Mathematica

Problem overwriting init.m file
On March 1, 2006, Arnoud Buzing made a posting about creating kernels. I tried it out as I was having a problem creating a remote kernel (the post follows below) and lost the contents of my init.m file - much to my surprise and disappointment. Why would this code cause the init.m file to be replaced (really what wa... 10 Aug 2010 04:45

Custom dialog during evaluation
I would like to have a custom dialog appear while an evaluation is in progress (maybe even add that familiar spinning flower). I know it is easy for an experienced user to see when Mathematica is working, but this would help novice users who use some of my notebooks. Does anyone have suggestions on how to do thi... 13 Aug 2010 07:02

Equation solving question
I'd like to solve the system of equations below and Mathematica gets stuck, are the tricks I can do to help it solve this kind of system? It should produce solution q1=p1, q2=p2, q3=p3, q4=p4 lagr = p1 (Log[q1/(q1 + q3)] + Log[q1/(q1 + q2)]) + p2 (Log[q2/(q1 + q2)] + Log[q2/(q2 + q4)]) + p3 (Log[q3/(q1 + q... 11 Aug 2010 04:55

Compile with Boolean Arrays
Can anyone explain why this works: MatrixMultiply = Compile[ {{a, _Integer, 2}, {x, _Integer, 1}}, Inner[Times, a, x, Plus], {{Inner[__], _Integer, 1}} ] MatrixMultiply[{{2, 0}, {0, 1}}, {2, 1}] But this doesn't: LogicalMatrixMultiply = Compile[ {{a, True | False, 2}, {x, True | False, 1}... 10 Aug 2010 04:45

Frontend suggestions
Since the subject of possible enhancements to the FE is being discussed, I wonder if we could determine which feature would be most popular. I have two requests: 1) Infinite undo! 2) Better documentation of functions such as Import that perform a range of operations. So many details seem to slip between t... 13 Aug 2010 07:02

FindMinimum inside another FindMinimum
Hello MathGroup, I'm trying to minimize a function (F[b,J]-1)^2, where the argument b will itself be determined by another minimization: F[b_,J_] := b^2 - b*J + J^2 B[J_] := Last[ FindArgMin[ F[b,J] , {b,1.} ] ] When I try the outer minimization, I run into trouble: FindMinimum[ b = B[J]; (F[b, J] - 1... 10 Aug 2010 04:45

ploting piecewise function in contourplot3d section
hi, i want plot x - .5*(y + z) = (250*10^6) when y < .5*(x + z) .5*(y + x) - z = (250*10^6) when y >= .5*(x + z) how can i do that in contourplot3d ... 10 Aug 2010 04:45

remote kernel problem
hello, i am having problems launching remote kernels. i have a Xeon server (Linux) on which mathematica is installed, and the "math" command works. on my laptop, i have linux too, and on mathematica i add the kernel to be launched on the remote (the server) node. then i try one example: 2+2 i press shift... 10 Aug 2010 04:45

problem with calling Mathematica from a Web application in ASP .NET
My Web application calls Mathematica via MathLink. It worked fine until I have recompiled it with Visual Studio 2010. Now every time it needs to use MathLink, a dialog box "Choose MathLink program to run" appears. How can I get rid of this problem? ... 8 Aug 2010 07:59

ExistsURLQ
Hello everybody: I=B4m trying to find the best way to test if any internet link is available or not, something similar to FileExistsQ, but with a web URL. As I could not find anything about this topic on the documentation, I =B4ve been rewieving some internal packages and the idea I had is this one: << Uti... 11 Aug 2010 04:55