Is there a simple way to repeat a list until it is the length of another list? 

 

Basically do the same thing that make-omn does but for other parameters. 

 

For example if I have a list of numbers '(4 3 2) and pitches '(a4 b4 c4 d4 e4), I would like to repeat the numbers until there are exactly the same number of elements in each list. 

 

Thanks!

span is your friend 🙂

 

(setf num '(4 3 2)) 
 (setf pitch '(a4 b4 c4 d4 e4))

(span pitch num)
==>(4 3 2 4 3)

 

Great! Thank you!!

 

So can you help me with this function? I basically want all three elements to be spanned into the longest of the three. How would you suggest I do this?

 

(defun pattern-maker (chords durations repetitions)
(loop 
  :for i in chords
  :for j in durations
  :for k in repetitions
  :collect (make-omn 
            :length (gen-repeat k j)
            :pitch (gen-repeat k i))))

 

Thanks!

Imagery function 🙂 with the output (what you are looking for) otherwise not possible to help.

Ok - 

 

So as a simple example - 

 

(setf chords '(c4e4g4 e4g4c5))

(setf durations '(q e q e s))
                   
(setf repetitions '(7 1 6 2 5 3 4 4))
                   
(length (span  chords repetitions))

(defun pattern-maker (chords durations repetitions)
(loop 
  :for i in chords
  :for j in durations
  :for k in repetitions
  :collect (make-omn 
            :length (gen-repeat k j)
            :pitch (gen-repeat k i))))

 

Would give the following 

 

 

I got this by running: 

 

(pattern-maker (span  repetitions chords) 
               (span  repetitions durations)
               repetitions)

 

Which is fine - but if "repetitions" was shorter than "chords" I would need to span everything to chords. 

 

So I guess I need a condition and define a variable that chooses the largest list of the three and span onto that list. I don't know how to do that 🙂

 

Many thanks!

 

(setf num '(4 3 2 2 3 4 5)) 
(setf pitch '(a4 b4 c4 d4 e4))

(if (< (length num) (length pitch)) pitch num) 
=>(4 3 2 2 3 4 5)
;;;;;;
(setf num '(4 3 2)) 
(setf pitch '(a4 b4 c4 d4 e4))

(if (< (length num) (length pitch)) pitch num) 
=>(a4 b4 c4 d4 e4)

hth

 

Edit: I think you need cond to compare the length of three lists with each other:

(setf durations '(q e q e s))

(setf chords '(c4e4g4 e4g4c5)) 

(setf repetitions '(7 1 6 2 5 3 4 4))

(cond ((> (length chords) (and (length durations) (length repetitions))) chords)
      ((> (length durations) (and (length chords) (length repetitions))) durations)
      ((> (length repetitions) (and (length chords) (length durations))) repetitions))

 

Yes - that last condition is exactly what I was looking for! My lisp chops are not that great....

 

How would you incorporate this condition into the main function 'pattern-maker'? 

 

Many thanks!

This seems to work - let me know if there's a more elegant way to do this

 

(defun pattern-maker (chords durations repetitions)
  (let ((longest 

       (cond ((> (length chords) (and (length durations) (length repetitions))) chords)
      ((> (length durations) (and (length chords) (length repetitions))) durations)
      ((> (length repetitions) (and (length chords) (length durations))) repetitions))

))
  (loop 
  :for i in (span  longest chords)
  :for j in (span  longest durations)
  :for k in (span  longest repetitions) 
  :collect (make-omn 
            :length (gen-repeat k j)
            :pitch (gen-repeat k i)))))
 

Another possible way:

 

(setf chords '(c4e4g4 e4g4c5))
(setf durations '(q e q e s))
                   
(setf repetitions '(7 1 6 2 5 3 4 4))

(setf out (gen-repeat
           repetitions
           (make-omn
            :pitch (mclist chords)
            :length (gen-trim 
                     (length repetitions) 
                     (mclist durations))
            )))

S.