NAG FL Interface
x04cef (print_​matrix_​real_​band)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{m}$ – Integer Input

2: $\mathbf{n}$ – Integer Input

On entry: the number of rows and columns of the band matrix, respectively, to be printed.

If either m or n is less than $1$, x04cef will exit immediately after printing title; no row or column labels are printed.

3: $\mathbf{kl}$ – Integer Input

On entry: the number of subdiagonals of the band matrix $A$.

Constraint: $\mathbf{kl}\ge 0$.

4: $\mathbf{ku}$ – Integer Input

On entry: the number of superdiagonals of the band matrix $A$.

Constraint: $\mathbf{ku}\ge 0$.

5: $\mathbf{a}\left(\mathbf{lda},*\right)$ – Real (Kind=nag_wp) array Input

Note: the second dimension of the array a must be at least $\max \left(1,\min \left(\mathbf{m}+\mathbf{ku},\mathbf{n}\right)\right)$.

On entry: the band matrix to be printed.

The matrix is stored in rows $1$ to $k_l+k_u+1$, more precisely, the element $A_{ij}$ must be stored in

$$\mathbf{a}\left(k_u+1+i-j,j\right)\text{\hspace{1em} for }\max \left(1,j-k_u\right)\le i\le \min \left(m,j+k_l\right)\text{.}$$

6: $\mathbf{lda}$ – Integer Input

On entry: the first dimension of the array a as declared in the (sub)program from which x04cef is called.

Constraint: $\mathbf{lda}\ge \mathbf{kl}+\mathbf{ku}+1$.

7: $\mathbf{title}$ – Character(*) Input

On entry: a title to be printed above the matrix.

If $\mathbf{title}=\text{' '}$, no title (and no blank line) will be printed.

If title contains more than $80$ characters, the contents of title will be wrapped onto more than one line, with the break after $80$ characters.

Any trailing blank characters in title are ignored.

8: $\mathbf{ifail}$ – Integer Input/Output

On entry: ifail must be set to $0$, $-1\text{ or }1$. If you are unfamiliar with this argument you should refer to Section 4 in the Introduction to the NAG Library FL Interface for details.

For environments where it might be inappropriate to halt program execution when an error is detected, the value $-1\text{ or }1$ is recommended. If the output of error messages is undesirable, then the value $1$ is recommended. Otherwise, if you are not familiar with this argument, the recommended value is $0$. When the value $-\mathbf{1}\text{ or }\mathbf{1}$ is used it is essential to test the value of ifail on exit.

On exit: $\mathbf{ifail}=\mathbf{0}$ unless the routine detects an error or a warning has been flagged (see Section 6).

6 Error Indicators and Warnings

$\mathbf{ifail}=1$

On entry, $\mathbf{kl}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{kl}\ge 0$.

$\mathbf{ifail}=2$

On entry, $\mathbf{ku}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{ku}\ge 0$.

$\mathbf{ifail}=3$

On entry, $\mathbf{lda}<\mathbf{kl}+\mathbf{ku}+1$: $\mathbf{lda}=〈\mathit{\text{value}}〉$, $\mathbf{kl}=〈\mathit{\text{value}}〉$, $\mathbf{ku}=〈\mathit{\text{value}}〉$.

$\mathbf{ifail}=-99$

An unexpected error has been triggered by this routine. Please contact NAG.

See Section 7 in the Introduction to the NAG Library FL Interface for further information.

$\mathbf{ifail}=-399$

Your licence key may have expired or may not have been installed correctly.

See Section 8 in the Introduction to the NAG Library FL Interface for further information.

$\mathbf{ifail}=-999$

Dynamic memory allocation failed.

See Section 9 in the Introduction to the NAG Library FL Interface for further information.

7 Accuracy

8 Parallelism and Performance

9 Further Comments

NCOLS = 80
INDENT = 0
LABROW = 'I'
LABCOL = 'I'
FORM = ' '

10 Example

10.1 Program Text

10.2 Program Data

10.3 Program Results