Dropping NaN observations from Matrix

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Edward Johnsen
Edward Johnsen on 23 Jan 2019
Commented: Kevin Phung on 23 Jan 2019
Hey There.
So i have a matrix that has a person ID for the first column, then data in the rows for each. What i need to do is i have identified that there are some observations that are NaN, so i need to write a code that identifies which person ID have NaN observations, so that i can drop those observations from the data.
Any help could be appreciated

Answers (2)

Walter Roberson
Walter Roberson on 23 Jan 2019

Kevin Phung
Kevin Phung on 23 Jan 2019
Edited: Kevin Phung on 23 Jan 2019
if you had a matrix A and wanted to search for NaNs in each row
nanRows =[];
for i = 1:size(A,1)
if any(isnan(A(i,:))) % for each row, if any of the elements contain a NaN
nanRows(i) = i;% store that index
end
end
A(nanRows,:) = []; %remove those IDs from your matrix
if your matrix is of cell arrays, then replace parentheses with {}.
edit: before you run A(nanRows,:) =[] , you can check which IDs had Nans with just A(nanRows,1)
  2 Comments
Walter Roberson
Walter Roberson on 23 Jan 2019
No loop needed.
A(any(isnan(A),2),:) = [];
Kevin Phung
Kevin Phung on 23 Jan 2019
never noticed any() can take two arguments, that's neat! Thanks Walter.

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