Reshape multiple dat files

Hello all,

I have a large number of dat files in which multiple variables are arranged in a single column one after the other. Each variable is separated by several -9.

Like so: 1 2 3 4 -9 -9 -9 -9 5 6 7 8 -9 -9 -9 -9 9 10 11 12 13 ...

Now, I want to reshape them so I have one variable per column and get rid of the -9. Like so:

A B C

1 5 9

2 6 10

3 7 11

4 8 12

Please note that the number of variables, their length and the number of -9 between them may change.

Any ideas ?

Answer 1

[Star Strider]

One approach:

V = [1 2 3 4 -9 -9 -9 -9 5 6 7 8 -9 -9 -9 -9 9 10 11 12];
Vr = V;
Vr(Vr==-9) = [];
Vr = reshape(Vr(:), [], 3)
VrT = table(Vr(:,1),Vr(:,2),Vr(:,3), 'VariableNames',{'A','B','C'})

Vr =
     1     5     9
     2     6    10
     3     7    11
     4     8    12

VrT =

    4×3 table

      A    B    C 
      _    _    __

      1    5     9
      2    6    10
      3    7    11
      4    8    12

Answer 2

[Guillaume]

I'm assuming that within the same file, the number of -9 between each variable is constant:

V = [1 2 3 4 -9 -9 -9 -9 5 6 7 8 -9 -9 -9 -9 9 10 11 12]'  %column vector as stated
nines = find(V == -9);                     %location of all nines
startnines = nines(diff([0; nines]) > 1);  %start locations of -9 sequences
endnines = nines(diff([nines; Inf]) > 1);  %end locations of -9 sequences
Vr = [V; repmat(-9, endnines(1) - startnines(1) + 1, 1)];  %append -9 after last variable
Vr = reshape(Vr, endnines(1), []);          %reshape into columns of variables
Vr(startnines(1):endnines(1), :) = []       %delete -9

edit: Actually it's not much more complicated if the number of -9 between each variable is not even constant within the same file:

V = [1 2 3 4 -9 -9 -9 -9 5 6 7 8 -9 -9 -9 -9 9 10 11 12]'  %column vector as stated
nines = find(V == -9);                     %location of all nines
startnines = nines(diff([0; nines]) > 1);  %start locations of -9 sequences
endnines = nines(diff([nines; Inf]) > 1);  %end locations of -9 sequences
seqlengths = diff([1; reshape([startnines, endnines+1]', [], 1); numel(V)+1]);
Vr = mat2cell(V, seqlengths, 1);
Vr = [Vr{1:2:end}]