rank
Reank of a matrix.
nr=rank(a)
Inputs
a Any matrix.
Outputs
nr The rank of a .


Description
For a square matrix, if the rank is less than the size of the matrix, its inverse does not exist.
Example
>>a=[1 2 3;4 5 6; 7 8 9]
>>rank(a)
         2
>>// The rank should be the same as the dimension of the range of a.
>>orth(a)
      -0.2673       0.8729
      -0.5345       0.2182
      -0.8018      -0.4364