Mathematica

Creating sub-list based on a given criterion
Hello I was wondering if there is any straightforward way to bin a list into sub-lists containing those elements that full-fill a given criterion. Consider the following list ds= {{{0,0,1},{1,0,-1},{2,0,-1},{3,0,-1},{4,0,-1},{5,588,-1},{6,2345,1},{7,2418,1},{8,2323,1},{9,2179,1}},{{480,23,1},{487,23,1},{470,29,1... 1 Jul 2010 08:50

Matrix multiplication (again !)
Sorry about the question but there are 195 post on the topic (now 196 ...). So ... is it possible in Mtahematica to have something similar to Product[T[r[[i]],r[[i-1]],x[[i]]-x[[i-1]],w],{i,2,8}]; where T[aL, a0, L, w] is a matrix function of the four variables, that can have the same behaviour as the Dot function... 26 Jun 2010 09:43

coordinates on a single line of output corresponding to each
Am Fri, 25 Jun 2010 11:52:51 +0000 (UTC) schrieb Narasimham <mathma18(a)hotmail.com>: How to obtain data= Table[{u,v,u+v, u-v, u*v/10 },{u,0,4.5,.5}, {v,0,3.5,.5}] for 80 points on 80 separate lines ? TIA Narasimham Grid[Prepend[ Flatten[0.5 Table[{u, v, u + v, u - v, u*v/10}, {u, 0, 9},... 26 Jun 2010 03:18

Sum of terms --> list
Hi, I have an expression that is a sum of terms, like a+b+c and I want to convert it to a list, with as many elements as the number of terms in the sum of terms, and with each element being each of the terms, like {a,b,c} Also, the same to go from a product of terms like a*b*c to a list like ... 2 Jul 2010 07:59

and sampling a distribution
On 6/25/10 at 7:27 AM, stone(a)geology.washington.edu (John Stone) wrote: I am trying to use RandomReal[ ] to sample from bins of different widths that span the interval 0 - 1. The bin widths represent the weights I'm assigning to a family of trial solutions in an optimization problem. The aim is to sample t... 27 Jun 2010 05:15

RandomReal[] and sampling a distribution
I hope this is a simple question (perhaps too simple for the archives, which I did search). Thanks in advance for any help. I am trying to use RandomReal[ ] to sample from bins of different widths that span the interval 0 - 1. The bin widths represent the weights I'm assigning to a family of trial solutions ... 26 Jun 2010 03:18

Display question
I have a Graphics3D with various separate elements. Some elements can be made to appear or not. If I omit elements that range beyond the others, the display rescales so that the remaining ones fill the allotted display size. I would like all displays to appear at the same scale and in the same position in the d... 26 Jun 2010 03:18

Replacement rule limitations
Several responders have told me that replacement rules are the way to simplify complex expressions and to reduce redundant computations (?). So let's try an arbitrary expression as a very simple example of something that could be much more complicated: exp = 1/Sqrt[ x^2+y^2+z^2] - (x^2+y^2+z^2) + (x^2+y^... 26 Jun 2010 03:18

Image processing Questions
Hello to all, I have two questions related to image processing. First question : I have some pictures taken with my digital camera and on the pictures I have the date in red numbers on them. I would like to erase those numbers from the pictures. I tried the procedure described on Wolfram web site about image ... 27 Jun 2010 05:15

Reducible Trinomials How to do quickest algoritm
Dear Mathethica Gurus, I'm looking for quick prcedure for finding trinoamials x^n +Ax +B for large {n,50,1000} range which have cubic unreducible factor (x^3+p x^2+q x+r). My prcedure is ver slowly and for range n 183-190 need whole day Here is Timing[aa = {}; Do[Print[n]; kk = CoefficientList[ Poly... 25 Jun 2010 07:42