# cond

## Purpose

Matrix condition number.

## Synopsis

    c = cond(X)

## Description

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.

## Algorithm

`cond` uses the singular value decomposition, `svd`.

## See Also

    condest, norm, rank, rcond, svd

## References

[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.