get-proportions

[AM]

;;; GETTING THE LENGTH-PROPORTIONS AS INTEGERS

(defun get-proportions (omn_seq &key (abs 'nil))
  (let ((denoms))
    (progn 
      (setf denoms (remove-duplicates
                    (loop for i in (omn :length omn_seq)
                      collect (denominator (abs i)))))
      (loop for i in (omn :length omn_seq)
        collect (if (equal abs 't)
                  (* (abs i) (apply 'lcm denoms))
                  (* i (apply 'lcm denoms)))))))

;; examples      
(get-proportions '(-3q 3h_h. d3 mf))
(get-proportions '(5q 5q 5q 5q 5q -e -s t t -q))
(get-proportions '(5q 5q 5q 5q 5q -e -s t t -q) :abs t)
(get-proportions '(-e -t t t t t t t t t -s. -q))


;;; HOW TO USE

(setf rhy '(-3h 3q_5h. 5q 5q c4))
(setf props (get-proportions rhy :abs nil))


;;; you can use that for GEN-LENGTH-CONSTANT

;; ordinary
(gen-length-constant props 'w.)
;; a bit advanced
(gen-length-constant props 'h.)
;; crazy 
(gen-length-constant props 'h._e)

 

[opmo]

With nested lists:

(defun get-proportions (sequence &key abs)
  (do-verbose ("get-proportions")
    (flet ((get-proportions-l (sequence &key abs)
             (let* ((length (omn-length sequence))
                    (den (remove-duplicates
                          (loop for i in length
                            collect (denominator (abs i)))
                          :from-end t)))
               (loop for i in length
                 collect (if abs (* (abs i) (apply #'lcm den))
                           (* i (apply #'lcm den)))))))
      (if (listsp sequence)
        (loop for i in sequence
          collect (get-proportions-l i :abs abs))
        (get-proportions-l sequence :abs abs)))))
    
(get-proportions '(5q 5q 5q 5q 5q -e -s t t -q))
=> (8 8 8 8 8 -20 -10 5 5 -40)

(get-proportions '((-e -t t t t) (t t t t t -s. -q)))
=> ((-4 -1 1 1 1) (1 1 1 1 1 -3 -8))