Mathematica

Misprint
Hello, It seems that there is a misprint on the page http://www.wolfram.com/products/mathematica/usersanduses/mersenne.html We read that "In June 1999 an international group of mathematicians, computer scientists, and hobbyists <...> discovered that 2^6972593-1 is prime." But it is not true: In[3]:= PrimeQ[2^2... 20 Jul 2010 04:50

Fitting complicate functions
I have a very complicate function which has to be inserted into a loop that calculates it zillions of times. This slows the simulation speed and I'm wondering if it is possible to fit the function with a simpler one by adjusting its fitting parameters. I used "Fit" of Mathematica and was partially succesful: however, I... 20 Jul 2010 04:50

Continued Fraction Trouble
I ran across an unexpected behavior of FromContinuedFraction that I hope someone can help me with. I originally thought is was a representation problem, but now I am not sure. When I was playing with the continued fraction solutions of a quadratic x^2 -a c x -c = 0, The continued fraction solution x = a... 24 Jul 2010 05:52

parallel computing - obsolete functions?
Hi all, I'm starting to look into parallel computing with Mathematica. Unfortunately the documentation is not very helpful and, put mildly, confusing. It seems that a lot of information has been lost in the transition from v.6 to v.7 where some functionality has been moved from the Parallel Computing Toolkit to co... 17 Jul 2010 08:43

Percentage Formating
There's an easy way of formating percentage numbers form reporting purposes... I mean... 0.05263 --> 5.26% Thanks ! ... 20 Jul 2010 08:03

Avoid the use of certain functions
Hi, Is there a way to ask Mathematica to avoid expressing answers in terms of certain functions. For example, I can stand Sec, Csc, Sech, and Csch and would rather see Sec^-1, etc. Thanks! ... 20 Jul 2010 04:50

Show left hand side
Hi, When Mathematica prints an expression not terminated by a semicolon, I find it hard to match up the output with what I was trying output when a block of commands has many commands not terminated by a semicolon. Is there a way to get Mathematica to output the LHS so when I have R=1+1 it outputs R = 2 or s... 23 Jul 2010 08:04

Combine matrices of equal height
Hi, Given two matrices of equal height, what's the best way to combine them. Here's what I did TF[m_] := Flatten[Transpose[m]] Combine[m1_, m2_] := Partition[Join[m1 // TF, m2 // TF], Length[m1]] // T Surely there's a better way of doing it. Thanks! ... 18 Jul 2010 02:00

How to parametrize a block of commands?
Hi, Suppose I have written the following block of commands for computing the differential geometry elements on a surface of evolution given by r=F[g] z=Z[g]. This topic not my interest, I just cooked it up for an example. TF[m_] := Flatten[Transpose[m]] Combine[m1_, m2_] := Partition[Join[m1 // TF, m2 // ... 18 Jul 2010 01:59

total newbie
I downloaded mathematica tonight so I can do an assignment. I have to modify a file our teacher posted on the class website, solve some equations and generate a curve... okay, this file ends in the extension nb. I need to know how to make the commands in the file execute. Now don't laugh. I put the curs... 20 Jul 2010 03:45