naginterfaces.library.blas.zdotui

naginterfaces.library.blas.zdotui(x, indx, y)

zdotui computes the scalar product of an unconjugated sparse complex vector with a complex vector.

For full information please refer to the NAG Library document for f06gr

https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/f06/f06grf.html

Parameters

xcomplex, array-like, shape $\left(\text{nz}\right)$

The compressed vector $x$. $x$ contains $x_i$ for $i\in J$.

indxint, array-like, shape $\left(\text{nz}\right)$

$indx$ must contain the set of indices $J$.

ycomplex, array-like, shape $(max\left(indx\right))$

The vector $y$. Only elements corresponding to indices in $indx$ are accessed.

Returns

zducomplex

The value of the scalar product.

Notes

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

zdotui returns the value of the scalar product

$$x^{T}y$$

where $x$ is a sparse complex vector stored in compressed form, and $y$ 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