This is literally a follow-up to part of Mr.Wizard's answer to: Plot, extract data to a file

Specifically in reference to

multidat = Cases[First @ gr, Line[data_] :> data, -4];

We could then export each part to a separate file like this:

Export["file" <> IntegerString[#2] <> ".txt", #, "Table"] & ~MapIndexed~ multidat
{"file1.txt", "file2.txt", "file3.txt"}

First, may I please get confirmation that I'm correctly reading the ~s in the middle line as the infix version of

MapIndexed[Export["file" <> IntegerString[#2] <> ".txt", #, "Table"]&, multidat]


Second, is there a simple way to export multidat into a single file with the lines as pairs of columns? I.e., suppose multidat is


How would you turn that into



Admittedly, I'm not sure how Mma would handle that last row. The data I have in mind is destined for a spreadsheet-like presentation where cells can be empty. Thanks for your help!

Join[##, 2] & @@ PadRight[multidat, Automatic, ""]
 {{a1, a2, p1, p2, x1, x2}, {b1, b2, q1, q2, y1, y2}, {c1, c2, r1, r2, z1, z2}, 
 {"", "", s1, s2, "", ""}}


MapAt[ArrayPad[#, 2, ""] &, Join[##, 2] & @@ multidat, {-1}]
 {{a1, a2, p1, p2, x1, x2}, {b1, b2, q1, q2, y1, y2}, {c1, c2, r1, r2, z1, z2},
  {"", "", s1, s2, "", ""}}

Firstly, you are right about Infix as a very short experiment can verify. I will not comment on this further.

x ~ f ~ y === f[x, y]

Regarding the reshaping of your data, let me walk you through a possible solution.

l = {
  {{a1, a2}, {b1, b2}, {c1, c2}},
  {{p1, p2}, {q1, q2}, {r1, r2}, {s1, s2}},
  {{x1, x2}, {y1, y2}, {z1, z2}}

Firstly, you probably will want to pad the list, such that the array is rectangular. I suggest here the padding {"", ""}. However, other paddings might be more suitable for your problem.

lPadded = PadRight[#, Max[Length[#] & /@ l], {{"", ""}}] & /@ l;

Then you can use Flatten to transpose everything to the form you want.

lReshaped = Flatten[lPadded, {{2}, {1, 3}}];

Finally, you can export the resulting list.

Export["mydata.csv", lReshaped]

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.