Pass by reference not working in java?
Is Java "pass-by-reference" or "pass-by-value"?
Can I travel to the UK unaccompanied on an accompanied child visa now that I am over 18? How to get instance variables in Python? Why I think tension should be twice the force in a tug of war Applying for a UK Tourist Visa from outside country of origin Extending my Root Paritition I've Win8/Ubuntu Dual boot. I already have 4 partition so i cannot create a new partition and mount it elsewhere. So, this () question did not help.  Here's a screen shot of my Gparted (run on Ubuntu Live)   How can I extend /dev/sda6  so that  i can make use of unallocated space ?  (w/o failing my current grub) Say, we have a query like this:  select a.*,b.* from  a join b on a.col1=b.col1 and len(a.col1)=10   Assuming the above query uses a Hash Join and has a residual, the probe key will be col1 and the residual will be len(a.col1)=10.  But while going through another example, I could see both the probe and the residual to be the same column. Below is an elaboration on what I am trying to say:  Query:  select * from T1 join T2 on T1.a = T2.a    Execution plan, with probe and residual highlighted:         Test data:    create table T1 (a int, b int, x char(200)) create table T2 (a int, b int, x char(200))  set nocount on declare @i int set @i = 0 while @i &lt; 1000   begin       insert T1 values (@i * 2, @i * 5, @i)     set @i = @i + 1   end  declare @i int set @i = 0 while @i &lt; 10000   begin     insert T2 values (@i * 3, @i * 7, @i)     set @i = @i + 1   end   Question:    How can a probe and a residual be the same column? Why can't SQL Server use the probe column only? Why does it have to use the same column as a residual to filter rows again?  References for test data: food safety regarding re freezing twice cooked chicken I am defrosting a cooked chicken to use in a curry it will be thoroughly heated at a high temperature. If I have too much curry will i be able to freeze it, as the cooked chicken was frozen before? Where can I ask a question about finding general software that meets certain requirements? I have a list of requirements for a program, but I don't know what program meets these criteria. That's about general-purpose software, for example, not a programming IDE or statistical workbench, questions about which would certainly go to respective sites.  Is this question appropriate on Stack Overflow? Where should I ask about it? On Super User or elsewhere? Inner join using an array column Having trouble indexing and executing a query in O (log n) time.  The query includes an INNER JOIN, an ORDER BY, and an equality operation. If I understand the laws of databases correctly, a query can be indexed and executed in O (log n) time (or thereabouts) if a non-equality operator is not used on more than one column. In this case, I believe the INNER JOIN does count as an equality operator and the non-equality operator would be the ORDER BY portion of the query. This table has upwards of 10,000,000 rows and needs to handle several reads and writes per second.  Using PostgreSQL. This is what the table looks like. As you can see, the column 'Names' is a list property and it is the column that the INNER JOIN goes against:  Age Names                       Date 34  ['carla', 'john', 'sam']    3/13/2011 26  ['json', 'cindy', 'joel']   3/13/2011 72  ['beth', 'amber', 'susie']  3/13/2011 14  ['john', 'jim', 'debie']    3/13/2011   This is the query that we are trying to do:  SELECT * FROM the_table WHERE Age==26 AND Names=='john' ORDER BY Date   My background is from using App Engine's Big Table, so I've used equality operators here to indicate that 'john' should be one of the names in the Names column. This would be an acceptable query in GAE's big table, it would execute in O (log N) time as all Big Table queries are reqyured to do. I am assuming there is a way to do this in PostgreSQL as well since PostgreSQL accepts list data types as columns.  Is this possible to do in PostgreSQL?  If so, how should the index be set up (we can't figure out how to set up an index that takes into account the three properties)? Let $S$ be a finite collection of real numbers (not necessarily distinct). If any element of $S$ is removed then the remaining real numbers can be divided into two collections with same size and same sum ; then is it true that all elements of $S$ are equal ?  (I know the result is true if the &quot;reals&quot; are replaced by &quot;integers&quot;.) Should I use exit() or just return statements in main()? Personally I favor the return statements because I feel it's like reading any other function and the flow control when I'm reading the code is smooth (in my opinion). And even if I want to refactor the main() function, having return seems like a better choice than exit().  Does exit() do anything special that return doesn't? My question relates to Chapter 3, Exercise 8 in &quot;Baby Rudin&quot;. It states: If $\sum_n a_n$ converges, and if $\{b_n\}$ is monotonic and bounded, prove that $\sum_n a_n b_n$ converges. My attempt would have been: Since $\{b_n\}$ is monotonic and bounded, $\{b_n\}$ converges and it exists $\inf \{b_n\}$ as well as $\sup \{b_n\}$. But then we have $$ \left| \sum_n a_n \inf \{b_n\} \right| \leq \left| \sum_n a_n b_n \right| \leq  \left| \sum_n a_n \sup \{b_n\} \right| \leq \max \left( \left| \sup \{b_n\} \right|, \left| \inf \{b_n \} \right| \right)\varepsilon \leq \tilde{\varepsilon} $$ since $\sum_n a_n$ converges and $\max \left( \left| \sup \{b_n\} \right|, \left| \inf \{b_n \} \right| \right)$ is a finite number. This would imply, by the comparison test, that $\sum_n a_n b_n$ converges as well. $\quad \Box$ But as there was a way longer, more rigorous proof chosen in this , I'm a bit suspicious that my proof is not complete. Am I missing something?  