---
name: "cpotrf"
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/cpotrf.f"
---

# cpotrf(3)

Part of [cpotrf.f(3)](/cpotrf.f/3.md).

## NAME

SRC/cpotrf.f

## SYNOPSIS

### Functions/Subroutines

subroutine **cpotrf** (uplo, n, a, lda, info)\
 **CPOTRF**

## Function/Subroutine Documentation

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

**CPOTRF**

**Purpose:**

```
!>
!> CPOTRF computes the Cholesky factorization of a complex Hermitian
!> positive definite matrix A.
!>
!> The factorization has the form
!>    A = U**H * U,  if UPLO = 'U', or
!>    A = L  * L**H,  if UPLO = 'L',
!> where U is an upper triangular matrix and L is lower triangular.
!>
!> This is the block version of the algorithm, calling Level 3 BLAS.
!>
```

**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 order of the matrix A.  N >= 0.
!>
```

*A*

```
!>          A is COMPLEX array, dimension (LDA,N)
!>          On entry, the Hermitian 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.
!>
!>          On exit, if INFO = 0, the factor U or L from the Cholesky
!>          factorization A = U**H*U or A = L*L**H.
!>
```

*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 = -i, the i-th argument had an illegal value
!>          > 0:  if INFO = i, the leading principal minor of order i
!>                is not positive, and the factorization could not be
!>                completed.
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **106** of file **cpotrf.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.