Is it possible that the interaction effect is significant while the individual effect(s) is not?
The main effect will be non-significant if the interaction is significant?
I need to build a function which parses the domain from a URL.  So, with   http://google.com/dhasjkdas/sadsdds/sdda/sdads.html   or  http://www.google.com/dhasjkdas/sadsdds/sdda/sdads.html  it should return google.com  with   http://google.co.uk/dhasjkdas/sadsdds/sdda/sdads.html  it should return google.co.uk. What is the difference between encrypting something and hashing something?  in what situations would I want one or the other? How can I `alias sudo !!`? Does the universe have a center? Find the number of ways in distributing $8$ distinct balls into $6$ distinct boxes such that there is at least $1$ ball in each box.  We are well acquainted with the traditional Inclusion-Exclusion principle in solving this and it will come up as $191520$ ways.  I tried in this way:  When we distribute $8$ balls into $6$ boxes we have two possible cases  Case $1.$ There are exactly $2$ boxes with $2$ balls each  Case $2.$ There is exactly $1$ Box with $3$ balls in it.  For Case $1$, the distribution is done by choosing $2$ boxes from $6$ boxes and $2$ balls from $8$ balls and those two balls can be arranged in $2!$ ways. But I require another two balls from remaining $6$ balls to be placed in each of these two boxes which can be done in $\binom{6}{2} \times 2!$ ways. Finally remaining $4$ balls can be distributed in remaining $4$ boxes in $4!$ ways. So total number of ways for Case $1.$ is  $$\binom{6}{2} \times \binom{8}{2} \times 2! \times \binom{6}{2} \times 2! \times 4!=604800$$  For Case $2$, the number of ways is  $$\binom{6}{1} \times \binom{8}{3} \times 5!=40320$$  I am pretty sure the value obtained for Case $2.$ is correct. but I could not find where I went wrong in Case $1.$ Why is there a mismatch between size reported by LVM and the size reported by df -h? I'm new to LVM and have been very confused by this:  I am transfering a large file to a partition that I thought had about 1.5 terabytes of space on it.  Near the end of the transfer, rsync exits with an error claiming that the partition is full.  I investigate and find the following:  $ sudo lvm lvs   LV        VG     Attr   LSize   Origin Snap%  Move Log Copy%  Convert   home      system -wi-ao  97.66G                                         log       system -wi-ao  48.81G                                         log.audit system -wi-ao   9.75G                                         root      system -wi-ao 341.59G                                         swap      system -wi-ao   4.88G                                         temp      system -wi-ao  97.66G                                         var       system -wi-ao   1.46T     This seems to imply that /var (the partition that I'm transfering to, has the amount of storage I expect.  However, then I see:  $ sudo df -h Filesystem            Size  Used Avail Use% Mounted on /dev/mapper/system-root                       331G  1.3G  313G   1% / /dev/mapper/system-temp                        95G  188M   90G   1% /tmp /dev/mapper/system-var                        95G   90G     0 100% /var /dev/mapper/system-home                        95G  188M   90G   1% /home /dev/mapper/system-log                        48G  264M   45G   1% /var/log /dev/mapper/system-log.audit                       9.5G  340M  8.7G   4% /var/log/audit /dev/sda1              99M   25M   70M  26% /boot tmpfs                 8.0G     0  8.0G   0% /dev/shm   I'm guessing this has something to do with the volume being resized at some point.  While I have reliable backups, I'd rather not interrupt services for the time it will take to get the backup and restore.  Thus, is there anyway to make the filesystem seen by the OS match the space available according to lvm without losing data? Make grub keep its default boot under kernel updates I dual-boot my machine and I want it to default to boot into windows so that whenever I restart the machine remotely from my home it will be able to get back into Windows (instead of Ubuntu).  The problem is that every time Ubuntu upgrades the kernel, I have to reset the default boot item of grub back to windows. This is because the grub menu loader uses positions i.e. 6 for default OS to boot. And when Ubuntu installs a new kernel it changes that order.  I am looking for a way to configure grub to remember its default boot item under kernel updates. show that if $n\geq1$, $(1+{1\over n})^n<(1+{1\over n+1})^{n+1}$ How would I find a minimum weight spanning tree for W? I have many tags marked as "interesting" and others as "ignored". (I use Java at work, I'm a Cocoa guy by night, any anything dealing with Windows/.NET/C# simply doesn't apply to me.) When tags are added to the list in the right navbar, they appear in the order in which they were added. There are several problems with this:   It can be difficult to visually locate a tag quickly, unless you have memorized its location. The tags appear as the same gray boxes like everywhere on SO, but with a small "x" afterward, and they wrap based on size. This tends to leave a ragged right margin and wasted space. Ordering based on when the tag was added is not always the most intuitive default. Various users might prefer to view them alphabetically, by popularity, recent activity, etc.   