# clauum.f man page

clauum.f —

## Synopsis

### Functions/Subroutines

subroutineclauum(UPLO, N, A, LDA, INFO)CLAUUMcomputes the product UUH or LHL, where U and L are upper or lower triangular matrices (blocked algorithm).

## Function/Subroutine Documentation

### subroutine clauum (characterUPLO, integerN, complex, dimension( lda, * )A, integerLDA, integerINFO)

**CLAUUM** computes the product UUH or LHL, where U and L are upper or lower triangular matrices (blocked algorithm).

**Purpose:**

```
CLAUUM computes the product U * U**H or L**H * L, where the triangular
factor U or L is stored in the upper or lower triangular part of
the array A.
If UPLO = 'U' or 'u' then the upper triangle of the result is stored,
overwriting the factor U in A.
If UPLO = 'L' or 'l' then the lower triangle of the result is stored,
overwriting the factor L in A.
This is the blocked form of the algorithm, calling Level 3 BLAS.
```

**Parameters:**

*UPLO*

```
UPLO is CHARACTER*1
Specifies whether the triangular factor stored in the array A
is upper or lower triangular:
= 'U': Upper triangular
= 'L': Lower triangular
```

*N*

```
N is INTEGER
The order of the triangular factor U or L. N >= 0.
```

*A*

```
A is COMPLEX array, dimension (LDA,N)
On entry, the triangular factor U or L.
On exit, if UPLO = 'U', the upper triangle of A is
overwritten with the upper triangle of the product U * U**H;
if UPLO = 'L', the lower triangle of A is overwritten with
the lower triangle of the product L**H * L.
```

*LDA*

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

*INFO*

```
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value
```

**Author:**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Date:**

September 2012

Definition at line 103 of file clauum.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

clauum(3) is an alias of clauum.f(3).