# naginterfaces.library.blas.zaxpyi¶

naginterfaces.library.blas.zaxpyi(a, x, indx, y)[source]

zaxpyi adds a scaled sparse complex vector to an unscaled complex vector.

For full information please refer to the NAG Library document for f06gt

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06gtf.html

Parameters
acomplex

The scalar .

xcomplex, array-like, shape

The compressed vector . contains for .

indxint, array-like, shape

The indices of the elements in the compressed vector .

ycomplex, array-like, shape

The vector . Only elements corresponding to indices in are accessed.

Returns
ycomplex, ndarray, shape

The updated vector .

Raises
NagValueError
(errno )

On entry, error in parameter .

Constraint: the indices must be distinct.

Notes

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

zaxpyi performs the operation

where is a sparse complex vector stored in compressed form, and is a complex vector in full storage form.

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