I've just did an update.   $ sudo tlmgr update --self tlmgr: package repository http://sunsite.informatik.rwth-aachen.de/ftp/pub/mirror/ctan/systems/texlive/tlnet tlmgr: saving backups to /usr/local/texlive/2013/tlpkg/backups tlmgr: no updates for tlmgr present. tlmgr: no updates available $ sudo tlmgr update --all [...] [108/109, 06:49/06:49] update: collection-pictures [1k] (32769 -&gt; 33307) ... done [109/109, 06:51/06:51] update: collection-publishers [1k] (32864 -&gt; 33330) ... done tlmgr: package log updated: /usr/local/texlive/2013/texmf-var/web2c/tlmgr.log running mktexlsr ...  mktexlsr failed (status -1), output:  running mtxrun --generate ...  mtxrun --generate failed (status -1), output:  Can't exec "kpsewhich": No such file or directory at ./tlmgr line 679. Use of uninitialized value $TEXMFSYSVAR in scalar chomp at ./tlmgr line 679. Can't exec "kpsewhich": No such file or directory at ./tlmgr line 680. Use of uninitialized value $TEXMFSYSCONFIG in scalar chomp at ./tlmgr line 680. Can't exec "kpsewhich": No such file or directory at ./tlmgr line 681. Use of uninitialized value $TEXMFLOCAL in scalar chomp at ./tlmgr line 681. Can't exec "kpsewhich": No such file or directory at ./tlmgr line 682. Use of uninitialized value $TEXMFDIST in scalar chomp at ./tlmgr line 682. Use of uninitialized value $TEXMFDIST in concatenation (.) or string at ./tlmgr line 693. Can't exec "kpsewhich": No such file or directory at /usr/local/texlive/2013/tlpkg/TeXLive/TLUtils.pm line 2785. Use of uninitialized value $tmfsysconf in scalar chomp at /usr/local/texlive/2013/tlpkg/TeXLive/TLUtils.pm line 2785. Use of uninitialized value $tmfsysconf in concatenation (.) or string at /usr/local/texlive/2013/tlpkg/TeXLive/TLUtils.pm line 2786. Cannot open /web2c/updmap.cfg for writing: No such file or directory at /usr/local/texlive/2013/tlpkg/TeXLive/TLUtils.pm line 2928.   Then I run mtxrun --generate which seemed to work.  Then I've tried to compile  and got:  (/usr/local/texlive/2013/texmf-dist/tex/generic/pgfplots/pgfplots.revision.tex) (/usr/local/texlive/2013/texmf-dist/tex/latex/pgf/frontendlayer/tikz.sty (/usr/local/texlive/2013/texmf-dist/tex/latex/pgf/basiclayer/pgf.sty (/usr/local/texlive/2013/texmf-dist/tex/latex/pgf/utilities/pgfrcs.sty (/usr/local/texlive/2013/texmf-dist/tex/generic/pgf/utilities/pgfutil-common.te x ! I can't find file `pgfutil-common-lists.tex'. l.556 \input pgfutil-common-lists.tex  (Press Enter to retry, or Control-D to exit) Please type another input file name:   When I enter /usr/local/texlive/2013/texmf-dist/tex/generic/pgf/utilities/pgfutil-common-lists.tex it seems to work until it gets to pgfmathfunctions.integerarithmetics.code.tex which it also doesn't find.  As  with the same problem had problems with the path, I checked it (added breaks to make it easier to read):  $ echo $PATH /usr/local/texlive/2013/bin/x86_64-linux: /usr/local/texlive/2013/bin/x86_64-linux: /usr/local/texlive/2013/bin/x86_64-linux: /usr/local/texlive/2013/bin/x86_64-linux: /usr/local/texlive/2013/bin/x86_64-linux: /usr/local/sbin:/usr/local/bin: /usr/sbin:/usr/bin:/sbin:/bin:/usr/games: /usr/local/games   I don't know why TexLive is there 5 times, but that should not be a problem (?)  Before the update, I had pgfplot 1.09.  Can anybody please tell me how to fix this problem?
