covariance calculation of a square matrix of any size

if cov command is directly aplied to a cameraman image for 3 by 3 matrix .the o/p is not obtained ???

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Error using ==> bsxfun Mixed integer class inputs are not supported.

Error in ==> cov at 93 xc = bsxfun(@minus,x,sum(x,1)/m); % Remove mean

Error in ==> Untitled at 12 d=cov(g);

what will be the reason

Answer 1

[Walter Roberson]

cov() only works on floating point inputs. Use cov(double(g))

[Hemal]

thanks i also use this