nag_ztr_copy (f16tec) (PDF version)
f16 Chapter Contents
f16 Chapter Introduction
NAG C Library Manual

NAG Library Function Document

nag_ztr_copy (f16tec)

+ Contents

    1  Purpose
    7  Accuracy

1  Purpose

nag_ztr_copy (f16tec) copies a complex triangular matrix.

2  Specification

#include <nag.h>
#include <nagf16.h>
void  nag_ztr_copy (Nag_OrderType order, Nag_UploType uplo, Nag_TransType trans, Nag_DiagType diag, Integer n, const Complex a[], Integer pda, Complex b[], Integer pdb, NagError *fail)

3  Description

nag_ztr_copy (f16tec) performs the triangular matrix copy operations
BA,   BAT  or   BAH
where A and B are n by n complex triangular matrices.

4  References

The BLAS Technical Forum Standard (2001) http://www.netlib.org/blas/blast-forum

5  Arguments

1:     orderNag_OrderTypeInput
On entry: the order argument specifies the two-dimensional storage scheme being used, i.e., row-major ordering or column-major ordering. C language defined storage is specified by order=Nag_RowMajor. See Section 3.2.1.3 in the Essential Introduction for a more detailed explanation of the use of this argument.
Constraint: order=Nag_RowMajor or Nag_ColMajor.
2:     uploNag_UploTypeInput
On entry: specifies whether the upper or lower triangular part of A is stored.
uplo=Nag_Upper
The upper triangular part of A is stored.
uplo=Nag_Lower
The lower triangular part of A is stored.
Constraint: uplo=Nag_Upper or Nag_Lower.
3:     transNag_TransTypeInput
On entry: specifies the operation to be performed.
trans=Nag_NoTrans
BA.
trans=Nag_Trans
BAT.
trans=Nag_ConjTrans
BAH.
Constraint: trans=Nag_NoTrans, Nag_Trans or Nag_ConjTrans.
4:     diagNag_DiagTypeInput
On entry: specifies whether A has nonunit or unit diagonal elements.
diag=Nag_NonUnitDiag
The diagonal elements are stored explicitly.
diag=Nag_UnitDiag
The diagonal elements are assumed to be 1 and are not referenced.
Constraint: diag=Nag_NonUnitDiag or Nag_UnitDiag.
5:     nIntegerInput
On entry: n, the order of the matrices A and B.
Constraint: n0.
6:     a[dim]const ComplexInput
Note: the dimension, dim, of the array a must be at least max1,pda×n.
On entry: the n by n triangular matrix A.
If order=Nag_ColMajor, Aij is stored in a[j-1×pda+i-1].
If order=Nag_RowMajor, Aij is stored in a[i-1×pda+j-1].
If uplo=Nag_Upper, the upper triangular part of A must be stored and the elements of the array below the diagonal are not referenced.
If uplo=Nag_Lower, the lower triangular part of A must be stored and the elements of the array above the diagonal are not referenced.
If diag=Nag_UnitDiag, the diagonal elements of A are assumed to be 1, and are not referenced.
7:     pdaIntegerInput
On entry: the stride separating row or column elements (depending on the value of order) of the matrix A in the array a.
Constraint: pdamax1,n.
8:     b[dim]ComplexOutput
Note: the dimension, dim, of the array b must be at least max1,pdb×n.
On exit: the n by n triangular matrix B.
If order=Nag_ColMajor, Bij is stored in b[j-1×pdb+i-1].
If order=Nag_RowMajor, Bij is stored in b[i-1×pdb+j-1].
If uplo=Nag_Upper and trans=Nag_NoTrans or if uplo=Nag_Lower and trans=Nag_Trans or trans=Nag_ConjTrans, B is upper triangular and the elements of the array below the diagonal are not set.
If uplo=Nag_Lower and trans=Nag_NoTrans or if uplo=Nag_Upper and trans=Nag_Trans or trans=Nag_ConjTrans, B is lower triangular and the elements of the array above the diagonal are not set.
9:     pdbIntegerInput
On entry: the stride separating row or column elements (depending on the value of order) in the array b.
Constraint: pdbmax1,n.
10:   failNagError *Input/Output
The NAG error argument (see Section 3.6 in the Essential Introduction).

6  Error Indicators and Warnings

NE_ALLOC_FAIL
Dynamic memory allocation failed.
NE_BAD_PARAM
On entry, argument value had an illegal value.
NE_INT
On entry, n=value.
Constraint: n0.
NE_INT_2
On entry, pda=value, n=value.
Constraint: pdamax1,n.
On entry, pdb=value, n=value.
Constraint: pdbmax1,n.

7  Accuracy

The BLAS standard requires accurate implementations which avoid unnecessary over/underflow (see Section 2.7 of The BLAS Technical Forum Standard (2001)).

8  Further Comments

None.

9  Example

Initializes a 4 by 4 lower triangular matrix A and copies its conjugate transpose to the upper triangular part of B.

9.1  Program Text

Program Text (f16tece.c)

9.2  Program Data

Program Data (f16tece.d)

9.3  Program Results

Program Results (f16tece.r)


nag_ztr_copy (f16tec) (PDF version)
f16 Chapter Contents
f16 Chapter Introduction
NAG C Library Manual

© The Numerical Algorithms Group Ltd, Oxford, UK. 2012