# spot02.f - Man Page

TESTING/LIN/spot02.f

## Synopsis

### Functions/Subroutines

subroutine **spot02** (uplo, n, nrhs, a, lda, x, ldx, b, ldb, rwork, resid)**SPOT02**

## Function/Subroutine Documentation

### subroutine spot02 (character uplo, integer n, integer nrhs, real, dimension( lda, * ) a, integer lda, real, dimension( ldx, * ) x, integer ldx, real, dimension( ldb, * ) b, integer ldb, real, dimension( * ) rwork, real resid)

**SPOT02**

**Purpose:**

SPOT02 computes the residual for the solution of a symmetric system of linear equations A*x = b: RESID = norm(B - A*X) / ( norm(A) * norm(X) * EPS ), where EPS is the machine epsilon.

**Parameters***UPLO*UPLO is CHARACTER*1 Specifies whether the upper or lower triangular part of the symmetric matrix A is stored: = 'U': Upper triangular = 'L': Lower triangular

*N*N is INTEGER The number of rows and columns of the matrix A. N >= 0.

*NRHS*NRHS is INTEGER The number of columns of B, the matrix of right hand sides. NRHS >= 0.

*A*A is REAL array, dimension (LDA,N) The original symmetric matrix A.

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

*X*X is REAL array, dimension (LDX,NRHS) The computed solution vectors for the system of linear equations.

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

*B*B is REAL array, dimension (LDB,NRHS) On entry, the right hand side vectors for the system of linear equations. On exit, B is overwritten with the difference B - A*X.

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

*RWORK*RWORK is REAL array, dimension (N)

*RESID*RESID is REAL The maximum over the number of right hand sides of norm(B - A*X) / ( norm(A) * norm(X) * EPS ).

**Author**Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **125** of file **spot02.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page spot02(3) is an alias of spot02.f(3).

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