---
name: "ztrttp.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/ztrttp.f"
---

# ztrttp.f(3)

## NAME

SRC/ztrttp.f

## SYNOPSIS

### Functions/Subroutines

subroutine **ztrttp** (uplo, n, a, lda, ap, info)\
 **ZTRTTP** copies a triangular matrix from the standard full format (TR) to the standard packed format (TP).

## Function/Subroutine Documentation

### subroutine ztrttp (character uplo, integer n, complex\*16, dimension( lda, \* ) a, integer lda, complex\*16, dimension( \* ) ap, integer info)

**ZTRTTP** copies a triangular matrix from the standard full format (TR) to the standard packed format (TP).

**Purpose:**

```
!>
!> ZTRTTP copies a triangular matrix A from full format (TR) to standard
!> packed format (TP).
!>
```

**Parameters**

*UPLO*

```
!>          UPLO is CHARACTER*1
!>          = 'U':  A is upper triangular;
!>          = 'L':  A is lower triangular.
!>
```

*N*

```
!>          N is INTEGER
!>          The order of the matrices AP and A.  N >= 0.
!>
```

*A*

```
!>          A is COMPLEX*16 array, dimension (LDA,N)
!>          On entry, the triangular matrix A.  If UPLO = 'U', the leading
!>          N-by-N upper triangular part of A contains the upper
!>          triangular part of the matrix A, and the strictly lower
!>          triangular part of A is not referenced.  If UPLO = 'L', the
!>          leading N-by-N lower triangular part of A contains the lower
!>          triangular part of the matrix A, and the strictly upper
!>          triangular part of A is not referenced.
!>
```

*LDA*

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

*AP*

```
!>          AP is COMPLEX*16 array, dimension ( N*(N+1)/2 ),
!>          On exit, 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(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
!>          if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=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 **103** of file **ztrttp.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.