_lat2_(3) Library Functions Manual _lat2_(3)

# NAME

_lat2_ - <em>lat2</em>: triangular matrix, convert double <=> single

# SYNOPSIS

## Functions

subroutine dlat2s (uplo, n, a, lda, sa, ldsa, info)
DLAT2S converts a double-precision triangular matrix to a single-precision triangular matrix. subroutine zlat2c (uplo, n, a, lda, sa, ldsa, info)
ZLAT2C converts a double complex triangular matrix to a complex triangular matrix.

# Function Documentation

## subroutine dlat2s (character uplo, integer n, double precision, dimension( lda, * ) a, integer lda, real, dimension( ldsa, * ) sa, integer ldsa, integer info)

DLAT2S converts a double-precision triangular matrix to a single-precision triangular matrix.

Purpose:

``` DLAT2S converts a DOUBLE PRECISION triangular matrix, SA, to a SINGLE
PRECISION triangular matrix, A.
RMAX is the overflow for the SINGLE PRECISION arithmetic
DLAS2S checks that all the entries of A are between -RMAX and
RMAX. If not the conversion is aborted and a flag is raised.
This is an auxiliary routine so there is no argument checking.```

Parameters

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

N

```          N is INTEGER
The number of rows and columns of the matrix A.  N >= 0.```

A

```          A is DOUBLE PRECISION array, dimension (LDA,N)
On entry, the N-by-N triangular coefficient matrix A.```

LDA

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

SA

```          SA is REAL array, dimension (LDSA,N)
Only the UPLO part of SA is referenced.  On exit, if INFO=0,
the N-by-N coefficient matrix SA; if INFO>0, the content of
the UPLO part of SA is unspecified.```

LDSA

```          LDSA is INTEGER
The leading dimension of the array SA.  LDSA >= max(1,M).```

INFO

```          INFO is INTEGER
= 0:  successful exit.
= 1:  an entry of the matrix A is greater than the SINGLE
PRECISION overflow threshold, in this case, the content
of the UPLO part of SA in exit is unspecified.```

Author

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Definition at line 110 of file dlat2s.f.

## subroutine zlat2c (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, complex, dimension( ldsa, * ) sa, integer ldsa, integer info)

ZLAT2C converts a double complex triangular matrix to a complex triangular matrix.

Purpose:

``` ZLAT2C converts a COMPLEX*16 triangular matrix, SA, to a COMPLEX
triangular matrix, A.
RMAX is the overflow for the SINGLE PRECISION arithmetic
ZLAT2C checks that all the entries of A are between -RMAX and
RMAX. If not the conversion is aborted and a flag is raised.
This is an auxiliary routine so there is no argument checking.```

Parameters

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

N

```          N is INTEGER
The number of rows and columns of the matrix A.  N >= 0.```

A

```          A is COMPLEX*16 array, dimension (LDA,N)
On entry, the N-by-N triangular coefficient matrix A.```

LDA

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

SA

```          SA is COMPLEX array, dimension (LDSA,N)
Only the UPLO part of SA is referenced.  On exit, if INFO=0,
the N-by-N coefficient matrix SA; if INFO>0, the content of
the UPLO part of SA is unspecified.```

LDSA

```          LDSA is INTEGER
The leading dimension of the array SA.  LDSA >= max(1,M).```

INFO

```          INFO is INTEGER
= 0:  successful exit.
= 1:  an entry of the matrix A is greater than the SINGLE
PRECISION overflow threshold, in this case, the content
of the UPLO part of SA in exit is unspecified.```

Author

Univ. of Tennessee

Univ. of California Berkeley