---
name: "cspt02.f"
section: "3"
platform: "linux"
package: "lapack-doc"
version: "3.12.1-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/cspt02.f"
---

# cspt02.f(3)

## NAME

TESTING/LIN/cspt02.f

## SYNOPSIS

### Functions/Subroutines

subroutine **cspt02** (uplo, n, nrhs, a, x, ldx, b, ldb, rwork, resid)\
 **CSPT02**

## Function/Subroutine Documentation

### subroutine cspt02 (character uplo, integer n, integer nrhs, complex, dimension( \* ) a, complex, dimension( ldx, \* ) x, integer ldx, complex, dimension( ldb, \* ) b, integer ldb, real, dimension( \* ) rwork, real resid)

**CSPT02**

**Purpose:**

```
!>
!> CSPT02 computes the residual in the solution of a complex symmetric
!> system of linear equations  A*x = b  when packed storage is used for
!> the coefficient matrix.  The ratio computed is
!>
!>    RESID = norm( B - A*X ) / ( norm(A) * norm(X) * EPS).
!>
!> where EPS is the machine precision.
!>
```

**Parameters**

*UPLO*

```
!>          UPLO is CHARACTER*1
!>          Specifies whether the upper or lower triangular part of the
!>          complex 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 COMPLEX array, dimension (N*(N+1)/2)
!>          The original complex symmetric matrix A, stored as a packed
!>          triangular matrix.
!>
```

*X*

```
!>          X is COMPLEX 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 COMPLEX 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 **121** of file **cspt02.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.