Top new questions this week:

Dataset seems unable to handle ListDensityPlot and ListContourPlot

If I create a Dataset: dataSet = Dataset[ AssociationThread[{"a", "b", "c", "d", "e"} -> #] & /@ RandomReal[{-1, 1}, {1000, 5}] ]; It should be easy to use a plotting function on it …

plotting version-10 dataset

asked by gpap 14 votes answered by RunnyKine 14 votes

Make my data-structure atomic

Lately, and by lately I mean since version 7 or so, the number of atomic expressions in Mathematica constantly grew. In former times only the native types like integers and optimised arrays were …

data-structures

asked by halirutan 14 votes answered by Leonid Shifrin 10 votes

Bad performance of LengthWhile?

A friend of mine showed me this example, it's a test comparing LengthWhile to a self-made lengthwhile written in a direct and conventional way: lengthwhile[x_, t_] := Module[{i = 0, l = Length@x}, …

list-manipulation performance-tuning

asked by xzczd 13 votes answered by Simon Woods 14 votes

Has this implementation of FDM touched the speed limit of Mathematica?

Still, I'll use the implementation of the 1D FDTD method (you can simply understand it as a kind of explicit finite difference scheme for the Maxwell's equation) as the example. Just for completeness, …

differential-equations performance-tuning compile difference-equations

asked by xzczd 12 votes answered by Daniel Lichtblau 9 votes

Assign a randomly generated list to variable

I don't know if this is a silly question, but it really baffles me. So please help me understand this behavior. list=RandomInteger[100,100] I interpret the (silly) code above as randomly generating …

bugs random assignment

asked by Naitree 10 votes answered by rhermans 0 votes

Applying different functions to different columns of a Dataset

Suppose I have different functions: Total, Mean and Max and the following Dataset SeedRandom[0] dataSet = Dataset[AssociationThread[{"a", "b", "c", "d"} -> #] & /@ RandomReal[4, {10, 4}]] …

dataset

asked by smayhem 10 votes answered by RunnyKine 8 votes

Repeating Digits

I have written RepeatingDigits[n_Integer] := Module[{id = IntegerDigits @ n, x}, x = Differences /@ Map[Partition[id, #] &, Range[Length[id]/2]]; If[# === {}, Return @ False, x = Length @ …

list-manipulation pattern-matching algorithm sequence

asked by eldo 9 votes answered by belisarius 10 votes

Greatest hits from previous weeks:

Where can I find examples of good Mathematica programming practice?

I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't …

reference-request programming

asked by Ｊ. Ｍ. 304 votes answered by Faysal Aberkane 276 votes

Assign the results from a Solve to variable(s)

I understand Mathematica can't assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?

equation-solving assignment

asked by stevenvh 15 votes answered by Artes 10 votes

Can you answer these?

Plotting extra parametric axes

We are trying to plot a figure as below from data points. This version is a postprocessed plot (in Illustrator) just to obtain the skew axes. The rest is plotted with ListLogLogPlot[]. Any idea on how …

plotting logarithmic-scale rotation rotate

asked by Jan G. Korvink 6 votes

Font difference in mathematica 9 and 10 after export to illustrator

It seems WRI has changed the way fonts are dealt with in Mathematica 9 and 10. The following command Export["test.eps", "This is a nice formula"] yields this in Mathematica 9 (after import to …

version-9 version-10 fonts

asked by chris 2 votes

Create SQL Database on a manually specified directory

I am inserting lots of data into the preinstalled SQL Database in MM: con= OpenSQLConnection["demo"] > SQLCreateTable[con, SQLTable["anyname"], SQLcolums] > ... I am running out of disk space on my …

sql

asked by Patrick Bernhard 2 votes