The old Google Groups will be going away soon, but your browser is incompatible with the new version.
comp . soft-sys . math . mathematica
This is a Usenet group - learn more
Find or start a Google Group about mathematica.
Group info
 Language: English Group categories: Computers More group info »
Active older topics
39 new of 39 - May 19
2 new of 2 - May 16
4 new of 4 - May 15
4 new of 4 - May 14
1 new of 1 - May 14
3 new of 3 - May 14
1 new of 1 - May 14
5 new of 5 - May 13
1 new of 1 - May 12
2 new of 2 - May 12
Discussions
 View: Topic list, Topic summary Topics 1 - 10 of 41432  Older »
 Description: Mathematica discussion group. (Moderated)

 Repeated Integrals I'm fairly new to Mathematica and I'm trying to create an expression for a set of nested integrals. The innermost integral is int[0,x,L(y,a)g(y),dy] Where g(y) is an arbitrary function and a is a parameter. The next integral is int[0,w,L(x,b)h(x,a),dx] Where b is a parameter and h(x,a) is the result of the previous integral.... more » By briank...@gmail.com  - 5:46am - 1 new of 1 message

 skipping some i, j , ... values in Table Hi, Suppose I need a list, Flatten[Table[something[i,j],{ i,10},{j,10}]], where some combinations of indices i and j are voluntarily missing under a known condition (for example, stupid I know, when i+j is a prime). How can I do that ? Thanks in advance, ahautot By Andre Hautot  - May 18 - 7 new of 7 messages

 writing real numeric data to file in scientific form I think what you are looking for is FortranForm[]. I use it exclusively now. Here is writing it out and reading it back... m=ToString@FortranForm[0.00000 3] ToExpression[StringReplace[m," e-"-> "*10^"]] If you write your data to CSV format, it can be read back in with Scientific notation without issue. CSV format really rocks with Mathematica. I still use ToString@FortranForm[] for formatting prior to writing to CSV. On read, you will get numbers back and don't need the second line above.... more » By McHale, Paul  - May 18 - 1 new of 1 message

 Comment about SetDirectory[] I have often wondered whether to use: SetDirectory[NotebookDirectory []] Export["TestResultTime.txt", mTimeDiff, "Table"] or Export[NotebookDirectory[] <> "TestResultTime.txt", mTimeDiff, "Table"] I have left Mathematica open for 2 days as it was running a very long test. Maybe something became corrupted. The first method did not work. It appears SetDirectory[] simply stopped functioning. Personally, I think the second method is better since it is atomic in nature. It doesn't depend on any stateful settings.... more » By McHale, Paul  - May 18 - 1 new of 1 message

 2x2 determinant bug in math 9.0.0.0 Hi all, caution if you compute matrix determinants in Mathematica 9.0.0.0! You'll find below a 2x2 matrix composed of symbolic rational fractions. Compare Det[M] and the expected expression M[[1, 1]] M[[2, 2]] - M[[1, 2]] M[[2, 1]] . To your surprise, you'll find different results if you use Mathematica 9.0.0.0. Affected versions are independent of Linux/Mac/Win OS:... more » By Vivien Lecomte  - May 18 - 2 new of 2 messages

 Overriding the single quote (') The Verilog "programming" language provide a compact way to describe and work with digital circuits. The language features a nifty syntax for representing bits. For example 3'b101 is the 3 bit unsigned binary number 101. 3'd5 is the same binary number but represented as the decimal 5. I wanted to set up an expression in Mathematica such as f[3'b101] rather than the more verbose f["3'b101"].... more » By Lawrence Walker  - May 17 - 2 new of 2 messages

 How do you control evaluation when using apply? Hello, both of your versions work fine in M9. Here is even a shorter one: In[]:= jacFun[func_, vars_] := Module[{f}, f = Function @@ {{x, y}, D[func, {vars}]}; f @@ # &] In[]:=jacFun[{Sin[x y], Cos[x + y]}, {x, y}][{10, 2}] Out[]:={{2 Cos[20], 10 Cos[20]}, {-Sin[12], -Sin[12]}}... more » By Christoph Lhotka  - May 17 - 1 new of 1 message

 How do you control evaluation when using apply? Why does this work In[0]: = jacobianFunction[func_, vars_List] := Module[{f}, f = Function[Evaluate[vars], Evaluate[D[func, {vars}]]]; f ]; jacobianFunction[{Sin[x y], Cos[x + y]}, {x, y}] @@ {10, 2} out[0]:= {{2 Cos[20], 10 Cos[20]}, {-Sin[12], -Sin[12]}} But this does not (the goal is to make the function take a point as an... more » By Brentt  - May 16 - 2 new of 2 messages

 What's the largest index-known prime? On odd-prime-position-constant. I'm going to build some projects to do primes fast computing. [link] [link] This code generate part of odd-prime-position-constant: pr = 0; x = 2*pr*2^32 - 1; For[k = 0, k < 4096, k++, t = Table[x += 2; If[PrimeQ[x], 1, 0], {n, 0, 2^20 - 1}];... more » By a boy  - May 15 - 1 new of 1 message

 can't get InputField to work inside a While command I need to be able to input parameters for an a-priori indeterminate number of cases. The way I've been trying to do this is by using a While statement containing InputFields, one of which asks if there are to be more cases to deal with. If not, the previously True logical 'test' for While is reset to False.... more » By Dushan Mitrovich  - May 14 - 4 new of 4 messages

 1 - 10 of 41432   « Newer | Older »