I am using texlive 2013, and just ran the following command to update the packages.  sudo ./tlmgr update  -all   After it finished, I tried to compile tex documents that uses tikz package as the following MWE shows:   \documentclass{article}  \usepackage{tikz}  \begin{document}       aaaa  \end{document}   Then pdflatex complains; it said:   (/usr/local/texlive/2013/texmf-dist/tex/latex/pgf/utilities/pgfrcs.sty  (/usr/local/texlive/2013/texmf-dist/tex/generic/pgf/utilities/pgfutil-common.tex  ! I can't find file `pgfutil-common-lists.tex'.  l.556 \input pgfutil-common-lists.tex   The problem is that, pgfutil-common-lists.tex is indeed in the directory:   /usr/local/texlive/2013/texmf-dist/tex/generic/pgf/utilities/   Why is that? pdflatex should be able to find it, right? I even download the  again, and replace the pgf directory in   /usr/local/texlive/2013/texmf-dist/tex/generic/   Nothing changed at all........... Any idea? Thank you for your critics.  %=====================================================================  Then followed the comments, I type the following command in the terminal:    sudo mktexlsr gives me command not found;  mktexlsr gives me:  mktexlsr: /usr/local/texlive/2013/../texmf-local: directory not writable.     Skipping...  mktexlsr: /usr/local/texlive/2013/texmf-config: directory not writable. Skipping...  mktexlsr: /usr/local/texlive/2013/texmf-dist: directory not writable. Skipping...  mktexlsr: /usr/local/texlive/2013/texmf-var: directory not writable. Skipping... mktexlsr: Done; Forkpsewhich pgfutil-common-lists.tex, nothing pops up.
Using oscilloscope safely with AC mains I know there is quite few discussions already on this topic, but since English isn't my first language, I though it better to get some more information about this.  I have used oscilloscopes to troubleshoot electronics problems and measure AC engine current spikes at startup, but I have no experience using them to measure high voltage levels and my experience is with old analog scopes.  So now I have this new DSO and the input rating is 400V peak to peak AC, so it can handle about 140V AC RMS? Not that I'm going to input that much there.  Since I live in Europe the mains here are 230 V @ 50 Hz I can't measure them directly.  If I set the attenuation from the scope and probe to 10X, the voltage is 23 RMS and it is safe to measure? And yes the probes are rated for 1kV.  If that is true, it's also safe to measure voltage between two main lines (400V RMS), since the peak-to-peak would be about 112 volts?  SAFETY: When I am measuring AC, I will be using the scope from its internal battery or with a isolating transformer (1:1) so that it is floating, meaning that there is no connection to earth ground. Are there any other safety issues I have not realized? Is it ok to answer based someone's older answer on SE? Possible Duplicate:             This question will probably be closed in a few minutes. It is a duplicate but I couldn't find the question using with meta search.  Anyway, , . In this case, is vote to close the new question as a possible dublicate not the best choice? Looks to me a little bit not ethical. Is it possible to use a MacBook Pro as a second monitor for my iMac? Both of them have a Thunderbolt port.  If not, is there any other way? Keyboard language keeps changing in Windows 10 So I recently did a clean install of Windows 10 English. I configured it to have English UI language but Norwegian keyboard. I have several problems with that setup:   The keyboard language keeps switching to English constantly I can't see the language bar nor the language toggle popup when I swap:     I have bound the Norwegian keyboard layout to Shift+Alt+0 and that works, but it's annoying to have to do that every 5 minutes. Also I find it weird that I can't see the language bar neither on the desktop nor on the toolbar.  Anyone have any idea of what might be wrong?  Here are some screenshots of my settings:          P.S. The only time I see the language toggle popup is actually when I'm logged out in the lock screen and press Win+Space. Nothing happens if I do that after being logged in. Is "I'm being angry" ungrammatical? I am using Ubuntu 12.10.  Please outline the different ways I can upgrade to 13.04. Rigorous proof that surjectivity implies injectivity for finite sets If I close (is delete an option ?) my Gmail account, will somebody be able to register using my email address and read my mails?  I want to close my Gmail account but I don't want anybody to impersonate me with my old address.  Same question with Yahoo! Mail. Do they allow addresses to be re-used? Why are newer generations of processors faster at the same clock speed? Why, for example, would a 2.66 GHz dual-core Core i5 be faster than a 2.66 GHz Core 2 Duo, which is also dual-core?  Is this because of newer instructions that can process information in fewer clock cycles? What other architectural changes are involved?     This question comes up often and the answers are usually the same. This post is meant to provide a definitive, canonical answer for this question. Feel free to edit the answers to add additional details. If $x+{1\over x} = r $ then what is $x^3+{1\over x^3}$? If $$x+{1\over x} = r $$ then what is $$x^3+{1\over x^3}$$  Options: $(a) 3,$ $(b) 3r,$ $(c)r,$ $(d) 0$ Cannot see my wifi [10ec:d723] when trying Ubuntu I have a bunch of views/reports built for my client. The reviewers then click download csv for the excel file. They asked if the views could download themselves daily to a folder.  