time   calls  line
                  1 function y = std(varargin)
                  2 %STD Standard deviation.
                  3 %   For vectors, Y = STD(X) returns the standard deviation.  For matrices,
                  4 %   Y is a row vector containing the standard deviation of each column.  For
                  5 %   N-D arrays, STD operates along the first non-singleton dimension of X.
                  6 %
                  7 %   STD normalizes Y by (N-1), where N is the sample size.  This is the
                  8 %   sqrt of an unbiased estimator of the variance of the population from
                  9 %   which X is drawn, as long as X consists of independent, identically
                 10 %   distributed samples.
                 11 %
                 12 %   Y = STD(X,1) normalizes by N and produces the square root of the second
                 13 %   moment of the sample about its mean.  STD(X,0) is the same as STD(X).
                 14 %
                 15 %   Y = STD(X,FLAG,DIM) takes the standard deviation along the dimension
                 16 %   DIM of X.  Pass in FLAG==0 to use the default normalization by N-1, or
                 17 %   1 to use N.
                 18 %
                 19 %   Example: If X = [4 -2 1
                 20 %                    9  5 7]
                 21 %     then std(X,0,1) is [3.5355 4.9497 4.2426] and std(X,0,2) is [3.0
                 22 %                                                                  2.0]
                 23 %   Class support for input X:
                 24 %      float: double, single
                 25 %
                 26 %   See also COV, MEAN, VAR, MEDIAN, CORRCOEF.
                 27 
                 28 %   Copyright 1984-2004 The MathWorks, Inc.
                 29 %   $Revision: 5.25.4.2 $  $Date: 2004/03/09 16:16:30 $
                 30 
                 31 % Call var(x,flag,dim) with as many of those args as are present.
  2.25    1673   32 y = sqrt(var(varargin{:}));