sc/utilities [ Modules ]
NAME
utilities File: utilities.lsp Class Hierarchy: none: no classes defined Version: 1.0.0-beta2 Project: slippery chicken (algorithmic composition) Purpose: Various helper functions of a general nature. Author: Michael Edwards: m@michael-edwards.org Creation date: June 24th 2002 $$ Last modified: 17:47:02 Thu May 17 2012 BST SVN ID: $Id: utilities.lsp 1982 2012-05-24 15:35:54Z medward2 $
utilities/all-members [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Find out whether the members of the list given as the second argument are all present in the list given as the first argument.
ARGUMENTS
- A list in which the members of the second argument will be sought. - A list whose members will be sought in the first argument. OPTIONAL ARGUMENT - A comparison function.
RETURN VALUE
T or NIL.
EXAMPLE
(all-members '(1 2 3 4 5 6 7) '(1 2 3 7)) => T
SYNOPSIS
(defun all-members (list test-list &optional (test #'equal))
utilities/almost-zero [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Return T if a given decimal is within 0.000001 of 0.0.
ARGUMENTS
- A number.
OPTIONAL ARGUMENTS
- A number that is a user-specified difference for the comparison test.
RETURN VALUE
T if the number is within the tolerance difference to zero, otherwise NIL.
EXAMPLE
(almost-zero 0.0000007) => T
SYNOPSIS
(defun almost-zero (num &optional (tolerance 0.000001))
utilities/amp2db [ Methods ]
[ Top ] [ utilities ] [ Methods ]
DESCRIPTION
Convert a standard digital amplitude value (>0.0 to 1.0) to a corresponding decibel value.
ARGUMENTS
- A decimal number between >0.0 and 1.0.
RETURN VALUE
A decimal number that is a value in decibel.
EXAMPLE
(amp2db 0.3) => -10.457575
SYNOPSIS
(defmacro amp2db (amp)
utilities/amplitude-to-dynamic [ Functions ]
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DESCRIPTION
Convert a specified digital amplitude between 0.0 and 1.0 to a corresponding dynamic between niente and ffff.
ARGUMENTS
- A decimal number between 0.0 and 1.0.
OPTIONAL ARGUMENTS
- T or NIL to indicate whether to print a warning if the specified amplitude is <0.0 or >1.0. T = warn. Default = T.
RETURN VALUE
A symbol that is a dynamic level.
EXAMPLE
(amplitude-to-dynamic 0.3) => PP
SYNOPSIS
(defun amplitude-to-dynamic (amp &optional (warn t))
utilities/between [ Functions ]
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DESCRIPTION
Return a random number between two specified numbers. If the two numbers are integers, the random selection is inclusive. If they are decimal numbers, the result cannot be absolutely inclusive.
ARGUMENTS
- A first, lower, number. - A second, higher, number. NB: The first number must always be lower than the second.
OPTIONAL ARGUMENTS
- T or NIL to indicate whether the random seed should be fixed. - If fixed-random is set to T, a function must be given for <restart> to reset the seed (see below)
RETURN VALUE
An integer if both numbers are integers, or a float if one or both are decimal numbers.
EXAMPLE
;;; Using the defaults. This will produce a different result each time. (loop repeat 10 collect (between 1 100)) => (43 63 26 47 28 2 99 93 66 23) ;;; Setting fixed-random to T and using zerop to reset the random when i is 0 (loop repeat 5 collect (loop for i from 0 to 9 collect (between 1 100 t (zerop i)))) => ((93 2 38 81 43 19 70 18 44 26) (93 2 38 81 43 19 70 18 44 26) (93 2 38 81 43 19 70 18 44 26) (93 2 38 81 43 19 70 18 44 26) (93 2 38 81 43 19 70 18 44 26))
SYNOPSIS
(defun between (low high &optional fixed-random restart)
utilities/combine-into-symbol [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Combine a sequence of elements of any combination of type string, number, or symbol into a symbol.
ARGUMENTS
- A sequence of elements.
RETURN VALUE
A symbol as the primary value, with the length of that symbol as a secondary value.
EXAMPLE
(combine-into-symbol "test" 1 'a) => TEST1A, 6
SYNOPSIS
(defun combine-into-symbol (&rest params)
utilities/db2amp [ Methods ]
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DESCRIPTION
Convert a decibel value to a standard digital amplitude value (>0.0 to 1.0), whereby 0dB = 1.0.
ARGUMENTS
- A number that is a value in decibel.
RETURN VALUE
A decimal number between >0.0 and 1.0.
EXAMPLE
(db2amp -3) => 0.70794576
SYNOPSIS
(defmacro db2amp (db)
utilities/decimal-places [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DATE
19-Mar-2012
DESCRIPTION
Round the given number to the specified number of decimal places.
ARGUMENTS
- A number. - An integer that is the number of decimal places to which to round the given number.
RETURN VALUE
A decimal number.
EXAMPLE
(decimal-places 1.1478349092347 2) => 1.15
SYNOPSIS
(defun decimal-places (num places)
utilities/dynamic-to-amplitude [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Convert a symbol that is a dynamic level between niente and ffff to a corresponding digital amplitude value between 0.0 and 1.0.