Is that possible? And could you share links or knowledge how to handle this. I have been trying to figure it out.  Note: Right now the user is downloading CSV's from Drupal 7, an install of Moodle 1.9 in a Drupal 6 Shell and Survey Monkey. After they download and combine using Excel, the user creates reports that way for the users we have come to our events. Being a Front-end developer, coding is not my strength. Windows 10 100% Disk Usage after Startup After startup for 5 minutes my system is very slow. The Task Manager shows that the disk usage is at 100%. (Later this number is around 2-4 %, but sometimes for 1-2 minutes go up again at 100%.)  I searched a lot on Google. For example I read , and also other pages. I opened two topic on Microsoft answer.  and one in Hungarian.  But I didn't found the solution yet. So I would like to ask Community's help. :)  Here the steps I already done:   I disabled everything at startups (including services) and the issue is the same.  I disabled Prefetch and Superfetch, the Baground Intellingent Transmission, Windows Search and Windows Defender but the issue is still persists. I made a health check on HDD, I made defrag and file system error check, but there are no errors. Also I tried to reinstall the HDD's driver. I made a full hardware check up, with no errors. The Windows and all the drivers are up-to-date. I tried a clean start. The issue is the same. I deleted Dropbox and all antivirus. I turned of the MSI mode.      I using also Linux, where this error is not occurs. Good to know, that Windows had 4 partitions, but I deleted 2 of them for the Linux. I don't know what partitions was these but both was only 10 - 20 MB.  I using a Dell Inspiron 15R SE 7520 with Windows 10 Home.  Personally I think it can be the Intel Rapid Store Technology "driver", because the problem started around when I installed it. (However I'm not sure.) And my hardware not supported yet by Intel, so I have no the newest driver. However I deleted Intel's software and driver and the issue is the same.    Thank you in advance for your assistance! When does the amount of skew or prevalence of outliers make the median preferable to the mean? I know that "deviations in the data are devil", and when the distribution is highly skewed, it is better to consider median as average rather than mean, but how to decide these hard-limits.  For example:   CASE 1:   Assume X = 10,20,30,40,50,60,70 In this case, I think that it is better to use mean and that it will give very accurate results.  CASE 2:   Assume X = 10,20,30,40,50,60,70,7000 In this case, I think that it is better to use median instead of using the mean.  CASE 3:    Assume X = 10,20,30,400,500,600,700 In this case, I think it is better to use IQR (Inter Quartile Range)    But I'm stuck with how to decide these hard-limits i.e. which to use in which condition, in general.   I've found a tool working on subjected principle, which takes context-less sample-distribution as input and determines whether mean is close/moderate or against the null-hypothesis.  Find References:-     (For Mean Test)  (For Median Test)   What I'm really looking is a good answer which states how to derive these conclusions. A question here on meta for instance may stick around for quite a while. A feature-request  maybe even for months. Then the status (tags) gets changed to  or  or whatever and the OP does not get notified.  On a normal post-edit we get a notification but retagging does not count for that. Please add retagging to the edit notifications. How to tell what length of chain to get? Search in favorited questions? I wonder if it is possible to search in just my favorited questions?  If not, can it be considered as a feature request? What are the biggest changes between UA Ranger and PHB Ranger? I am already a little bit familiar with Linux distros like Debian or Ubuntu (yeah, very similar) but I wanted to try Red Hat based - CentOS 6.2. I have installed it on my Windows 7 host in VirtualBox and tried to play with it a little. I have come across a small problem, namely: the default eth0 interface is down by default. I use the option with NAT (the virtual machine is 'behind' the host). Even if I bring the interface up with ifconfig eth0 up, it does not work right away. I get this after bringing the interface up: eth0      Link encap:Ethernet  HWaddr 08:00:27:0F:00:8A           inet6 addr: fe80::a00:27ff:fe0f:8a/64 Scope:Link           UP BROADCAST RUNNNING MULTICAST MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:6 errors:0 dropped:0 overruns:0 carriers:0           collisions:0 txqueuelen:1000           RX bytes:0 (0.0 b)  TX bytes:468 (468.0 b)           Interrupt:19 Base address:0xd020  lo        Link encap:Local Loopback           inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)  virbr0    Link encap:Ethernet  HWaddr 52:54:00:75:C2:9B           inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0 [root@centos ~]# _  What should be done more to configure the network on CentOS machine? Noetherian property for exact sequence Let $0 \to M' \xrightarrow{\alpha} M \xrightarrow{\beta} M'' \to 0$ be an exact sequence of $A$-modules. Then $M$ is Noetherian is equivalent to $M'$ and $M''$ are Noetherian.  For the ''$\Leftarrow$'' case:  I guess if we let $(L_n)_{n\geq 1}$ be an ascending chain of submodules of $M$, then $(\alpha ^{-1}(L_n))_{n\geq 1}$ is a chain in $M'$, and $(\beta(L_n))_{n\geq 1}$ is a chain in  $M''$. For large $n$ both these chains are stationary. Then why we know the chain $(L_n)$ is stationary?   Thanks!