F06QHF (PDF version)
F06 Chapter Contents
F06 Chapter Introduction
NAG Library Manual

NAG Library Routine Document

F06QHF

Note:  before using this routine, please read the Users' Note for your implementation to check the interpretation of bold italicised terms and other implementation-dependent details.

+ Contents

    1  Purpose
    7  Accuracy
    9  Example

1  Purpose

F06QHF forms the real m by n rectangular or trapezoidal matrix A given by
aij = diag if i=j const if ij .

2  Specification

SUBROUTINE F06QHF ( MATRIX, M, N, CON, DIAG, A, LDA)
INTEGER  M, N, LDA
REAL (KIND=nag_wp)  CON, DIAG, A(LDA,*)
CHARACTER(1)  MATRIX

3  Description

None.

4  References

None.

5  Parameters

1:     MATRIX – CHARACTER(1)Input
On entry: the matrix type.
MATRIX='G'
General matrix.
MATRIX='U'
Upper trapezoidal matrix (upper triangular if m=n).
MATRIX='L'
Lower trapezoidal matrix (lower triangular if m=n).
Constraint: MATRIX='G', 'U' or 'L'.
2:     M – INTEGERInput
On entry: m, the number of rows of the matrix A.
Constraint: M0.
3:     N – INTEGERInput
On entry: n, the number of columns of the matrix A.
Constraint: N0.
4:     CON – REAL (KIND=nag_wp)Input
5:     DIAG – REAL (KIND=nag_wp)Input
6:     A(LDA,*) – REAL (KIND=nag_wp) arrayOutput
Note: the second dimension of the array A must be at least N.
On exit: the m by n general or trapezoidal matrix A.
  • If MATRIX='U', A is upper trapezoidal and the elements of the array below the diagonal are not referenced.
  • If MATRIX='L', A is lower trapezoidal and the elements of the array above the diagonal are not referenced.
7:     LDA – INTEGERInput
On entry: the first dimension of the array A as declared in the (sub)program from which F06QHF is called.
Constraint: LDA max1,M .

6  Error Indicators and Warnings

None.

7  Accuracy

Not applicable.

8  Further Comments

None.

9  Example

None.

F06QHF (PDF version)
F06 Chapter Contents
F06 Chapter Introduction
NAG Library Manual

© The Numerical Algorithms Group Ltd, Oxford, UK. 2011