I am working with a score in Lilypond that has a lot of repetitions, where basically every bar has to be repeated a certain number of times. I would like to be able to write above every bar the number of times it should be repeat, similar to the score below (which was not created in Lilypond):
It would be great to be able to have some brackets above the bar and also to have the "3x" centralized, just like in the example above. So far, the only (temporary) solution I was able to come up with in Lilypond was to add repeat bars and then simply write "3x" above the first note of every bar (since I could not have it centralized on the bar either). It does not look very good, but gets the job done. This temporary solution looks like this:
Any suggestions of how to make this example look more similar to the first inn Lilypond would be extremely welcome!
This is a workaround for this problem:
\version "2.19.15"
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% COPY ALL THIS BELOW %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% repeatBracket snippet
% will add .----Nx----. above a bar, where N is the number of repetitions
% based on the wonderful spanner by David Nalesnik (see: http://lists.gnu.org/archive/html/lilypond-user/2014-10/msg00446.html )
#(define (test-stencil grob text)
(let* ((orig (ly:grob-original grob))
(siblings (ly:spanner-broken-into orig)) ; have we been split?
(refp (ly:grob-system grob))
(left-bound (ly:spanner-bound grob LEFT))
(right-bound (ly:spanner-bound grob RIGHT))
(elts-L (ly:grob-array->list (ly:grob-object left-bound 'elements)))
(elts-R (ly:grob-array->list (ly:grob-object right-bound 'elements)))
(break-alignment-L
(filter
(lambda (elt) (grob::has-interface elt 'break-alignment-interface))
elts-L))
(break-alignment-R
(filter
(lambda (elt) (grob::has-interface elt 'break-alignment-interface))
elts-R))
(break-alignment-L-ext (ly:grob-extent (car break-alignment-L) refp X))
(break-alignment-R-ext (ly:grob-extent (car break-alignment-R) refp X))
(num
(markup text))
(num
(if (or (null? siblings)
(eq? grob (car siblings)))
num
(make-parenthesize-markup num)))
(num (grob-interpret-markup grob num))
(num-stil-ext-X (ly:stencil-extent num X))
(num-stil-ext-Y (ly:stencil-extent num Y))
(num (ly:stencil-aligned-to num X CENTER))
(num
(ly:stencil-translate-axis
num
(+ (interval-length break-alignment-L-ext)
(* 0.5
(- (car break-alignment-R-ext)
(cdr break-alignment-L-ext))))
X))
(bracket-L
(markup
#:path
0.1 ; line-thickness
`((moveto 0.5 ,(* 0.5 (interval-length num-stil-ext-Y)))
(lineto ,(* 0.5
(- (car break-alignment-R-ext)
(cdr break-alignment-L-ext)
(interval-length num-stil-ext-X)))
,(* 0.5 (interval-length num-stil-ext-Y)))
(closepath)
(rlineto 0.0
,(if (or (null? siblings) (eq? grob (car siblings)))
-1.0 0.0)))))
(bracket-R
(markup
#:path
0.1
`((moveto ,(* 0.5
(- (car break-alignment-R-ext)
(cdr break-alignment-L-ext)
(interval-length num-stil-ext-X)))
,(* 0.5 (interval-length num-stil-ext-Y)))
(lineto 0.5
,(* 0.5 (interval-length num-stil-ext-Y)))
(closepath)
(rlineto 0.0
,(if (or (null? siblings) (eq? grob (last siblings)))
-1.0 0.0)))))
(bracket-L (grob-interpret-markup grob bracket-L))
(bracket-R (grob-interpret-markup grob bracket-R))
(num (ly:stencil-combine-at-edge num X LEFT bracket-L 0.4))
(num (ly:stencil-combine-at-edge num X RIGHT bracket-R 0.4)))
num))
#(define-public (Measure_attached_spanner_engraver context)
(let ((span '())
(finished '())
(event-start '())
(event-stop '()))
(make-engraver
(listeners ((measure-counter-event engraver event)
(if (= START (ly:event-property event 'span-direction))
(set! event-start event)
(set! event-stop event))))
((process-music trans)
(if (ly:stream-event? event-stop)
(if (null? span)
(ly:warning "You're trying to end a measure-attached spanner but you haven't started one.")
