sqrt16.f - Man Page

TESTING/LIN/sqrt16.f

Synopsis

Functions/Subroutines

subroutine sqrt16 (trans, m, n, nrhs, a, lda, x, ldx, b, ldb, rwork, resid)
SQRT16

Function/Subroutine Documentation

subroutine sqrt16 (character trans, integer m, 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)

SQRT16

Purpose:

``` SQRT16 computes the residual for a solution of a system of linear
equations  A*x = b  or  A'*x = b:
RESID = norm(B - A*X) / ( max(m,n) * norm(A) * norm(X) * EPS ),
where EPS is the machine epsilon.```
Parameters

TRANS

```          TRANS is CHARACTER*1
Specifies the form of the system of equations:
= 'N':  A *x = b
= 'T':  A'*x = b, where A' is the transpose of A
= 'C':  A'*x = b, where A' is the transpose of A```

M

```          M is INTEGER
The number of rows of the matrix A.  M >= 0.```

N

```          N is INTEGER
The number of 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 M x N matrix A.```

LDA

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

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.  If TRANS = 'N',
LDX >= max(1,N); if TRANS = 'T' or 'C', LDX >= max(1,M).```

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.  IF TRANS = 'N',
LDB >= max(1,M); if TRANS = 'T' or 'C', LDB >= max(1,N).```

RWORK

`          RWORK is REAL array, dimension (M)`

RESID

```          RESID is REAL
The maximum over the number of right hand sides of
norm(B - A*X) / ( max(m,n) * norm(A) * norm(X) * EPS ).```
Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 131 of file sqrt16.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page sqrt16(3) is an alias of sqrt16.f(3).

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