"?


I like to believe one can't be 100% sure of anything, for one can't be 100% sure their brain functions correctly (because if it doesn't, it may mistake itself as functioning correctly as a result). Is there a name for and/or existing material on this theory?

I have been thinking about objectivism vs relativism recently.  It is easy to prove by contradiction that there exist objective truths. However, is it possible to know anything?  If you assume a human makes errors in logical deduction 5% of the time, then it seems to follow that it is impossible for a human to know anything (eg how to know 1+1=2). In which case it seems that the answer to my question is unknown. This is confusing to me, any thoughts?


I have exactly the same problem as explained in , however the question is very old and the provided answers doesn't work so I decided to ask the question again:  Sound from audio,video and in generalany of sound is choppy. I can hear some part but then immediatly it mutes.  outout of sudo lshw -c multimedia    *-multimedia                    description: Audio device        product: System Controller Hub (SCH Poulsbo) HD Audio Controller        vendor: Intel Corporation        physical id: 1b        bus info: pci@0000:00:1b.0        version: 07        width: 64 bits        clock: 33MHz        capabilities: pm pciexpress bus_master cap_list        configuration: driver=snd_hda_intel latency=0        resources: irq:22 memory:b0050000-b0053fff   *-usb        description: Video        product: WebCam        vendor: Sonix Technology Co., Ltd.        physical id: 4        bus info: usb@1:4        version: 1.00        capabilities: usb-2.00        configuration: driver=uvcvideo maxpower=98mA speed=480Mbit/s   I use Lubuntu 16 on acer aspire one.

I have a little Sony VAIO P series computer on which is installed Ubuntu 15.10 running LXDE. I've found that all audio played on the device is choppy, everything from MP4 videos played on VLC, to Skype, to Festival, is choppy. Here is a sound recording to illustrate:    From aplay -l, I can see that the hardware playback device is HDA Intel MID ALC275. What could be going wrong and how could I try to fix it?


I have tried solving the equation but I keep getting zero. I also can't find a proof online, I think because it is a rather specific question.

How to show this function's discontinuity?  $ f(n) = \left\{     \begin{array}{l l}      \frac{xy}{x^2+y^2} & \quad , \quad(x,y)\neq(0,0)\\      0 & \quad , \quad(x,y)=(0,0)    \end{array} \right.$


For example I have '-Werror=return-type' because I'll get weird bugs if I accidentally forget to return a value in my function. I don't know why it isn't an error in C++. I also have missing-variable-declarations to avoid bugs. However I don't want unused-variable/label as errors on debug builds because I'll have a few of them before I finish writing the code. (That error is on in release build). Recently I added macro-redefined which inspired this question because there's a lot more I should add. Which warning as errors do you guys recommend in debug builds?

What compiler warning level do you recommend for different C/C++ compilers?  gcc and g++ will let you get away with a lot on the default level.  I find the best warning level for me is '-Wall'.  And I always try to remove fix the code for the warnings it generates.  (Even the silly ones about using parenthesis for logical precedence rules or to say I really mean 'if (x = y)')  What are your favorite levels for the different compilers, such as Sun CC, aCC (HPUX ?), Visual Studio, intel?  Edit:  I just wanted to point out that I don't use "-Werror" (but I do understand it's utility) on gcc/g++ because, I use:   #warning "this is a note to myself"   in a few places in my code.  Do all the compilers understand the #warning macro?


I have a varying number of lists of varying length. I need to try to create all possibilities of having one item per list. How can this be done in Python? Example l1 =  ['a', 'b', 'c'] l2 =  [1, 2] l3 =  [6]  # Expected result: [   ['a', 1, 6],   ['a', 2, 6],   ['b', 1, 6],   ['b', 2, 6],   ['c', 1, 6],   ['c', 2, 6], ]  I could have 3 loops in this case, but since this is for an ambiguous number of lists it doesn't scale. I tried playing with itertools a bit but couldn't figure out what to use for my case and couldn't find similar questions here. So any help would be appreciated.

How can I get the Cartesian product (every possible combination of values) from a group of lists?  Input:   somelists = [    [1, 2, 3],    ['a', 'b'],    [4, 5] ]   Desired output:  [(1, 'a', 4), (1, 'a', 5), (1, 'b', 4), (1, 'b', 5), (2, 'a', 4), (2, 'a', 5) ...]


