(define (make-single-bytevector . elements)
  (define len (length elements))
  (define bv (make-bytevector (* len 4)))
  (let loop ([i 0]
             [elem elements])
    (if (= len i)
        bv
        (begin
          (bytevector-ieee-single-set! bv (* i 4) (car elem) 'little)
          (loop (+ 1 i) (cdr elem))))))

(define (make-double-bytevector . elements)
  (define len (length elements))
  (define bv (make-bytevector (* len 8)))
  (let loop ([i 0]
             [elem elements])
    (if (= len i)
        bv
        (begin
          (bytevector-ieee-double-set! bv (* i 8) (car elem) 'little)
          (loop (+ 1 i) (cdr elem))))))