Top new questions this week:

Advice for Mathematica as Mathematician's Aid

I use Mathematica mainly as an aid in symbolic attacks on problems, usually intermediate or harder and often number theoretic. While Reduce, Simplify, et al. are remarkably powerful, they of course ...

simplifying-expressions symbolic

asked by CarlEdman 47 votes answered by MarcoB 34 votes

Efficient lazy weak compositions

In Mathematica all weak k-compositions of integer n can be generated using permutations of integer partitions: ClearAll[weakCompositionsPermPart] weakCompositionsPermPart[n_Integer, ...

performance-tuning memory combinatorics partitions lazy-computations

asked by jkuczm 22 votes answered by jkuczm 21 votes

SeriesData sucks when it can. How do I keep SeriesData from sucking?

When I run Series[f[x]*Sin[x],{x,0,3}, Analytic->False] I get: f[x](x-x^3/3+O[x]^4) as expected. In FullForm, this is Times[f[x],SeriesData[x,0,List[1,0,Rational[-1,6]],1,4,1]] But ...

series-expansion expression-manipulation

asked by QuantumDot 16 votes

How to zero (or replace) the diagonal of a square matrix?

Zeroing the diagonal of a square matrix is an operation I need frequently, but somehow I still haven't managed to find an elegant solution that satisfies all these requirements: works with both ...

list-manipulation

asked by Szabolcs 14 votes answered by ciao 12 votes

How to delete subsets quickly?

I have some data like this: data = {{4, 18, 32}, {4, 23, 42}, {5, 17, 29}, {5, 18, 31}, {11, 22, 33}, {11, 23, 35}, {13, 18, 23}, {13, 23, 33}, {13, 31, 49}, {15, 22, 29}, {15, 23, 31}, ...

list-manipulation performance-tuning subset

asked by Apple 13 votes answered by m_goldberg 10 votes

How to restore corrupted files?

I have a file that I can't reopen because MMa was "Not Responding" and I had to shut it down. I found links online to this: http://support.wolfram.com/kb/12423 I executed those two instructions in a ...

notebooks

asked by Jerry Guern 13 votes answered by Lou 11 votes

Why is an Identity function needed?

Today I came across the function Identity[x] in Mathematica (documentation). The example given in the documentation uses it in Map as follows TableForm[Composition[Through, {Identity, Sqrt}] /@ {0, ...

functions core-language

asked by Bichoy 13 votes answered by jkuczm 14 votes

Greatest hits from previous weeks:

Is there an open source implementation of Mathematica-the-language?

I've seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ...

programming open-source

asked by sblom 67 votes answered by Simon 55 votes

3D surface that looks like a virus

I have been recently using Mathematica for composing animations that are part of the supplementary information of my papers. I am currently trying to build an animation that involves a viral ...

graphics animation code-request

asked by user2098 16 votes answered by Chris Degnen 18 votes

Can you answer these?

VS c# NetLink - pictureBox - MathCommand

Has anyone experiance or a running example how to use within VS C# the NetLink.UI pictureBox to plot graphics, especially using the pictureBox - "MathCommand" I use the code example below which throw ...

.netlink

asked by wezi 3 votes

ListPlot3D: generating mesh lines at hard-coded locations

I am plotting a surface specified with a set of {x,y,z} coordinates with ListPlot3D. This data set surface does not extend beyond x^2 + y^2 == constant, x==0, and y==0. I can set polar mesh lines ...

plotting mesh

asked by Eric Smoll 2 votes

notebook scrolling problem in 10.2: worse than ever? how to fix?

I use Mma notebooks to present in the classroom, so for me this is a serious problem. Before starting a class, I close all the sections, subsections, and subsubsections. During a lecture, I open ...

notebooks

asked by Alan 2 votes