---
name: "zlattp.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/zlattp.f"
---

# zlattp.f(3)

## NAME

TESTING/LIN/zlattp.f

## SYNOPSIS

### Functions/Subroutines

subroutine **zlattp** (imat, uplo, trans, diag, iseed, n, ap, b, work, rwork, info)\
 **ZLATTP**

## Function/Subroutine Documentation

### subroutine zlattp (integer imat, character uplo, character trans, character diag, integer, dimension( 4 ) iseed, integer n, complex\*16, dimension( \* ) ap, complex\*16, dimension( \* ) b, complex\*16, dimension( \* ) work, double precision, dimension( \* ) rwork, integer info)

**ZLATTP**

**Purpose:**

```
!>
!> ZLATTP generates a triangular test matrix in packed storage.
!> IMAT and UPLO uniquely specify the properties of the test matrix,
!> which is returned in the array AP.
!>
```

**Parameters**

*IMAT*

```
!>          IMAT is INTEGER
!>          An integer key describing which matrix to generate for this
!>          path.
!>
```

*UPLO*

```
!>          UPLO is CHARACTER*1
!>          Specifies whether the matrix A will be upper or lower
!>          triangular.
!>          = 'U':  Upper triangular
!>          = 'L':  Lower triangular
!>
```

*TRANS*

```
!>          TRANS is CHARACTER*1
!>          Specifies whether the matrix or its transpose will be used.
!>          = 'N':  No transpose
!>          = 'T':  Transpose
!>          = 'C':  Conjugate transpose
!>
```

*DIAG*

```
!>          DIAG is CHARACTER*1
!>          Specifies whether or not the matrix A is unit triangular.
!>          = 'N':  Non-unit triangular
!>          = 'U':  Unit triangular
!>
```

*ISEED*

```
!>          ISEED is INTEGER array, dimension (4)
!>          The seed vector for the random number generator (used in
!>          ZLATMS).  Modified on exit.
!>
```

*N*

```
!>          N is INTEGER
!>          The order of the matrix to be generated.
!>
```

*AP*

```
!>          AP is COMPLEX*16 array, dimension (N*(N+1)/2)
!>          The upper or lower triangular matrix A, packed columnwise in
!>          a linear array.  The j-th column of A is stored in the array
!>          AP as follows:
!>          if UPLO = 'U', AP((j-1)*j/2 + i) = A(i,j) for 1<=i<=j;
!>          if UPLO = 'L',
!>             AP((j-1)*(n-j) + j*(j+1)/2 + i-j) = A(i,j) for j<=i<=n.
!>
```

*B*

```
!>          B is COMPLEX*16 array, dimension (N)
!>          The right hand side vector, if IMAT > 10.
!>
```

*WORK*

```
!>          WORK is COMPLEX*16 array, dimension (2*N)
!>
```

*RWORK*

```
!>          RWORK is DOUBLE PRECISION array, dimension (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 **129** of file **zlattp.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.