---
name: "claghe.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/claghe.f"
---

# claghe.f(3)

## NAME

TESTING/MATGEN/claghe.f

## SYNOPSIS

### Functions/Subroutines

subroutine **claghe** (n, k, d, a, lda, iseed, work, info)\
 **CLAGHE**

## Function/Subroutine Documentation

### subroutine claghe (integer n, integer k, real, dimension( \* ) d, complex, dimension( lda, \* ) a, integer lda, integer, dimension( 4 ) iseed, complex, dimension( \* ) work, integer info)

**CLAGHE**

**Purpose:**

```
!>
!> CLAGHE generates a complex hermitian matrix A, by pre- and post-
!> multiplying a real diagonal matrix D with a random unitary matrix:
!> A = U*D*U'. The semi-bandwidth may then be reduced to k by additional
!> unitary transformations.
!>
```

**Parameters**

*N*

```
!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!>
```

*K*

```
!>          K is INTEGER
!>          The number of nonzero subdiagonals within the band of A.
!>          0 <= K <= N-1.
!>
```

*D*

```
!>          D is REAL array, dimension (N)
!>          The diagonal elements of the diagonal matrix D.
!>
```

*A*

```
!>          A is COMPLEX array, dimension (LDA,N)
!>          The generated n by n hermitian matrix A (the full matrix is
!>          stored).
!>
```

*LDA*

```
!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= N.
!>
```

*ISEED*

```
!>          ISEED is INTEGER array, dimension (4)
!>          On entry, the seed of the random number generator; the array
!>          elements must be between 0 and 4095, and ISEED(4) must be
!>          odd.
!>          On exit, the seed is updated.
!>
```

*WORK*

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

*INFO*

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

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **101** of file **claghe.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.