NAG FL Interface
f06bef (drotj)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{job}$ – Character(1) Input

On entry: specifies the property which determines the precise form of the rotation.

$\mathbf{job}=\text{'B'}$

$c\ge 1/\sqrt{2}$.

$\mathbf{job}=\text{'S'}$

$0\le c\le 1/\sqrt{2}$.

$\mathbf{job}=\text{'M'}$

$\left|a\right|\ge \left|b\right|$.

Constraint: $\mathbf{job}=\text{'B'}$, $\text{'S'}$ or $\text{'M'}$.

2: $\mathbf{x}$ – Real (Kind=nag_wp) Input/Output

On entry: the value $x$, the $(1,1)$ element of the input matrix.

On exit: the value $a$.

3: $\mathbf{y}$ – Real (Kind=nag_wp) Input/Output

On entry: the value $y$, the $(1,2)$ or $(2,1)$ element of the input matrix.

On exit: the value $t$, the tangent of the rotation.

4: $\mathbf{z}$ – Real (Kind=nag_wp) Input/Output

On entry: the value $z$. the $(2,2)$ element of the input matrix.

On exit: the value $b$.

5: $\mathbf{c}$ – Real (Kind=nag_wp) Output

On exit: the value $c$, the cosine of the rotation.

6: $\mathbf{s}$ – Real (Kind=nag_wp) Output

On exit: the value $s$, the sine of the rotation.

6 Error Indicators and Warnings

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example