# naginterfaces.library.blas.zgthr¶

naginterfaces.library.blas.zgthr(y, indx)[source]

zgthr gathers specified (usually nonzero) elements of a complex vector in full storage form into a sparse complex vector in compressed form.

For full information please refer to the NAG Library document for f06gu

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06guf.html

Parameters
ycomplex, array-like, shape

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

indxint, array-like, shape

must contain the set of indices .

Returns
xcomplex, ndarray, shape

The compressed vector .

Notes

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

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