(begin (set! finished span)
(ly:engraver-announce-end-grob trans finished event-start)
(set! span '())
(set! event-stop '()))))
(if (ly:stream-event? event-start)
(begin (set! span (ly:engraver-make-grob trans 'MeasureCounter event-start))
(set! event-start '()))))
((stop-translation-timestep trans)
(if (and (ly:spanner? span)
(null? (ly:spanner-bound span LEFT))
(moment<=? (ly:context-property context 'measurePosition) ZERO-MOMENT))
(ly:spanner-set-bound! span LEFT
(ly:context-property context 'currentCommandColumn)))
(if (and (ly:spanner? finished)
(moment<=? (ly:context-property context 'measurePosition) ZERO-MOMENT))
(begin
(if (null? (ly:spanner-bound finished RIGHT))
(ly:spanner-set-bound! finished RIGHT
(ly:context-property context 'currentCommandColumn)))
(set! finished '())
(set! event-start '())
(set! event-stop '()))))
((finalize trans)
(if (ly:spanner? finished)
(begin
(if (null? (ly:spanner-bound finished RIGHT))
(set! (ly:spanner-bound finished RIGHT)
(ly:context-property context 'currentCommandColumn)))
(set! finished '())))
(if (ly:spanner? span)
(begin
(ly:warning "I think there's a dangling measure-attached spanner :-(")
(ly:grob-suicide! span)
(set! span '())))))))
\layout {
\context {
\Staff
\consists #Measure_attached_spanner_engraver
\override MeasureCounter.font-encoding = #'latin1
\override MeasureCounter.font-size = 0
\override MeasureCounter.outside-staff-padding = 2
\override MeasureCounter.outside-staff-horizontal-padding = #0
}
}
repeatBracket = #(define-music-function
(parser location N note)
(number? ly:music?)
#{
\override Staff.MeasureCounter.stencil =
#(lambda (grob) (test-stencil grob #{ #(string-append(number->string N) "×") #} ))
\startMeasureCount
\repeat volta #N { $note }
\stopMeasureCount
#}
)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% ...UNTIL HERE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
{
\repeatBracket 7 {c'1}
\repeatBracket 32 {d' g}
\repeatBracket 14 {e' f g}
\repeatBracket 29 {f' a bes \break cis' e''}
\repeatBracket 1048 {g'1}
}
This code above gives the following result:
]
This solution was not created by myself, but sent to me by David Nalesnik, from lilypond-user mailing list. I just would like to share it here in case someone would need it as well. I've made just some very minor adjustments to what David sent me.
I just had a similar problem but preferred the style on your second example, with the 3x above the bar. The solution I found was:
f e d c |
\mark \markup {"3x"}\repeat volta 3 {c d e f}
f e d c |
generating
Maybe someone else has a use for it.
Related
I need to iterate through a list with sublists in Racket using list iteration and filtering, one of the lists is a nested list, I tried using "list?" and "car" to iterate inside but of course that would only apply to the first value of the sublist.
Is there a way to iterate through the whole nested list using list iteration and filtering?
(define (count-evens lst)
(length
(filter
(lambda (x)
(cond
[(and (list? x)
(and (number? (car x))
(eq? (modulo (car x) 2) 0)))
#t]
[(and (number? x)
(eq? (modulo x 2) 0))
#t]
[else
#f]))
lst)))
(count-evens '(1 2 5 4 (8 4 (b (10 3 3))) 3))
=> 3
Should return => 5
I would use a recursive function to do this but the assignment doesn't allow it.
"...assignment doesn't allow [recursive functions]"
Not sure what is allowed for this assignment, but
in ye olden days we processed recursive data structures with stacks...
