naginterfaces.library.blas.drot

naginterfaces.library.blas.drot(x, y, c, s)

drot applies a real plane rotation to two real vectors.

For full information please refer to the NAG Library document for f06ep

https://www.nag.com/numeric/nl/nagdoc_29.3/flhtml/f06/f06epf.html

Parameters

xfloat, array-like, shape $\left(n\right)$

The $n$-element vector $x$.

yfloat, array-like, shape $\left(n\right)$

The $n$-element vector $y$.

cfloat

The value $c$, the cosine of the rotation.

sfloat

The value $s$, the sine of the rotation.

Returns

xfloat, ndarray, shape $\left(n\right)$

The transformed vector $x$.

yfloat, ndarray, shape $\left(n\right)$

The transformed vector $y$.

Notes

No equivalent traditional C interface for this routine exists in the NAG Library.

drot applies a real plane rotation to two $n$-element real vectors $x$ and $y$:

$$\begin{array}{c}\left(\begin{array}{c}{x}^T\\ y^T\end{array}\right)\leftarrow \left(\begin{array}{cc}c& s\\ -s& c\end{array}\right)\left(\begin{array}{c}{x}^T\\ y^T\end{array}\right)\text{.}\end{array}$$

The plane rotation has the form generated by drotg() or drotgc().

References

Lawson, C L, Hanson, R J, Kincaid, D R and Krogh, F T, 1979, Basic linear algebra supbrograms for Fortran usage, ACM Trans. Math. Software (5), 308–325