Mathematica

Puzzlement about DumpSave (and/or DownValues)
This looks like a bug to me, but I know appearances can deceive! Cell 1 below defines two symbols: foo and list. After evaluation of Cell1, I thought Cell 2 would dump and restore symbol 'foo' but it does not. Now here is puzzlement: If you change DumpSave's second argument from 'list' to '{foo}', the code works ... 5 Jun 2010 08:07

discretized Laplacian or linear inverse problem with extremely simple
Hello! There are: A n*n matrix x n*1 matrix==column b n*1 matrix==column and the well known equation A.x==b I know columns x and b I want Mathematica to derive matrix A Of course, generally, this is a complicated problem, but in my case all values of matrix A are small (less than 20 in absolute value) ... 4 Jun 2010 08:06

Export
Hi, How can I accomplish the following: mylist = {1,2,3,4}; I would like to "export" my list to a data file so that inside the data file it would look like: 1,2,3,4 on the first line... I then need to be able to read this back in using import.. I also need the ability to "Append" to this data file ano... 10 Jun 2010 08:52

difficulty in calculating first two terms of an
Clear[p]; p[x_, n_] = (-1 + x)^(n + 1)* Sum[Binomial[n + 2*k, 2*k]*x^k, {k, 0, Infinity}] // FullSimplify ((1/2)*(-(1 - Sqrt[x])^(n + 1) - (Sqrt[x] + 1)^(n + 1))* (x - 1)^n)/(1 - x)^n Simplify[(1 - x)^-n (x - 1)^n == (-1)^n, Element[n, Integers]] True p[x_, n_Integer] = ((1/2... 3 Jun 2010 06:44

translating function to dynamicmodule scope
I sometimes import data sets, generate theoretical curves based on some expressions and then plot chi-square plots over a fairly large parameter space. The way I had been doing this was using a dynamic file browser and then something along the lines of the following ***some type of grid or nice frame***, {FileName... 3 Jun 2010 06:44

Slight changes of the existing StyleSheet
Dear Community, I like the JournalArticle StyleSheet, but I need to have it with its fonts larger, so that one can read then not only on-screen, but also as a hard copy. This is a must in our company. What should I do to only increase the font sizes (either all or most of them)? I would like to do it so, that... 2 Jun 2010 02:14

PDE, laplace, exact, should be simple...
forgive the simplicity of this: D[u[x, y], {x, 2}] + D[u[x, y], {y, 2}] == 0 BCs={u[0, y] == 0, u[x, 0] == 0, u[1, y] == 0, u[x, 1] === Sin[=F0 x]} DSolve etc, etc, etc... A solution is Sin[Pi x] Sinh[Pi y] How can I get mathematica to come up with this gem ? thanks, and sorry again for an... 10 Jun 2010 08:52

How do make the output of Graphics[ ] print out in "Inch" units ?
I want to use Mathematica to for some sheet metal layout applications where the output is printed out on paper. A simple example would be a 3,4,5 triangle where the sides are 3 inches, 4 inches, and 5 inches. Graphics[{Line[{{1, 1}, {4, 1}, {4, 5}, {1, 1}}]}] would produce the triangle, but how can I guarantee t... 2 Jun 2010 02:14

difficulty in calculating first two terms of an infinite sum
The zero and one terms for the binomial version exist, but this Narayana number analog has difficulty in Mathematica on the n=1 term : Clear[p, x] p[x_, n_] = (1 - x)^(2*n - 1)*Sum[(Binomial[2*k + n, 2*k] Binomial[2*k + n, 1 + 2*k]/(2*k + n))*x^k, {k, 0, Infinity}] Table[FullSimplify[ExpandAll[p[x, n]]], {n... 2 Jun 2010 02:14

Assigning values to a list.
Hi Guys, I am a newbie to mathematica..Is there anyway to read values from 2 lists {n by 1} and {n by 1} to a new list {n by 2} without using loops.. eg say you have x = {1,3,5} any y = {2,4,6}, I will need a new list z ={{1,2},{3,4},{5,6}}.. Thanks in advance. ... 3 Jun 2010 05:39