I came across the below scenario twice today.  Image 1    Image 2

While reviewing suggested edits and first posts by new users today, the review system did something new - an alert appeared that suggested that what I was reviewing was probably spam, and prompted me to take a careful look at it.  Should I be doing anything differently than I otherwise do while reviewing when I see this? Additionally, are my actions contributing to helping the spam prevention systems learn?


I am new to this site, but I know there is a similar question on it, it's just not quite the same. What I mean by "all things X" could, for example, be like this:  "He was interested in all things baseball." meaning that s/he is interested in everything that has something to do with baseball. In this example there is a noun after "All things..." Now, would it be proper for an adjective to replace the X? I.e. s/he did all things possible but still couldn't find the solution. Thank you in advance

I've seen the expression in some company names; for example , .  Is the expression "All things X" a parody of some other popular phrase, or does it have its own meaning? Or is it just a misuse of grammar?


I am trying to write a document where I have multipled instances of -->, <--, ----> etc... as it's a formatted answer to a referee response (and it follows their styling). However, LaTeX seems to convert all instances of -> into inverted question marks, and all instances of <- into upside down exclamation points.  Is there a way to block this from happening? Preferably some sort of command at the beginning of the document that would apply throughout and reroute whatever escape character this is triggering, or otherwise some way to escape this?

When typing < or > in LaTeX and compiling with pdflatex, the less than and greater than symbols appear at upside down exclamation points. I'm not in math mode.


One of the paladin spells is , which summons a spirit taking the form of a steed. Can it carry my party's stuff, like a regular animal can?

From page 240 of the Player's Handbook, find steed says, in part:     You summon a spirit that assumes the form of an unusually intelligent,   strong and loyal steed, creating a long lasting bond with it.   Appearing in an unoccupied space within range, the steed takes on the   form that you choose, such as warhorse, a pony, a camel, an elk, or a   mastiff....      When the steed drops to 0 hit points, it disappears, leaving behind no   physical form. You can dismiss your steed at any time as an action,   causing it to disappear. In either case, casting this spell again   summons the same steed, restored to its hit point maximum....   It seems convenient for it to show up with the regular attire of a mount, and to have that stick with it. However, this basically gives it the functionality of the "leomund's secret chest" (p254) which is a level 4 spell with a 5,050gp cost.  What's to stop a player from loading the summoned warhorse with luggage and dismissing it until they feel like accessing it again?  I am not looking for "it's up to the DM" type answers. Rules as intended are best, rules as written will substitute, and info from official WotC sources is great too.


I have a bounty that is about to expire from its 24 hour grace period. None of the answers actually work.  has proved useful, in that I have learnt something useful from it, but  looks promising if the answerer follows up to address my comment. I am tempted to award the bounty to the first of these answers and then raise a second bounty on the same question but it is not clear to me from the  whether they can be awarded a second time on the same question.

It's possible to offer and award bounties of reputation on questions.   What is a bounty? How can I find questions that have a bounty attached? How do I start a bounty? When can I start a bounty? Why is the system requiring me to choose a bounty amount that's higher than the minimum? Can I use Markdown formatting in the bounty remarks? Can I edit the remark? How long is the bounty period? How do I award a bounty? Can I award a bounty to my own answer? Can I award a bounty to an old answer? If I offer a bounty on someone else's question, can I award the bounty to their answer? After awarding the bounty, can I remove it or move it to another answer at a later time? What happens if there's no answer after the bounty period? What happens if I feel my question is still unanswered? What is automatic awarding? Are bounty awards exempt from the 200 points/day reputation limit? How does Community Wiki mode affect bounties? How does user deletion or post dissociation affect bounties? Can I award a bounty to an answer from a deleted user or one where the author was dissociated? Can I offer a second bounty after the first one has expired? Can I raise my bounty? What happens if a bounty question is closed or deleted? Why can't I vote to close or migrate a bounty question? What happens if I delete my account while I have an active bounty? Do I keep an awarded bounty when I delete my answer? What happens if a question where I awarded a bounty later gets deleted or migrated? Can I cancel my bounty? Can I affect / divide / share part of my bounty to two (or more) users? How many outstanding bounties can a single user have?      See also:  in the Help Center


:  Why and how are some questions deleted?  Analysing user biorhythm.. Merging with Russian botnet..   :  How do I ask a good question? I have two XmlDocuments and I would like to move an XmlNode selected from one of the documents and append it at a particular location in the other document. The naively intuitive approach of simply calling AppendNode(xmlNodeFromDocument1) at the appropriate place of document 2, of course doesn't work because the method does not take care of manipulating the owning document. I finally found the answer literally as I was writing up this question, but since it took so long for us to find it in the System.Xml classes, I figured I'd post it here to assist anyone else stuck searching for it.  Is it a bug? Joke? Break-in?

