replace values with nans

I have a matrix data. i applied a condition and i get the idx. i want to replace that idx values with Nans.

plz suggest the process for this.

Thanks....

Answer 1

[madhan ravi]

data(idx)=NaN

[Leela Sai Krishna]

thanks it works.

actually i want to replace values in matrices with nans whose idx is 1

Answer 2

[Jos (10584)]

Take a look at logical indexing or the function ind2sub

M = randi(10,8,6)
% use indices of elements for which condition is true
idx = find(M > 8)
M(sub2ind(size(M), idx)) = NaN 
% use logical indexing (easier in many cases)
M(M < 3) = 999