---
name: "cla_porcond_x.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/cla_porcond_x.f"
---

# cla\_porcond\_x.f(3)

## NAME

SRC/cla\_porcond\_x.f

## SYNOPSIS

### Functions/Subroutines

real function **cla\_porcond\_x** (uplo, n, a, lda, af, ldaf, x, info, work, rwork)\
 **CLA\_PORCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for Hermitian positive-definite matrices.

## Function/Subroutine Documentation

### real function cla\_porcond\_x (character uplo, integer n, complex, dimension( lda, \* ) a, integer lda, complex, dimension( ldaf, \* ) af, integer ldaf, complex, dimension( \* ) x, integer info, complex, dimension( \* ) work, real, dimension( \* ) rwork)

**CLA\_PORCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for Hermitian positive-definite matrices.

**Purpose:**

```
!>
!>    CLA_PORCOND_X Computes the infinity norm condition number of
!>    op(A) * diag(X) where X is a COMPLEX vector.
!>
```

**Parameters**

*UPLO*

```
!>          UPLO is CHARACTER*1
!>       = 'U':  Upper triangle of A is stored;
!>       = 'L':  Lower triangle of A is stored.
!>
```

*N*

```
!>          N is INTEGER
!>     The number of linear equations, i.e., the order of the
!>     matrix A.  N >= 0.
!>
```

*A*

```
!>          A is COMPLEX array, dimension (LDA,N)
!>     On entry, the N-by-N matrix A.
!>
```

*LDA*

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

*AF*

```
!>          AF is COMPLEX array, dimension (LDAF,N)
!>     The triangular factor U or L from the Cholesky factorization
!>     A = U**H*U or A = L*L**H, as computed by CPOTRF.
!>
```

*LDAF*

```
!>          LDAF is INTEGER
!>     The leading dimension of the array AF.  LDAF >= max(1,N).
!>
```

*X*

```
!>          X is COMPLEX array, dimension (N)
!>     The vector X in the formula op(A) * diag(X).
!>
```

*INFO*

```
!>          INFO is INTEGER
!>       = 0:  Successful exit.
!>     i > 0:  The ith argument is invalid.
!>
```

*WORK*

```
!>          WORK is COMPLEX array, dimension (2*N).
!>     Workspace.
!>
```

*RWORK*

```
!>          RWORK is REAL array, dimension (N).
!>     Workspace.
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **121** of file **cla\_porcond\_x.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.