math domain error

[SC Zhong]

I used the Numerical modules to find the square root of a matrix and
get the "math domain error", what is it?  The matrix I have is 
1096*1096 dimension.  When I tested the program with smaller problem,
it seems to work.  Please advice.

/var/tmp/chk_overlap-> Traceback (innermost last):
  File ".//pop", line 412, in ?
    popMatrix = LdinAnalysis(alphacoefficientsMatrix)
  File ".//pop", line 345, in LdinAnalysis
    M(overlapMatrix, eigvecsT))),eigvecsTInverse)))
ValueError: math domain error


sai