---
name: "cpotrs"
section: "3lapack"
platform: "linux"
package: "liblapack-doc"
version: "3.2.1-8"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/cpotrs/3lapack"
---

# cpotrs(3lapack)

solves a system of linear equations A\*X = B with a Hermitian positive definite matrix A using the Cholesky factorization A = U\*\*H\*U or A = L\*L\*\*H computed by CPOTRF

## NAME

CPOTRS - solves a system of linear equations A\*X = B with a Hermitian positive definite matrix A using the Cholesky factorization A = U\*\*H\*U or A = L\*L\*\*H computed by CPOTRF

## SYNOPSIS

- SUBROUTINE CPOTRS(

  UPLO, N, NRHS, A, LDA, B, LDB, INFO )

- CHARACTER

  UPLO

- INTEGER

  INFO, LDA, LDB, N, NRHS

- COMPLEX

  A( LDA, \* ), B( LDB, \* )

## PURPOSE

CPOTRS solves a system of linear equations A\*X = B with a Hermitian positive definite matrix A using the Cholesky factorization  A = U\*\*H\*U or A = L\*L\*\*H computed by CPOTRF.

## ARGUMENTS

- UPLO (input) CHARACTER\*1

  \= 'U':  Upper triangle of A is stored;\
   \= 'L':  Lower triangle of A is stored.

- N (input) INTEGER

  The order of the matrix A.  N \>= 0.

- NRHS (input) INTEGER

  The number of right hand sides, i.e., the number of columns of the matrix B.  NRHS \>= 0.

- A (input) COMPLEX array, dimension (LDA,N)

  The triangular factor U or L from the Cholesky factorization A = U\*\*H\*U or A = L\*L\*\*H, as computed by CPOTRF.

- LDA (input) INTEGER

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

- B (input/output) COMPLEX array, dimension (LDB,NRHS)

  On entry, the right hand side matrix B. On exit, the solution matrix X.

- LDB (input) INTEGER

  The leading dimension of the array B.  LDB \>= max(1,N).

- INFO (output) INTEGER

  \= 0:  successful exit\
   \< 0:  if INFO = -i, the i-th argument had an illegal value