(define (count-evens lst)
(define (lst-at stack) ;; (car stack) = index in deepest sub-list
;; produce list cursor within lst indexed by stack
(do ([stack (reverse stack) (cdr stack)]
[cursor (list lst) (list-tail (car cursor) (car stack))])
((null? stack) cursor)))
(do ([stack (list 0)
(cond
[(null? (lst-at stack))
(cdr stack)] ;; pop stack
[(pair? (car (lst-at stack)))
(cons 0 stack)] ;; push stack
[else ;; step through current (sub)list
(cons (+ 1 (car stack)) (cdr stack))])]
[count 0
(let ([item (car (lst-at stack))])
(if (and (number? item) (even? item)) (+ 1 count) count))])
((null? (lst-at stack)) count)))
> (count-evens '(1 2 5 4 (8 4 (b (10 3 3))) 3)) ;=>
5
Following SICP's instruction, I rewrite its intersection-set as:
(defun intersection-set (set1 set2)
(cond ((or (null set1) (null set2)) '())
((element-of-setp (car set1) set2)
(cons (car set1)
(intersection-set (cdr set1) set2)))
(t (intersection-set (cdr set1) set2))))
(defun element-of-setp(x set)
(cond ((null set) false)
((equal x (car set)) t)
(t (element-of-setp x (cdr set)))))
(intersection-set (list 1 2) (list 2 3 4))
Running it reports the following error:
element-of-setp: Symbol’s value as variable is void: false
However, element-of-setp on its own seems to work properly:
#+begin_src emacs-lisp :tangle yes
(defun element-of-setp(x set)
(cond ((null set) false)
((equal x (car set)) t)
(t (element-of-setp x (cdr set)))))
(element-of-setp 1 (list 1 2 3))
#+end_src
#+RESULTS:
: t
What's the problem?
However, element-of-setp on its own seems to work properly:
Unfortunately, the test you used did not cover all the possible cases.
If you try instead:
(element-of-setp 5 (list 1 2 3))
Then the function is going to reach the case where the list is empty, and in that it will evaluate false, which is most likely undefined; as stated in the comment, boolean values in Emacs-Lisp are represented by nil and non-nil values (atoms).
I've got some function func and want to apply it on a list lst, so I used map but I need to have the first and last element of the list evaluated with some other function func2.
So basically I want this:
(map (lambda (x)
(cond [(isBeginningOfList? lst) (func2 x)]
[(isEndOfList? lst) (func2 x)]
[else (func x)]))
lst)
Obviously this doesn't work.
How can I achieve this functionality?
Can I somehow get a key of each list entry? Like lambda(key,val) and then compare (equal? key 0) / (equal? key (length lst))?
There's for/list with in-indexed and that does what you describe:
(define (f lst f1 f2)
(define last (sub1 (length lst)))
(for/list (((e i) (in-indexed lst)))
(if (< 0 i last)
(f1 e)
(f2 e))))
then
> (f '(1 2 3 4 5) sub1 add1)
'(2 1 2 3 6)
You can use a map on all the elements except the first and the last one and treat those two separately. In this way you avoid those comparisons which you would do for every element.
(define special-map
(λ (lst f1 f2)
(append (list (f1 (car lst)))
(map f2 (drop-right (cdr lst) 1))
(list (f1 (last lst))))))
Example
Let's try to increment the first and the last elements and decrement all the others.
> (special-map '(1 2 3 4 5) add1 sub1)
'(2 1 2 3 6)
Later edit
I changed (take (cdr lst) (- (length lst) 2)) with (drop-right (cdr lst) 1).
I'm new to Clojure. I was wondering how I could optimize an algorithm to count the number of inversions in a list. From what I understand, Clojure doesn't do tail call optimization unless specifically asked to? How do you get it to do this?
This first attempt with a mutated variable has a runtime of about 3.5s. But my second attempt was a functional version and it takes about 1m15s! and both require growing the stack size quite a bit (like -Xss12m).
How would I go about getting better performance?
I'd prefer to not have mutable variables (like the functional one) if possible. You can create the array file by typing something like seq 100000 | sort -R > IntArray.txt.
