Find NaN elements in a matrix

Hi Guys,

How can I find the exact location of NaN elements in a matrix. I work with really large arrays (size 1500*200).

How can I find which row has a NaN value in a column matrix or vice versa.?

Thanks

N

Answer 1

[Walter Roberson]

[row, col] = find(isnan(YourMatrix));

[Wayne King]

@Walter Now, that's a better way :)

[NS]

Works fine. Thanks Walter. :)

[Jaspalsingh Virdi]

Thanks for a quick help even my data was too lARGE

[Anirban Mandal]

thanks for providing an efficient solution

[Ana Paulina García]

for me this actually creates a 1x0 variable named row and another one named col. None of the variables tells me the index :(

[Whitney]

An empty result means that there are no NaNs in the martix

Answer 2

[Wayne King]

One way:

X = ones(10,4);
X(3,4) = NaN;
indices = find(isnan(X) == 1);
[I,J] = ind2sub(size(X),indices);

Answer 3

[bym]

isnan()

[NS]

This gives me just an array of 0 and 1. I need more precise info :(

Answer 4

[Elizabeth Drybrugh]

Do this to get the sum

    sum(isnan(x))

For other functions, it depends on what you actually need....