code: func funcScalar(vals []Value, args Expressions, enh *EvalNodeHelper) Vector {
  	v := vals[0].(Vector)
  	if len(v) != 1 {
  		return append(enh.out, Sample{
  			Point: Point{V: math.NaN()},
  		})
  	}
  	return append(enh.out, Sample{
  		Point: Point{V: v[0].V},
  	})
  }
docs: // === Scalar(node ValueTypeVector) Scalar ===