How to segment one row matrix into multiple row matrix

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Hi, I do have for example this matrix [ 3 6 4 5 6 NaN 8 9 10 NaN NaN NaN 13 14 5 6 0 1 NaN NaN 2 3 NaN NaN NaN 9 1 5 NaN 2 8 NaN] and i would like to have matrix where each row would be each segment of values.
I mean like:
3 6 4 5 6
8 9 10
13 14 5 6 0 1
2 3
9 1 5
2 8

Answers (1)

David Fletcher
David Fletcher on 10 Apr 2021
Ultimately you can't have a matrix of the segments since they are potentially of different lengths - you could have a cell array of them though. Something like this:
A=[ 3 6 4 5 6 NaN 8 9 10 NaN NaN NaN 13 14 5 6 0 1 NaN NaN 2 3 NaN NaN NaN 9 1 5 NaN 2 8 NaN]
nanLoc=isnan(A);
partial=[];
vecCount=1;
iter=1;
vectors={};
while iter<=numel(A)
if (nanLoc(iter)==1)
if ~isempty(partial)
vectors{vecCount} = partial;
vecCount=vecCount+1
end
partial=[];
else
partial=[partial A(iter)];
end
iter=iter+1;
end
Running it gives
vectors =
1×6 cell array
{[3 6 4 5 6]} {[8 9 10]} {[13 14 5 6 0 1]} {[2 3]} {[9 1 5]} {[2 8]}
  2 Comments
Lukas Poviser
Lukas Poviser on 10 Apr 2021
And would it be possible to interpolate vectors? So every vector would have 100 values. And final size of matrice would be M(number of segments) x 100.
David Fletcher
David Fletcher on 10 Apr 2021
If you wished to pad them to the same length and store them in a matrix, then yes you could do that. However, you (presumably) could not know beforehand what size the segments would need to be padded to - saying that some trivial analysis of the nanLoc vector could give you such a value. Also whatever you used to pad the vectors couldn't be a value that would naturally occur in the vector (or you would have no way of knowing whether a pad value was genuine or naturally occuring). One final thing, as it often the case I have just noticed a problem in the code I've provided - if the original array doesn't end in a NaN, the final partial value will fail to be written to vectors cell array - but then I guess it does leave something for you to do...

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