Matrix condition number.
c = cond(X)
The condition number of a matrix measures the sensitivity of the solution of a system of linear equations to errors in the data. It gives an indication of the accuracy of the results from matrix inversion and linear equation solution.
cond(X) returns the 2-norm condition number, the ratio of the largest singular value of X to the smallest.
cond uses the singular value decomposition, svd.
condest, norm, rank, rcond, svd
[1] J.J. Dongarra, J.R. Bunch, C.B. Moler, and G.W. Stewart, LINPACK
User's Guide, SIAM, Philadelphia, 1979.
(c) Copyright 1994 by The MathWorks, Inc.