wolfram-mathematica

In Mathematica, how do you change the order of importance of variables? for example: if i enter b+c+a+d, i get a+b+c+d but i want b and d to preceed other variables. so that i get b+d+a+c note, i'd like to use it where + is non-commutative First you need to define an ordering function like: In[1]:= CPOrdering[a]=3; CPOrdering[b]=1; CPOrdering[d]=2; CPOrdering[c]=4; Although, for more complicated examples, you should probably be smarter about it than this - ie use pattern matching. Then you can sort expressions using In[5]:= CirclePlus[a,b,c,d] SortBy[%,CPOrdering] Out[5]= a\[CirclePlus]b\

Is it possible to use Install[] to start a MathLink program with a custom PATH environment variable? I am trying to use mEngine to connect Mathematica to MATLAB on Windows. It only works if mEngine.exe is launched when the PATH environment variable includes the path to the MATLAB libraries. Is it possible to modify the PATH for launching this program only , without needing to modify the system path? Or is there another way to launch mEngine.exe ? @acl's solution to wrap mEngine.exe in a batch file, and temporarily modify the PATH from there, works correctly: I used this as the contents of

Has anybody figured out a way to modify Graph objects in Mathematica 8? In particular, how to get the same functionality you get when you right click on the graph. Some of the new graph functions conflict with Combinatorica , is there a way to force Mathematica to use a built-in version of the function? In other words, is there a way to get access to built-in CompleteGraph after I do Needs["Combinatorica"] which imports Combinatorica version of CompleteGraph ? To clarify 1, Context Menu on Graph lets you change GraphStyle and GraphLayout, and I'd like to be able to change them programmatically

Mathematica comes with a simple java program that allows to inspect the communication between front end and the kernel. It's called LinkSnooper and in general it works quite nice. It looks like this I think I can improve the behavior and usability of the program to some extend, but to do this, I need to reimplement some parts. One fundamental piece that I need is a text pane, which has the following properties: it can receive a lot of data and it probably should use a fast ring-buffer so that the very first log-lines are removed when the data grows too much. Another possibility is that it

I have already checked all the examples and settings in the Mathematica documentation center, but couldn't find any example on how to choose the numbers that will be shown on the axes. How do I change plot axis numbering like 2,4,6,.. to PI,2PI,3PI,...? You can find an example here : Ticks -> {{Pi, 2 Pi, 3 Pi}, {-1, 0, 1}} Howard has already given the correct answer in the case where you want the labels Pi , 2 Pi etc to be at the values Pi , 2 Pi etc. Sometimes you might want to use substitute tick labels at particular values, without rescaling data. One of the other examples in the

This example routine generates two Throw::nocatch warning messages in the kernel window. Can they be handled somehow? The example consists of this code in a file "test.m" created in C:\Temp: Needs["JLink`"]; $FrontEndLaunchCommand = "Mathematica.exe"; UseFrontEnd[NotebookWrite[CreateDocument[], "Testing"]]; Then these commands pasted and run at the Windows Command Prompt: PATH = C:\Program Files\Wolfram Research\Mathematica\8.0\;%PATH% start MathKernel -noprompt -initfile "C:\Temp\test.m" Addendum The reason for using UseFrontEnd as opposed to UsingFrontEnd is that an interactive front end may