# Routines for Estimating the Condition Number

This section describes the ScaLAPACK routines for estimating the condition number of a matrix. The condition number is used for analyzing the errors in the solution of a system of linear equations. Since the condition number may be arbitrarily large when the matrix is nearly singular, the routines actually compute the reciprocal condition number.

- p?gecon
  Estimates the reciprocal of the condition number of a general distributed matrix in either the 1-norm or the infinity-norm.
- p?pocon
  Estimates the reciprocal of the condition number (in the 1 - norm) of a symmetric / Hermitian positive-definite distributed matrix.
- p?trcon
  Estimates the reciprocal of the condition number of a triangular distributed matrix in either 1-norm or infinity-norm.

Parent topic: Computational Routines