Mathematica

surprising comparison of Mathematica 5.2 and 7.0
Dear Mathematica friends, the following program runs 4.7 times faster and uses 22.7 times less memory in Mathematica 5.2 than in Mathematica 7.0. Fortunately, it gives the same result. ClearAll["Global`*"]; c[1] = 2; Table[ a = Sum[c[i] r^i,{i,1,n}] + O[r]^(n+1); s = 4(1-1/(1+1/3+r-a*Cos[2t]))//Normal//T... 25 Jul 2010 02:17

Need to align data from sublists to Union of dates from all sublists
Hi everyone, A simple example of my problem follows. I have a nested list, myList, with the following dimensions: Dimensions[#] & /@ myList {{93, 2}, {93, 2}, {93, 2}, {88, 2}, {92, 2}, {93, 2}, {93, 2}} The columns of each sublist contain values and SQLDateTime(s) respectively, i.e: m... 22 Jul 2010 05:56

Cases vs. StringCases vs. Select and StringMatchQ vs. StringFreeQ
Hello, I am currently working on manipulating data in "vCard"-like format, and have become confused by the actions of the Cases, StringCases and Select functions. Consider the small list: In[1]:= list = {"DTEND:19260412T175900", "DTEND:20070207T050000", "END:VCALENDAR", "MM"} ; In[2]:= Cases[list, ___~~"END:... 23 Jul 2010 08:04

Code highlighting
I write Mathematica programs. Reading of a code with many nests or a deep code is a difficult problem. I want to suggest a feasible solution. When I move the cursor through the code then the nearest part of the code will be highlighted. There is the nearest part of the code in the nearest level. Something like t... 22 Jul 2010 05:56

Graphics3D stereo
I have this code and data and to visualize the 3D graph effectively, I want to view it in side-by-side stereo. The two calls to Graphics3D work, but I can't seem to find two viewpoints that give a vivid stereo effect. (I have successfully viewed many stereo pics in the past in print media.) Does anyone have ... 22 Jul 2010 05:56

Mathematica Special Interest Group (Washington DC Area)
Mathematica SIG (http://web.me.com/hrbishop.pmsi) MEETING 23 July 2010, 7:30 am Science Applications International Corporation (SAIC) 8301 Greensboro Drive McLean VA Southern Corner of Westpark Drive and Greensboro Drive Agenda 1. Prepared Talks "Counter Missile Design" by Mel Friedman AB... 22 Jul 2010 05:56

Very very basic question about Mathematica
You are not dealing with strings. You are using symbols and expressions and none of the expressions happen to involve strings. Manipulate is a scoping construct. Since you want s to depend on the control, bring the definition of s within the Manipulate's scope. Manipulate[ s = x + h; Plot[s, {x, 0, h}, Plo... 24 Jul 2010 05:52

Displaying a list of variables together with their names
Hello MathGroup, I am looking for a simple and (code-wise) efficient way to display a list of variables (simple symbols) together with their values in a table. My Mathematica skills got a little rusty, I was wondering what is a simpler / better way to achieve it than this: SetAttributes[dynamicVariableDisp... 23 Jul 2010 08:04

Strange 26base enumeration
I need an algorithm to get such a table: A B .. .. Z AA AB .. .. AZ BA BB .. .. BZ CA .. .. ZA ZB .. .. ZZ AAA AAB .. .. AAZ ABA .. .. ABZ .. AZA .. AZZ BAA .. ZZZ AAAA AAAB .. .. ZZZZ AAAAA AAAAB .. Any idea? Bruno ... 23 Jul 2010 08:04

Writing to same file from several kernels?
Hi all, assume I have several kernels running which should all log their progress to the same file. Is this possible? Opening a stream from each of kernels does not work, neither does passing on the stream object. Any ideas? TIA Sebastian ... 29 Jul 2010 07:28