logm
Matrix logarithm function.
y=logm(a)
Inputs
a A square matrix.
Outputs
y A square matrix of the same size as a which is the matrix logarithm of the input.


Example
>>a=[1 2 3 ; 4 5 6; 1.5 .5 1]
>>a
    1.0000    2.0000    3.0000
    4.0000    5.0000    6.0000
    1.5000    0.5000    1.0000

>>b=expm(a)
>>b
  413.6404  447.4972  602.2533
 1078.9745 1170.6497 1572.4667
  178.4732  192.3656  260.3237

>>c=logm(b) // note that logm(expm(a))=a in this case
>>c
    1.0000    2.0000    3.0000
    4.0000    5.0000    6.0000
    1.5000    0.5000    1.0000