---
name: "dsyconv.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/dsyconv.f"
---

# dsyconv.f(3)

## NAME

SRC/dsyconv.f

## SYNOPSIS

### Functions/Subroutines

subroutine **dsyconv** (uplo, way, n, a, lda, ipiv, e, info)\
 **DSYCONV**

## Function/Subroutine Documentation

### subroutine dsyconv (character uplo, character way, integer n, double precision, dimension( lda, \* ) a, integer lda, integer, dimension( \* ) ipiv, double precision, dimension( \* ) e, integer info)

**DSYCONV**

**Purpose:**

```
!>
!> DSYCONV convert A given by TRF into L and D and vice-versa.
!> Get Non-diag elements of D (returned in workspace) and
!> apply or reverse permutation done in TRF.
!>
```

**Parameters**

*UPLO*

```
!>          UPLO is CHARACTER*1
!>          Specifies whether the details of the factorization are stored
!>          as an upper or lower triangular matrix.
!>          = 'U':  Upper triangular, form is A = U*D*U**T;
!>          = 'L':  Lower triangular, form is A = L*D*L**T.
!>
```

*WAY*

```
!>          WAY is CHARACTER*1
!>          = 'C': Convert
!>          = 'R': Revert
!>
```

*N*

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

*A*

```
!>          A is DOUBLE PRECISION array, dimension (LDA,N)
!>          The block diagonal matrix D and the multipliers used to
!>          obtain the factor U or L as computed by DSYTRF.
!>
```

*LDA*

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

*IPIV*

```
!>          IPIV is INTEGER array, dimension (N)
!>          Details of the interchanges and the block structure of D
!>          as determined by DSYTRF.
!>
```

*E*

```
!>          E is DOUBLE PRECISION array, dimension (N)
!>          E stores the supdiagonal/subdiagonal of the symmetric 1-by-1
!>          or 2-by-2 block diagonal matrix D in LDLT.
!>
```

*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 **113** of file **dsyconv.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.