create a subset of data matrix randomly

i have a complete matrix of dimension 116X17. I need a half of the elements ie 896 elememens of the matrix are created randomly with all other cell have NaN value.

[Guillaume]

What does created randomly mean? What range of values should be created?

What is the point of the original matrix, if your new matrix is either completely random numbers or NaN?

Answer 1

[KSSV]

A = rand(116,17) ;  % your data 
N = 896 ;
iwant = NaN(size(A)) ;
idx = randperm(numel(A),N) ;
iwant(idx) = A(idx) ;

[KAKOLI DEY]

your answer is partially fulfill my requirement ,Random geneneration of NaN values are OK,I want generate matrix original value instead of random number.

[Jan]

@KAKOLI DEY: Then use your original matrix instead of A. The rand was used here only to create example data.

@KSSV: +1.