# naginterfaces.library.blas.droti¶

naginterfaces.library.blas.droti(x, indx, y, c, s)[source]

droti applies a real plane rotation to a sparse real vector and a real vector.

For full information please refer to the NAG Library document for f06ex

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06exf.html

Parameters
xfloat, array-like, shape

The nonzero elements of the sparse vector .

indxint, array-like, shape

must contain the index of in the sparse vector , for .

yfloat, array-like, shape

The vector . Only the elements corresponding to indices in are referenced.

cfloat

The value , the cosine of the rotation.

sfloat

The value , the sine of the rotation.

Returns
xfloat, ndarray, shape

The transformed vector .

yfloat, ndarray, shape

The transformed vector . Only elements corresponding to indices in are altered.

Notes

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

droti applies a real plane rotation to a sparse real vector stored in compressed form and a real vector in full storage form:

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

References

Dodson, D S, Grimes, R G and Lewis, J G, 1991, Sparse extensions to the Fortran basic linear algebra subprograms, ACM Trans. Math. Software (17), 253–263