# dget04.f - Man Page

TESTING/LIN/dget04.f

## Synopsis

### Functions/Subroutines

subroutine **dget04** (n, nrhs, x, ldx, xact, ldxact, rcond, resid)**DGET04**

## Function/Subroutine Documentation

### subroutine dget04 (integer n, integer nrhs, double precision, dimension( ldx, * ) x, integer ldx, double precision, dimension( ldxact, * ) xact, integer ldxact, double precision rcond, double precision resid)

**DGET04**

**Purpose:**

DGET04 computes the difference between a computed solution and the true solution to a system of linear equations. RESID = ( norm(X-XACT) * RCOND ) / ( norm(XACT) * EPS ), where RCOND is the reciprocal of the condition number and EPS is the machine epsilon.

**Parameters***N*N is INTEGER The number of rows of the matrices X and XACT. N >= 0.

*NRHS*NRHS is INTEGER The number of columns of the matrices X and XACT. NRHS >= 0.

*X*X is DOUBLE PRECISION array, dimension (LDX,NRHS) The computed solution vectors. Each vector is stored as a column of the matrix X.

*LDX*LDX is INTEGER The leading dimension of the array X. LDX >= max(1,N).

*XACT*XACT is DOUBLE PRECISION array, dimension( LDX, NRHS ) The exact solution vectors. Each vector is stored as a column of the matrix XACT.

*LDXACT*LDXACT is INTEGER The leading dimension of the array XACT. LDXACT >= max(1,N).

*RCOND*RCOND is DOUBLE PRECISION The reciprocal of the condition number of the coefficient matrix in the system of equations.

*RESID*RESID is DOUBLE PRECISION The maximum over the NRHS solution vectors of ( norm(X-XACT) * RCOND ) / ( norm(XACT) * EPS )

**Author**Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **101** of file **dget04.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dget04(3) is an alias of dget04.f(3).

Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK