harmmean
              Compute the harmonic mean of x.
harmmean(x) returns the
 harmonic mean of the elements in x defined as
 $$ {\rm harmmean}(x) = \frac{N}{\sum_{i=1}^N \frac{1}{x_i}} $$
   where  is the length of the x vector.
 harmmean(x) returns a row
 vector with the harmonic mean of each columns in x.
 harmmean(x)
 operates along the first nonsingleton dimension of x.
  harmmean(x, "all") returns the harmonic mean of all the elements
 in x.  If x contains any 0, then the returned value is 0.
 harmmean(x, dim) returns the harmonic mean along the
 operating dimension dim of x.  Calculating the harmonic mean of
 any subarray containing any 0 will return 0.
 harmmean(x, vecdim) returns the harmonic mean over the
 dimensions specified in the vector vecdim.  For example, if x is
 a 2-by-3-by-4 array, then harmmean(x, [1 2]) returns a
 1-by-1-by-4 array.  Each element of the output array is the harmonic mean of
 the elements on the corresponding page of x.  If vecdim indexes
 all dimensions of x, then it is equivalent to harmmean (x,
 "all").  Any dimension in vecdim greater than ndims (x)
 is ignored.
 harmmean(…, nanflag) specifies whether to exclude NaN
 values from the calculation, using any of the input argument combinations in
 previous syntaxes. By default, harmmean includes NaN values in the
 calculation (nanflag has the value "includenan").  To exclude NaN
 values, set the value of nanflag to "omitnan".
Source Code: harmmean