Comfirmation of Existence of finite field
Explicit construction of a finite field with $p^n$ elements
I'm working from the URL I found here:    My ssh client is Ubuntu 64 bit 11.10 desktop and my server is Centos 6.2 64 bit. I have followed the directions. I still get a password prompt on ssh.  I'm not sure what to do next. How do I merge two dictionaries in a single expression (taking union of dictionaries)? If the matrix $A^3 = 0$, is $A$ singular? I'm currently developing a script for Blender to handle Mesh Frequency Decomposition.  The script is nearly complete, but i need one more thing: The SciPy library to compute eigenvalues and eigenvectors.  Following the installation instructions on , I'm able to install it as well as Numpy. Numpy works fine, but I can't even import SciPy:  Traceback (most recent call last): File "/CAF_FD.py", line 4, in &lt;module&gt; ImportError: No module named 'scipy' Error: Python script fail, look in the console for now...   By the way, I'm working on Linux 64 bit and I've installed SciPy and Numpy with my package manager.  Edit: When I try to use SciPy with a terminal prompt, it works. How is the recommended next badge determined exactly? According to , the     "Progress to next badge" bar automatically selects the badge you're closest to earning (or that's most logical to go for next)   While "the badge you're closest to earning" is pretty easy to determine: it's the bar with the most progress, I'm wondering what "most logical to go for next" means. Because right now on Meta Stack Exchange, I can track two badges: Illuminator and Legendary. My progress for Illuminator is 66.40% and for Legendary it's 66.67%, yet Illuminator is shown as the recommended next badge:    On some child metas where I barely have any activity, Student is shown as recommended next badge with a progress of 0/1, but I do have cast some votes so I have a small progress towards e.g. Civic Duty. So obviously there is some other logic at work, but what? Traffic (views, visits) is not correctly registered on Site Analytics or Area 51 In the ,  can monitor some things like the total traffic on the site. However, it seems to be broken at the moment, all figures are almost zero. This is how it looks for Meta Stack Exchange (other sites show similar pictures): I need an approach to allow delegated admins (i.e., non-Administators) to add members to Public Groups and Collaboration Groups (the GroupMember and CollaborationGroupMember objects).  I added a custom object (UserGroupRequest__c) to capture which Users should be added/removed to which Groups.    I've also built a batchable class to process the requests.  However, GroupMember is a Setup object, and CollaborationGroupMember is not.  So this doesn't work if I combine the operations in a single batchable class.  Should I instead be using 2 batch classes, calling one from the finish method of the other?    Any recommendations on how best to proceed?  Am I way off base?    Would a trigger on the Request object perhaps be better? I'm guessing that there may be a permission problem if this is attempted via a trigger as the delegated admins won't be able to add users to public Groups.  Also, I'm guessing the trigger approach would run into the same mixed DML issue - on Insert of the Custom object, I would need to Insert/Delete from GroupMember and from CollaborationGroupMember, and then perform a 2nd update on the Custom object to indicate that processing was completed... What is the name of the operation $v^T H v$? To find out how something is called is the one thing I don't know how to use Google for.  If I have a vector $v$ and a symmetric matrix $H$, then the operation $v^T H v$ gives me some sort of projection of the matrix $H$ on the vector $v$. For example if $H$ is the Hessian, the operation gives me the second derivative in the direction of $v$.  What is the name of this operation? Module 'pdftexcmds' not found after update Yesterday I updated my distribution (tlmgr update --all) and now I cannot use TikZ with lualatex anymore.  Minimal working example:  \documentclass{article} \usepackage{tikz} \begin{document} a \end{document}   Compilation output:  &gt; lualatex a This is LuaTeX, Version 1.10.0 (TeX Live 2019)                                                                                                                                                                         restricted system commands enabled.                                                                                                                                                                                  (./a.tex                                                                                                                                                                                                              LaTeX2e &lt;2019-10-01&gt; patch level 3                                                                                                                                                                                     luaotfload | main : initialization completed in 0.098 seconds                                                                                                                                                         (/opt/texlive/2019/texmf-dist/tex/latex/base/article.cls                                                                                                                                                              Document Class: article 2019/10/25 v1.4k Standard LaTeX document class                                                                                                                                                (/opt/texlive/2019/texmf-dist/tex/latex/base/size10.clo))                                                                                                                                                             (/opt/texlive/2019/texmf-dist/tex/latex/pgf/frontendlayer/tikz.sty                                                                                                                                                    (/opt/texlive/2019/texmf-dist/tex/latex/pgf/basiclayer/pgf.sty                                                                                                                                                        (/opt/texlive/2019/texmf-dist/tex/latex/pgf/utilities/pgfrcs.sty              ...  (/opt/texlive/2019/texmf-dist/tex/generic/pgf/frontendlayer/tikz/tikz.code.tex (/opt/texlive/2019/texmf-dist/tex/generic/pgf/libraries/pgflibraryplothandlers. code.tex) (/opt/texlive/2019/texmf-dist/tex/generic/pgf/modules/pgfmodulematrix.code.tex)  (/opt/texlive/2019/texmf-dist/tex/generic/pgf/frontendlayer/tikz/libraries/tikz librarytopaths.code.tex))) No file a.aux. ABD: EveryShipout initializing macros (/opt/texlive/2019/texmf-dist/tex/context/base/mkii/supp-pdf.mkii [Loading MPS to PDF converter (version 2006.09.02).] ) (/opt/texlive/2019/texmf-dist/tex/latex/epstopdf-pkg/epstopdf-base.sty[\direc tlua]:1: module 'pdftexcmds' not found:         no field package.preload['pdftexcmds']         [kpse lua searcher] file not found: 'pdftexcmds'         [kpse C searcher] file not found: 'pdftexcmds' stack traceback:         [C]: in function 'require'         [\directlua]:1: in main chunk. l.165       \directlua{require("pdftexcmds")}  ?    It seems that a Lua package is missing.  Is this a bug? Am I missing a package? How to submit webform programmaticaly? I have seen somewhere that classical distances (like Euclidean distance) become weakly discriminant when we have multidimensional and sparse data. Why? Do you have an example of two sparse data vectors where the Euclidean distance does not perform well? In this case which similarity should we use? Does moving variable declaration outside of a loop actually increase performance? I am using ArcGIS 10.1 and I have a non-spatial table and some layers in a Data Frame.   When I switch to Layout View I want to be able to show the map in a data frame element and the table in another element (something that one could do with "Add Table To Layout" from Table Options, but I want to do this in one step without having to go to Table Options).   Is there a way to do this using ArcPy?   I couldn't find any function in the ArcPy library that would create a new Layout Element ... and then I also don't know how to add the contents of the table to the Layout Element. What is a plain English explanation of "Big O" notation? I'd prefer as little formal definition as possible and simple mathematics. If you are talking on behalf of you and someone else what is the correct usage?  On behalf of my wife and me On behalf of my wife and I On behalf of me and my wife On behalf of myself and my wife On behalf of my wife and myself ...  My understanding is that after that phrase you would carry on talking in first person. My book says:     For most of the small objects, both are same. But for mammoth ones, they are really different ones. And in a gravity-less environment, COG is absent; COM still exists.   Ok, what's the big deal when things are small and big? How these two :  &amp; ? Traverse a list in reverse order in Python So I can start from len(collection) and end in collection[0].  I also want to be able to access the loop index. Double-column listing package Not too well up on LaTeX, but I want to use the listings package for listings spanning a two-column format.  Unfortunately, asterisks cannot save me (like for figures/tables); this doesn't work:  \begin{lstlisting*} ... \end{lstlisting*}   I've Googled about, but got no satisfactory answer, and getting a bit desperate. Should be simple... hope I'm not missing something stupid. Perhaps it's possible to embed this into a separate spanning float?  Help?  (P.S., I've posted this on the main stackoverflow site as well...  if this is considered a duplicate, please comment and I'll remove the other. Getting a bit desperate fighting a deadline.) I already have a 6 month valid UK business visa received prior to April 24 2015. I was supposed to travel to the UK in April, but my trip was cancelled on medical grounds.  I am now planning to visit the UK in July for tourism. Would it be fine for me to do so? Will I be allowed to enter the UK? Should I carry the original invite letter and medical certificate to prove why I didn't go the first time? I'm trying to write a program in C (on Linux) that loops until the user presses a key, but shouldn't require a keypress to continue each loop.  Is there a simple way to do this? I figure I could possibly do it with select() but that seems like a lot of work.  Alternatively, is there a way to catch a ctrl-c keypress to do cleanup before the program closes instead of non-blocking io?