The first attempt w/ mutable variable:
(use 'clojure.java.io)
(def inversions 0)
(defn merge_and_count' [left right left_len]
(if (empty? right) left
(if (empty? left) right
(if (<= (first left) (first right))
(cons (first left) (merge_and_count' (rest left) right (- left_len 1)))
(let [_ (def inversions (+ inversions left_len))]
(cons (first right) (merge_and_count' left (rest right) left_len)))
))))
(defn inversion_count [list]
(if (or (empty? list) (nil? (next list))) list
(let [mid (quot (count list) 2)]
(merge_and_count' (inversion_count (take mid list))
(inversion_count (drop mid list)) mid)
)))
(defn parse-int [s]
(Integer. (re-find #"\d+" s )))
(defn get-lines [fname]
(with-open [r (reader fname)]
(doall (map parse-int (line-seq r)))))
(let [list (get-lines "IntArray.txt")
_ (inversion_count list)]
(print inversions))
My second attempt to be purely functional (no mutability):
(use 'clojure.java.io)
(defn merge_and_count' [left right inversions]
(if (empty? right) (list left inversions)
(if (empty? left) (list right inversions)
(if (<= (first left) (first right))
(let [result (merge_and_count' (rest left) right inversions)]
(list (cons (first left) (first result)) (second result)))
(let [result (merge_and_count' left (rest right) (+ inversions (count left)))]
(list (cons (first right) (first result)) (second result)))
))))
(defn inversion_count [list' list_len]
(if (or (empty? list') (nil? (next list'))) (list list' 0)
(let [mid (quot list_len 2)
left (inversion_count (take mid list') mid)
right (inversion_count (drop mid list') (- list_len mid))]
(merge_and_count' (first left) (first right) (+ (second left) (second right)))
)))
(defn parse-int [s]
(Integer. (re-find #"\d+" s )))
(defn get-lines [fname]
(with-open [r (reader fname)]
(doall (map parse-int (line-seq r)))))
(let [list (get-lines "IntArray.txt")
result (inversion_count list 100000)]
(print (second result)))
The stack overflows due to the recursion in merge-and-count. I tried this approach, and for 100000 items, it came back instantly.
(defn merge_and_count [left right inversions]
(loop [l left r right inv inversions result []]
(cond (and (empty? r) (empty? l)) [result inv]
(empty? r) [(apply conj result l) inv]
(empty? l) [(apply conj result r) inv]
(<= (first l) (first r)) (recur (rest l) r inv (conj result (first l)))
:else (recur l (rest r) (+ inv (count l)) (conj result (first r))))))
You need to replace this code with code from your second approach.
i am new to racket. i am trying create a list from the input of the user and when the value 0 is entred the first three elements are printed.
here is the code:
#lang racket
(define lst '())
(define (add)
(define n(read))
(if (= n 0)
;then
(
list (car lst) (cadr lst) (caddr lst)
)
;else
(
(set! lst (append lst (list n)))
(add)
)
)
)
(add)
i tested the program with the values 1 2 3 4 5 0
but i keep getting this error:
application: not a procedure;
expected a procedure that can be applied to arguments
given: #<void>
arguments...:
'(1 2 3)
can anyone help me figure out what's wrong.
If you have more than one expression in the "then" or "else" parts, you must enclose them inside a begin, because a pair of () in Scheme are used for function application - that explains the error you're getting. Try this:
(define (add)
(define n (read))
(if (= n 0)
; then
(list (car lst) (cadr lst) (caddr lst))
; else
(begin
(set! lst (append lst (list n)))
(add))))
I had a similar problem, in a function i called a parameter with the same name of a structure, so, trying to create an instance of that structure i got the same error.
example:
> (struct example (param1 param2) #:transparent)
> (define e (example 1 2))
> e
(example 1 2)
> (define (fn e)
(example (example-param1 e) 0))
> (fn e)
(example 1 0)
> (define (fn example)
(example (example-param1 example) 0))
> (fn e)
application: not a procedure;
expected a procedure that can be applied to arguments
given: (example 1 2)
arguments...:
I hope this helps
Your code have a few problems, for example it will fail if you enter less than 3 elements. Also, it is not considered good style to define variables at the module level.
I'd suggest the following:
(define (add)
(define (sub cnt lst)
(define n (read))
(if (= n 0)
(reverse lst)
(if (< cnt 3)
(sub (add1 cnt) (cons n lst))
(sub cnt lst))))
(sub 0 '()))