Mathematica

FindFit constrains when parameters are in table
The form would be ba = Array[b, 5]; cons = Join[ Thread[Abs[ba] < 1], Thread[Rest[ba] <= Most[ba]]] {Abs[b[1]] < 1, Abs[b[2]] < 1, Abs[b[3]] < 1, Abs[b[4]] < 1, Abs[b[5]] < 1, b[2] <= b[1], b[3] <= b[2], b[4] <= b[3], b[5] <= b[4]} params = Join[{a}, ba] {a, b[1], b[2], b[3], b[4], b[5]} ... 20 Dec 2009 07:04

CellChangeTimes?
CellChangeTimes seems to be a new field that's been added, or at least shows up, when you apply Show Expression to a cell. For me at least, and the way I use Mathematica, it doesn't seem to be anything I'll ever want to use or know about, and after a while it adds an immense amount of distracting clutter to th... 22 Dec 2009 04:53

Is it possible to dynamically construct arguments to
Hi Leo, Somehow I missed your original post. First, let me suggest a possible refinement of Daniel's solution which will be protected against possible global values that dummy variables may have: In[1]:= a0 = 1; b0 = 2; Hold[With[{a = a0, b = b0}, a b]] /. {a0 -> 2, b0 -> 3} // ReleaseHold Out[1] = 2 ... 19 Dec 2009 07:17

FindFit
Can anybody help me? I want to try to show my model (function) and my data in the same graph so I can see that my conclusions are correct. data= { {40,0.0624}, {50,42.2.276}, {58,127.718}, {60,216.608}, {70,2040.088}, I used FindFit for Exponential as my model to plot: t200= {Exp200} t200= {Exp300} model=aE... 20 Dec 2009 07:04

vector and matrix valued functions
Hello, I am working with functions that have vector and matrix valued arguments. I'd like to postpone going to a component representation as late as possible, but that is not easy because some vectors are already in the component form and this gives me error messages from cross and times. One example: I have ... 21 Dec 2009 08:00

Special Characters Palette
I notice that the Special Characters Palette is diferent from other Palettes.....it contains 'folders' for Letters and Symbols....this has a lot of advantages.... 1. How do you make such a Palette? 2. Is it possible to add 'folders' to the Special Characters Palette?....I would like to put 'Basic Typsett... 18 Dec 2009 07:12

ErrorListPlot
Dear All, How can I draw ErrorListPlot on logarithmic graph? In other words, how to make function likeErrorListLogPlot or ErrorListLogLogPlot ? --- Tatsuo ... 17 Dec 2009 08:10

Braids: simple question
How do I get from a BraidWord to an image? e.g., (sigma1)^-1 (sigma2 ) (sigma1)^-1 (sigma2 ) P_ter ... 17 Dec 2009 08:10

Export[..., ImageResolution, ... ImageSize]
Anyone have insight on this problem with image resolution in version 7? SetDirectory(a)NotebookDirectory[]; plot = Plot[x, {x, 0, 10}]; Export["plot.gif",plot,ImageSize->5*72,ImageResolution->300] The export command seems to ignore ImageResolution. Here is what used to work in V5.2 of M... 17 Dec 2009 08:10

MathematicaMark7 compare with AMD 3.2 GHz
i run SystemInformation[] and then Benchmark on my PC. The results were: System: Linux x86 (32-bit) Date: December 16, 2009 Mathematica Version: 7.0.1 Benchmark Result: 0.63 Comparing to the other PC in the Reportlist my system seems to be very slow. My PC is a AMD 3.2 GHz XP 64 CPU with 2 GB RAM. Anyth... 21 Dec 2009 08:00