function zsum( N, x, strideX ) {
	return ndarray( N, x, strideX, stride2offset( N, strideX ) );
}
Computes the sum of double-precision complex floating-point strided array elements.

@param {PositiveInteger} N - number of indexed elements
@param {Complex128Array} x - input array
@param {integer} strideX - stride length
@returns {Complex128} sum

@example
var Complex128Array = require( '@stdlib/array/complex128' );

var x = new Complex128Array( [ 1.0, -2.0, 2.0, 3.0 ] );

var v = zsum( x.length, x, 1 );
// returns <Complex128>[ 3.0, 1.0 ]