function [xc, xm] = center(x)%CENTER	  Centers data by subtraction of the mean.%%    [XC, XM] = CENTER(X) centers the data in X by subtraction of the%    mean XM. If X contains NaNs, indicating missing values, the mean%    of X is computed from the available data.%%    See also NANMEAN, MEAN.  error(nargchk(1,1,nargin))          % check number of input arguments   if ndims(x) > 2,  error('X must be vector or 2-D array.'); end    % if x is a vector, make sure it is a row vector  if length(x)==prod(size(x))             x   = x(:);                           end   [m,n] = size(x);  % get mean of x  if any(any(isnan(x)))               % there are missing values in x    xm  = nanmean(x);  else                                % no missing values    xm  = mean(x);  end  % remove mean  xc    = x - repmat(xm, m, 1);