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Function Reference: nanstd

statistics: s = nanstd (x)
statistics: s = nanstd (x, w)
statistics: s = nanstd (x, w, 'all')
statistics: s = nanstd (x, w, dim)
statistics: s = nanstd (x, w, vecdim)

Compute the standard deviation while ignoring NaN values.

s = nanstd (x) returns the standard deviation of x, after removing NaN values. If x is a vector, a scalar value is returned. If x is a matrix, a row vector of column standard deviations is returned. If x is a multidimensional array, nanstd operates along the first nonsingleton dimension. If a dimension contains fewer than two non-NaN values, the standard deviation is returned as 0 for a single value and as NaN when all values are NaN.

s = nanstd (x, w) specifies the normalization. When w is 0 (default), the standard deviation is normalized by N-1, where N is the number of non-NaN observations. When w is 1, it is normalized by N. w may also be a vector of nonnegative weights whose length matches the operating dimension, in which case the weighted standard deviation normalized by the sum of the weights is returned.

s = nanstd (x, w, 'all') returns the standard deviation of all elements of x, after removing NaN values. Use an empty value, w = [], to pass the default normalization.

s = nanstd (x, w, dim) operates along the dimension dim of x.

s = nanstd (x, w, vecdim) returns the standard deviation over the dimensions specified in the vector vecdim. A weight vector is not supported together with 'all' or vecdim. Any dimension in vecdim greater than ndims (x) is ignored.

See also: std, nanvar, nanmean, nansum

Source Code: nanstd

Find the column standard deviations for a matrix with missing values.

 x = magic (3);
 x([1, 6:9]) = NaN
x =

   NaN     1   NaN
     3     5   NaN
     4   NaN   NaN
 s = nanstd (x)
s =

   0.7071   2.8284      NaN

Find the row standard deviations, normalized by N instead of N-1.

 x = magic (3);
 x([1, 6:9]) = NaN
x =

   NaN     1   NaN
     3     5   NaN
     4   NaN   NaN
 s = nanstd (x, 1, 2)
s =

   0
   1
   0