EDIT: Thanks everyone! @hermes: The last part of your proof gave me the following idea. As $\lim_{n \to \infty} b_n = c$ and $\{b_n\}$ is monotonic, couldn't we just set $b_n = c - c_n$ with a monotonically decreasing sequence $\{c_n\}$ which has $\lim_{n \to \infty} c_n = 0$. Then we have $$\sum_n a_n b_n = \underbrace{c \sum_n a_n}_{\text{converges by assumption}} - \underbrace{\sum_n a_n c_n}_{\text{converges by Theorem 3.42}} \leq \varepsilon_1 - \varepsilon_2 = \varepsilon $$ since  Theorem 3.42 Suppose  the partial sums of $\sum_n a_n$ form a bounded space $\quad \checkmark$ $c_0 \geq c_1 \geq c_2 \geq \dots \quad \checkmark$ $\lim_{n \to \infty} c_n = 0 \quad \checkmark$  Then $\sum_n a_n c_n$ converges.  Thus $\sum_n a_n b_n$ converges as well. $\quad \Box$ Now that should hold, I think. So I wouldn't need to go through all the estimates. I'm trying to make a command that creates a book that has many items with enchantments at level 1,000. However, I don't know why it keeps saying:     Data tag parsing failed: Unbalanced quotation:   {ench:[{id:0,lvl:1000}],Unbreakable:1,display:{Name:"Prot   It's supposed to say "Protection Armor", but it only shows "Prot" for some reason. This is the same with all of my other items. Here is the one part of the command that I've showed you:  {ench:[{id:0,lvl:1000}],Unbreakable:1,display:{Name:"Protection Armor"}} How can I set my Ubuntu 12.04 LTS to boot to console without GUI? So I installed Ubuntu server to run some tests on a VM. For various reasons I couldn't get a specific DEB file, and instead of using a shared folder I decided it would be a good idea to install ubuntu-desktop so I can run Firefox and grab the file directly from the web.   Now, every time I boot my machine I get the graphical interface, but I have no reason for it since I'm running tests with the LAMP server.  I tried this    And this    If anyone has any idea for a solution, I'd appreciate it.   BTW: I thought about simply uninstalling ubuntu-desktop, but I feel like I might need it in the future, so, I really just want to disable the GUI.  EDIT:  While this solution is not perfect I realized, it works for now:  On the  question, user Michael K mentions that:  " Okay another way would be to disable the lightdm service in init:  /etc/init/lightdm.conf   in there there is a section like this:  start on (filesystem and started dbus and (drm-device-added card0 PRIMARY_DEVICE_FOR_DISPLAY=1 or stopped udev-fallback-graphics))   "  While this worked perfectly, I can't access the GUI with the startx command - the system just crashes. And I guess I'll need to uncomment the section to load startx.  Considering the fact that I want to keep the server running for as long as possible, having to restart it every time I want to log in the GUI is kinda unproductive.  EDIT2:  I guess it's possible simply to kill the GUI (  ) when I log in the system, it's still counter productive, but it works too.   EDIT3:   Michael K's reply worked fine. I just realized that to call the GUI I need to run lightdm and not startx Clearly if $\lambda$ is an eigenvalue of $A$ then $p(\lambda)$ is an eigenvalue of $p(A)$ where $p$ is a polynomial. And there are cases where $A$ may have eigenvalues other than these.   Is there a general rule for finding all eigenvalues of $p(A)$? Does it depend on the field from which the elements of $A$ are taken? Are their any partial solutions to this problem? I want a translucent PNG overlayed on top of my screen (above all windows). I'm using this to mark a visible region while streaming.   So far I've figured out that qiv -transparent filename.png will add a mask to the window, but it's a boolean mask. I don't get translucent fading with the alpha channel.  I know several effects have opacity, and I can sent window opacity, so I'm hoping there's some way to display an image that way.  What program, tool, or widget can I use to blend an image onto the top of the desktop? SEO for importing the page header with JavaScript rather than PHP My website has the same header/sidebar/footer on every page, so I have been importing them using PHP. To do this I forced all html files to be processed through the apache servers PHP handler via htaccess. I have come to understand that is not necessarily the best thing to do and so found out how to do everything I need using simple JavaScript. I also store a variable in the initial page that then gets used in the imported html.  Questions: By switching from:  &lt;?php include "_header.html";?&gt;   to  &lt;script type="text/javascript" src="_header.js"&gt;&lt;/script&gt;   I am noticing that the "view source" shows the header.js link, whereas the PHP method will show the source as if the html had been there all along. Will search engines recognize the html in the JavaScript just as they would when loaded with PHP?  I understand it is bad practice to alter the page contents -after- it is downloaded, but this doesn't fall into that category does it? That would detail things like after a wait function, or after user interaction, correct?  Are there any other foreseeable downfalls to switching to JavaScript and turning off the forced PHP processing? "He acted strange(ly?)" I read the answers in this question, but they still leave my question open:   I didn't find a way in the Google Webmaster Tools to invoke a re-download of my robots.txt.  Through some error, my robots.txt was replaced with:  User-agent: * Disallow: /   And now all my content was removed from Google search results.  Obviously, I'm interested in correcting this as soon as possible. I already replaced the robots.txt, but I can't find a way to make Google update the cached version. Editing Gsettings unsuccesful when initiated from cron