I posted it on  as well, but in any case: there's a network-wide bug affected all sites' Help Centers. E.g. this link:  shows long-deleted Stack Overflow content :  What topics can I ask about here? a "reticulated spline" is a valid geometrical entity. They're used a lot in terrain modelling. Because you can get non-reticulated splines, someone wiseguy obviously thought it good to start reticulating them.


After adding the most recent set of updates, I can't get into Ubuntu at all. I get a screen saying that I am running in low-graphics mode, 'your screen, graphics card and input device settings could not be detected correctly etc'.   I can hit return and then get to the next screen saying 'what would you like to do?' however, i can't choose from the 4 options, the only keystroke that will register is escape, which takes me to a black screen with a login.   I have an Nvidia GeForce 7050/nForce 610i and it has caused problems in the past, but I have always got round it by choosing to boot in recovery mode. Now, no matter which version I try to boot into I can't get into Ubuntu at all.

Note: This is an attempt to create a canonical question that covers all instances of "low-graphics mode" error that occurs to a user, including but not limited to installation of wrong drivers, incorrect or invalid lightdm greeters, low disk space, incorrect installation of graphics card like ATI and Nvidia, incorrect configuration of xorg.conf file while setting up multiple monitors among others. If you are experiencing the "low-graphics mode" error when trying to login but none of the following answers work for you, please do ask a new question and then update the answers of this canonical question as and when your new question gets answered.   When I try to boot into my computer, I am getting this error:  The system is running in low-graphics mode Your screen, graphics cards, and input device settings could not be detected correctly. You will need to configure these yourself.   How do I fix the failsafe X mode and login into my computer?  Answer index:


It always give the second conditional regardless of the input. Is (userName == "Charles") the correct way of doing this conditional? or do i need something else.  import java.util.Scanner; public class Name_input {        public static void main(String[] args) {            Scanner input = new Scanner(System.in);              String userName = input.next();             System.out.println(userName);              if (userName == "Charles")             {                 System.out.println("Correct Name");             }                    else if (userName != "Charles")             {                 System.out.println("Incorrect Name");             }              }  }

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


I am using R software to fit different type of models such as gaussian process model, linear mixed effect model, ANN and etc on many independent variables to estimate my dependent parameter. I have question: is it necessary to normalize my input data such as temperature (use any normality test) before fitting linear mixed effect models or other type of models? In fact, if my input parameters don't be normal, should I use normal function to convert them into the normal shape and then fit the models?? Thanks

In regression, standardization is recommended in ordered to assess the relative importance of predictors. However there seems to be an assumption of normality? How would the interpretation work for predictors following different non normal distributions? It seems confusing...


Sometimes things are slow (no not here; I mean on smaller sites) and I go hunting for questions to answer.  I usually search by tag, but this of course turns up questions I've already answered -- which I often don't remember until I click through from the search results.  How do I search specifically for questions I have not answered?  I tried the advanced-search help but didn't find my answer there.

Recently I asked if it were possible to find questions with just one answer and as a result we got an .  That's great, but ...     Is there a way to restrict the search to questions where that one answer isn't mine? That would help. :-)   It's certainly possible to search for , but it's not possible to exclude your own posts as far as I can tell:   -user:me searches for posts that . user:1-67 doesn't search for posts from user #1 to user #67, but searches for .  (And I'm not sure that will help anyway since I don't think it would be possible to simultaneously exclude 69-max(userID).) -Ericson searches for posts that , but since my last name is in the the metadata and not the searchable portion of posts: no joy.   And of course none of this will actually work to eliminate the questions that that I've answered already and want to ignore.  In general, If I'm involved in a Q&A (or ) the notification procedures do a good job of keeping me up-to-date with developments.  But when I search, it's often to find questions I've not noticed before.  So being able to eliminate questions I have already answered would be a generally useful feature for me.


