function createBenchmark( len ) {
	var x = uniform( len, -100.0, 100.0, options );
	return benchmark;

	function benchmark( b ) {
		var y;
		var i;

		b.tic();
		for ( i = 0; i < b.iterations; i++ ) {
			y = dscal( x.length, 1.01, x, 1 );
			if ( isnan( y[ i%x.length ] ) ) {
				b.fail( 'should not return NaN' );
			}
		}
		b.toc();
		if ( isnan( y[ i%x.length ] ) ) {
			b.fail( 'should not return NaN' );
		}
		b.pass( 'benchmark finished' );
		b.end();
	}
}
Create a benchmark function.

@private
@param {PositiveInteger} len - array length
@returns {Function} benchmark function