# Refining the Solution and Estimating Its Error

This section describes the ScaLAPACK routines for refining the computed solution of a system of linear equations and estimating the solution error. You can call these routines after factorizing the matrix of the system of equations and computing the solution (see Routines for Matrix Factorization and Solving Systems of Linear Equations).

- p?gerfs
  Improves the computed solution to a system of linear equations and provides error bounds and backward error estimates for the solution.
- p?porfs
  Improves the computed solution to a system of linear equations with symmetric/Hermitian positive definite distributed matrix and provides error bounds and backward error estimates for the solution.
- p?trrfs
  Provides error bounds and backward error estimates for the solution to a system of linear equations with a distributed triangular coefficient matrix.

Parent topic: Computational Routines