naginterfaces.library.blast.isum

naginterfaces.library.blast.isum(x)

isum sums the elements of an integer vector.

For full information please refer to the NAG Library document for f16dl

https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/f16/f16dlf.html

Parameters

xint, array-like, shape $\left(n\right)$

The $n$-element vector $x$.

If $\text{incx}<0$, $x_{\text{i}}$ must be stored in $x[(n-\text{i})\times \left|\text{incx}\right|]$, for $\text{i}=1,2,\dots ,n$.

If $n=0$, $x$ is not referenced.

Returns

sumxint

The sum of the elements of $x$.

Raises

NagValueError

(errno $-3$)

On entry, error in parameter $\text{incx}$.

Constraint: $\text{incx}\ne 0$.

Notes

isum returns the sum

$$x_1+x_2+\cdots +x_n$$

of the elements of an $n$-element integer vector $x$.

If $n\le 0$ on entry, isum immediately returns the value $0$.

References

Basic Linear Algebra Subprograms Technical (BLAST) Forum, 2001, Basic Linear Algebra Subprograms Technical (BLAST) Forum Standard, University of Tennessee, Knoxville, Tennessee, https://www.netlib.org/blas/blast-forum/blas-report.pdf