naginterfaces.library.blas.dzasum

naginterfaces.library.blas.dzasum(x)

dzasum returns the sum of the absolute values of the real and imaginary parts of the elements in a complex vector.

For full information please refer to the NAG Library document for f06jk

https://support.nag.com/numeric/nl/nagdoc_30.3/flhtml/f06/f06jkf.html

Parameters

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

The $n$-element vector $x$.

Returns

sumxfloat

The sum of the absolute values of the real and imaginary parts of the elements in the complex vector, $x$.

Raises

NagValueError

(errno $3$)

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

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

Notes

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

dzasum returns the norm

$$\left|Re\left(x_1\right)\right|+\left|Im\left(x_1\right)\right|+\cdots +\left|Re\left(x_n\right)\right|+\left|Im\left(x_n\right)\right|$$

of the $n$-element complex vector $x$.

References

Lawson, C L, Hanson, R J, Kincaid, D R and Krogh, F T, 1979, Basic linear algebra supbrograms for Fortran usage, ACM Trans. Math. Software (5), 308–325