naginterfaces.library.blas.dgthrz¶
- naginterfaces.library.blas.dgthrz(y, indx)[source]¶
dgthrz
gathers specified (usually nonzero) elements of a real vector in full storage form into a sparse real vector in compressed form. The specified elements of are set to zero.For full information please refer to the NAG Library document for f06ev
https://support.nag.com/numeric/nl/nagdoc_30.3/flhtml/f06/f06evf.html
- Parameters
- yfloat, array-like, shape
The vector . Only elements corresponding to indices in are accessed.
- indxint, array-like, shape
must contain the index , for , which is to be gathered into .
- Returns
- yfloat, ndarray, shape
The elements of corresponding to indices in are set to zero.
- xfloat, ndarray, shape
The compressed 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.
dgthrz
gathers the specified elements of a vector, , in full storage form, into the equivalent sparse vector compressed form. The gathered elements of are set to zero.
- 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