Let say I got a string with the name of the variable I want to create.  If I want to create it with a global scope, I'd use window["myString"] = 100; or global["myString"] = 100; on Nodejs.  Is there a way to do the same but create the variable with local scope? (Ex: Inside a function)  EDIT: Note: The goal is to access the variable with its name directly. Ex: myString  I already know that I could easily create a object that would have the value as an attribute. Ex: obj.myString. But this is not what I'm looking for.

If you want to use global functions and variable dynamically you can use:  window[functionName](window[varName]);   Is it possible to do the same thing for variables in the local scope?  This code works correctly but currently uses eval and I'm trying to think of how else to do it.  var test = function(){     //this = window     var a, b, c; //private variables      var prop = function(name, def){         //this = window         eval(name+ ' = ' + (def.toSource() || undefined) + ';');              return function(value){             //this = test object             if ( !value) {                 return eval('(' + name + ')');             }             eval(name + ' = value;')             return this;         };      };      return {         a:prop('a', 1),         b:prop('b', 2),         c:prop('c', 3),         d:function(){             //to show that they are accessible via to methods             return [a,b,c];         }     }; }();  >>>test Object >>>test.prop undefined >>>test.a function() >>>test.a() 1 //returns the default >>>test.a(123) Object //returns the object >>>test.a() 123 //returns the changed private variable >>>test.d() [123,2,3]


I intuitively understand that the limit goes to 1 and I can solve with L'Hôpital but I can't without it. I tried to call it equal to y and rise both sides to the base e but doesn't seems to work. $\underset{n\to \infty }{\text{lim}}\frac{\ln (n+1)}{\ln (n)}$

Find the limit of $\frac{\log(n+1)}{\log(n)}$ where $n\rightarrow\infty$. Here $n$ is a natural number so I guess we can't use L'Hopital


I'm trying to save the map canvas as an image in Python in QGIS. I've looked in a few places but haven't been able to get something to work. I need a function where I can specify the extent of the map and the image size. Very similar to the "snapshot" command line function that can be used with QGIS. But the problem with the snapshot function is that it has to start QGIS each time and then close it.

I wrote a script to create a big number of heat maps for a given scenario. I would like to save the result of every heat map as an PNG image. I have figured it out doing it with simple Map Rendering but the quality of the result is too low. Furthermore I would like to export to OpenLayers using the same code, which does not seem to be possible with simple rendering.   Now I am trying to do it with QgsComposition instead. Manually in the Map Composer you can just set the paper color to transparent and disable the background of the map canvas.   This is the code that I have so far. I just cannot figure out why it is not working. The result png-file always has a white opaque background.   My OS is Windows 7 and I'm using QGIS 2.6 Brighton.  I hope someone can help me out here.  # PARAMETERS mainPath = 'path/to/folder/' filename = 'filename' imageType = "png" imageWidth_mm = 400 imageHeight_mm = 160 dpi = 300  mapRenderer = iface.mapCanvas().mapRenderer()  c = QgsComposition(mapRenderer) c.setPlotStyle(QgsComposition.Print)  c.setPaperSize(400, 160)  x, y = 0, 0 w, h = c.paperWidth(), c.paperHeight() composerMap = QgsComposerMap(c, x ,y, w, h) c.addItem(composerMap)  # get all items and disable the backgrounds itemList = c.items() c.removeItem(itemList[2]) c.removeItem(itemList[2]) itemList[2].setBackgroundEnabled(False) itemList[3].setBackgroundEnabled(False) # add them to the composition c.addItem(itemList[2]) c.addItem(itemList[3])  c.refreshItems() c.refreshDataDefinedProperty(QgsComposerObject.AllProperties)  c.setPrintResolution(dpi) dpmm = dpi / 25.4 width = int(dpmm * c.paperWidth()) height = int(dpmm * c.paperHeight())  # create output image and initialize it # image = QImage(QSize(width, height), QImage.Format_ARGB32) image = QImage(QSize(width, height), QImage.Format_ARGB32_Premultiplied) image.setDotsPerMeterX(dpmm * 1000) image.setDotsPerMeterY(dpmm * 1000) #image.fill(0)  imagePainter = QPainter(image)  # This part does not seem to have any effect #brush = QBrush(Qt.BrushStyle(0)) # transparent brush # #imagePainter.setBackgroundMode(0) #c.setBackgroundBrush(brush)  c.renderPage( imagePainter, 0 ) imagePainter.end()   imageFilename =  mainPath + filename + '.' + imageType image.save(imageFilename, imageType) print 'image saved' print 'done'