Linked Questions

5
votes
3answers
271 views

Manipulating list with sub-lists of different lengths

Consider the following list, which is composed of sublists with different lengths ...
97
votes
4answers
5k views

Flatten command: matrix as second argument

One thing I could never wrap my head around is how Flatten works when provided with a matrix as the second argument, and the Mathematica help isn't particularly ...
9
votes
3answers
237 views

Threading elements over corresponding elements in the second list

I often need to merge two lists like the following: $A=\{\{0.1\},\{0.2\},\ldots,\{1\}\}$ $B=\{\{x_1\},\{x_{21},x_{22},x_{23}\},\{x_{31},x_{32},x_{33}\},\ldots,x_N\}$ in a way to ideally obtain a ...
527
votes
19answers
131k views

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 ...
11
votes
2answers
6k views

How to get MATLAB data imported with the same dimensions?

I have some MATLAB image data with the following dimensions (output is from MATLAB): >> size(im) ans = 86 86 3 45 The data imports just fine ...
2
votes
1answer
103 views

Efficient creation of lists from other lists

Given the following lists: v1 = {a, c, e}; v2 = {b, d, f}; how does one efficiently create the following "combination lists"? ...
8
votes
3answers
264 views

How can I generate a $2n$-point moving maximum of a list as efficiently as MaxFilter?

This is based on the prior question, Moving maximum function?, where @rasher provided two winning solutions (i.e. clearly the most efficient): MaxFilter[list, 1] ...
2
votes
3answers
2k views

Plot a table of lists

I want to make a point plot of a table with lists in it. Assume I have data like this: data={{1,2,3,4},{5,6},{1,5},{2,4}}; and now I want to make a point plot ...
9
votes
6answers
289 views

Is there a better way to add a “key” for the list of GatherBy?

In ruby , 1.upto(10).to_a.group_by{|x| x%3} gives {1=>[1, 4, 7, 10], 2=>[2, 5, 8], 0=>[3, 6, 9]} I would like use ...
14
votes
3answers
3k views

How to add lists with unequal length?

Given lists of unequal lengths, I want to add them together element-wise, treating missing elements as zero. For example, {1, 2, 3} + {a, b} + {x} should give ...
2
votes
3answers
1k views

How to transpose unequal lists

As the titel says I want to transpose a matrix containing rows of unequal length, to be able to transport them to excel (in row form, there are too many datapoint to write them in a cell. In another ...
23
votes
5answers
1k views

MapThread over sublists of different length

I have a list which looks like this: l={{1,0,3,4},{0,2},{0,0,1,3},{1,2,0}}. Now I would like to count how many 0s the sublists contain in the first, second,... slot....
9
votes
3answers
905 views

Operations on elements of ragged lists

Suppose I have a list of lists with different lengths, sorted from longest to shortest ...