How can I center a matrix containing NaN values?

I have a matrix of size 72x144. It contains many NaN values, but also contains numeric values. I have been successful in the past at centering matrices containing only numeric values using the following code:

xctr=bsxfun(@minus, x, sum(x)/size(x, 1));

However, this seems to output a matrix with all NaN values, rather than giving me many NaN values, and also the centered numerical values. How can I center the data without turning everything into NaN?

[Image Analyst]

What does it mean to "center" a matrix with nan's sprinkled throughout it? Can you give a small example of the input matrix and desired output matrix?

[Patrick]

ex:

X = [ NaN NaN NaN | 6 4 2 | NaN 4 NaN ]

want:

xctr = [ NaN NaN NaN | 2 0 -2 | NaN 0 NaN ]

Answer 1

[Azzi Abdelmalek]

if you statistic toolbox

xctr=bsxfun(@minus, x, nansum(x)/size(x, 1));

[Patrick]

Perfect! Thank you.