It would be nice to introduce a tabbed interface to switch between various orderings, and remember the value in the cookie, profile, etc. Coupled with this, perhaps users could specify a custom ordering that works best for them? (Currently the workaround is to copy all the tag names, remove them all, and re-add them in the desired order, but this is obviously annoying.)  Thoughts? Are security.ubuntu.com updates eventually merged into normal updates? Upon my observation, seems new packages will first appear in security.ubuntu.com, but if you upgrade later, they will appear in XX.archive.ubuntu.com (depends on your config),  Was that true ? How to change sign text color in Minecraft? I have gone through every single website and video to try to make a sign with colored text, but nothing works. Can anyone help me to get a sign to say:  Place Block(dark blue and bold text)  I really want this for a map I am making and I need help. How to install Chrome browser properly via command line? I am trying to install chrome browser via command line.  I tried this:  $ apt-cache search chrome browser   The results show that the proper term is "chrome-browser," so I tried that:  $ sudo apt-get install chrome-browser   And then "Y" for the Y/n question.  But the installation threw errors.  Does someone see anything wrong with the commands I issued? I am trying to host some static content in an Amazon S3 bucket and to have that content available through my own domain.  The bucket in question is called "e.tl-dr.org" and I have "index.html" set as the index document. I can visit  and I see the contents of index.html (just "test"). This works fine.  I also have added the CNAME entry for "e.tl-dr.org" pointing to "s3.amazonaws.com" from within my registrar's site. (I am not using the AWS Route 53 DNS services, which is what most tutorials about this seemed to be geared at.) So now "" correctly shows the file, but just the bare domain only gives me S3's standard 403 message.  Is there anything else I need to set up to get this working? inputenc Error: Unicode char \u8: not set up for use with LaTeX This is with ref to my previous question .  \documentclass[11pt,table,a4paper]{article} \usepackage{lmodern} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc}  \usepackage{CJKutf8} \usepackage[english,russian]{babel}  \newenvironment{SChinese}{%  \CJKfamily{gbsn}%  \CJKtilde  \CJKnospace}{}   \begin{document}  \selectlanguage{russian}   Это мой первый многоязычный докладе.   Инфантильный гипертрофический стеноз привратника - это серьёзное   \selectlanguage{english}   This is my first multilingual report.   \begin{CJK}{UTF8}{}   \begin{SChinese}     这是我的第一个多语种的报告。   \end{SChinese}   \end{CJK}    \end{document}   when I try to compile it, I get following error message.  LaTeX Warning: Unused global option(s):     [table].  (./data.aux (/usr/local/texlive/2011/texmf-dist/tex/latex/cyrillic/t2acmr.fd)) (/usr/local/texlive/2011/texmf-dist/tex/latex/lm/t1lmr.fd)  LaTeX Font Warning: Font shape `T2A/lmr/m/n' undefined (Font)          using `T2A/cmr/m/n' instead on input line 15.   ! Package inputenc Error: Unicode char \u8:  not set up for use with LaTeX.  See the inputenc package documentation for explanation. Type  H &lt;return&gt;  for immediate help.  ...                                      l.18 ...�ный гипертрофический стеноз привра...   How can I avoid such error message. How do I create a file of size 10M, format it with ext3 filesystem and then mount it in /media/fuse?  I tried with  mkfs -t ext3 file   then to mount it  mount -t ext3 file /media/fuse   It didn't work because it said that file wasn't a block device. Can anybody help me? How to merge columns in a table? I have this table, but wanted to format the first row. I like to match the two columns of first row, and last two columns of the same first row. Any suggestion on how to do that?  \begin{table}[!h]  \caption{Comparison of percentages.} \begin{tabular}{lclclclclc} \hline \hline  Mode &amp;  Var  &amp;  Cum\\ \hline {}       &amp; EF   &amp; CHF    &amp; EF2   &amp; CHF2\\ 1   &amp;  17.5 &amp; 19.1   &amp; 17.5  &amp; 19.1\\ 2   &amp;  11.8 &amp; 12.7   &amp; 29.3  &amp;  31.9\\ 3   &amp;  6.6  &amp;  5.6         &amp; 35.9    &amp;  37.4\\ \hline \end{tabular} \end{table} Given a simple graph and its complement, prove that either of them is always connected. I was tasked to prove that when given 2 graphs $G$ and $\bar{G}$ (complement), at least one of them is a always a connected graph.  Well, I always post my attempt at solution, but here I'm totally stuck. I tried to do raw algebraic manipulations with # of components, circuit ranks, etc, but to no avail. So I really hope someone could give me a hint on how to approach this problem. Replace \input{fileX} by the content of fileX automatically Suppose I have a document with multiple include or input statements  \input{fileA} \input{fileB}   etc.   Is there an easy way to generate a single .tex file where \input{fileA} is replaced by the actual content of fileA etc. without copying it manually? Novel about interstellar war: Both sides win, both sides think they lost