ARGUMENTS
- A symbol that is a dynamic level between niente and fff.
OPTIONAL ARGUMENTS
- T or NIL to indicate whether to print a warning when the symbol specified is not recognized as a dynamic. T = warn. Default = T.
RETURN VALUE
A decimal number between 0.0 and 1.0.
EXAMPLE
(dynamic-to-amplitude 'fff) => 0.9
SYNOPSIS
(defun dynamic-to-amplitude (dynamic &optional (warn t))
utilities/econs [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Add a specified element to the end of an existing list.
ARGUMENTS
- A list. - An element to add to the end of the list.
RETURN VALUE
A new list.
EXAMPLE
(econs '(1 2 3 4) 5) => '(1 2 3 4 5)
SYNOPSIS
(defun econs (list new-back)
utilities/env-plus [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Increase all y values of a given list of break-point pairs by a specified amount.
ARGUMENTS
- An envelope in the form of a list of break-point pairs. - A number that is the amount by which all y values of the given envelope are to be increased.
RETURN VALUE
A list of break-point pairs.
EXAMPLE
(env-plus '(0 0 25 11 50 13 75 19 100 23) 7.1) => (0 7.1 25 18.1 50 20.1 75 26.1 100 30.1)
SYNOPSIS
(defun env-plus (env add)
utilities/env-symmetrical [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Create a new list of break-point pairs that is symmetrical to the original around a specified center. If no center is specified, the center value defaults to 0.5
ARGUMENTS
- An envelope in the form of a list of break-point pairs.
OPTIONAL ARGUMENTS
- A number that is the center value around which the values of the new list are to be symmetrical. - A number that is to be the minimum value for the y values returned. - A number that is to be the maximum value for the y values returned.
RETURN VALUE
An envelope in the form of a list of break-point pairs.
EXAMPLE
;;; Default center is 0.5 (env-symmetrical '(0 0 25 11 50 13 75 19 100 23)) => (0 1.0 25 -10.0 50 -12.0 75 -18.0 100 -22.0) ;; Specifying a center of 0 (env-symmetrical '(0 0 25 11 50 13 75 19 100 23) 0) => (0 0.0 25 -11.0 50 -13.0 75 -19.0 100 -23.0) ;;; Specifying minimum and maximum y values for the envelope returned (env-symmetrical '(0 0 25 11 50 13 75 19 100 23) 0 -20 -7) => (0 -7 25 -11.0 50 -13.0 75 -19.0 100 -20)
SYNOPSIS
(defun env-symmetrical (env &optional (centre .5) (min most-negative-double-float) (max most-positive-double-float))
utilities/equal-within-tolerance [ Functions ]
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DESCRIPTION
Test whether the difference between two decimal numbers falls within a specified tolerance. This test is designed to compensate for calculation discrepancies caused by floating-point errors (such as 2.0 vs. 1.9999997), in which the equations should yield equal numbers. It is intended to be used in place of = in such circumstances.
ARGUMENTS
- A first number. - A second number.
OPTIONAL ARGUMENTS
- A decimal value that is the maximum difference allowed between the two numbers that will still return T. Default = 0.000001d0.
RETURN VALUE
T if the two tested numbers are equal within the specified tolerance, otherwise NIL.
EXAMPLE
;; An example of floating-point error (loop for i from 0.0 below 1.1 by 0.1 collect i) => (0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.70000005 0.8000001 0.9000001 1.0000001) ;; Using = (loop for i from 0.0 below 1.1 by 0.1 for j in '(0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0) collect (= i j)) => (T T T T T T T NIL NIL NIL NIL) ;; Using equal-within-tolerance (loop for i from 0.0 below 1.1 by 0.1 for j in '(0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0) collect (equal-within-tolerance i j)) => (T T T T T T T T T T T)
SYNOPSIS
(defun equal-within-tolerance (a b &optional (tolerance 0.000001d0))
utilities/factor [ Functions ]
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DESCRIPTION
Boolean test to check if a specified number is a multiple of a second specified number.
ARGUMENTS
- A number that will be tested to see if it is a multiple of the second number. - A second number that is the base number for the factor test.
RETURN VALUE
T if the first number is a multiple of the second number, otherwise NIL.
EXAMPLE
(factor 14 7) => T
SYNOPSIS
(defun factor (num fac)
utilities/flatten [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Return a list of nested lists of any depth as a flat list.
ARGUMENTS
- A list of nested lists.
RETURN VALUE
A flat list.
EXAMPLE
(flatten '((1 (2 3 4) (5 (6 7) (8 9 10 (11) 12)) 13) 14 15 (16 17))) => (1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17)
SYNOPSIS
(defun flatten (nested-list)
utilities/force-length [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DATE
03-FEB-2011
DESCRIPTION
Create a new a list of a specified new length by adding or removing items at regular intervals from the original list. If adding items and the list contains numbers, linear interpolation will be used, but only between two adjacent items; i.e. not with a partial increment. NB: The function can only create new lists that have a length between 1 and 1 less than double the length of the original list.
ARGUMENTS
- A flat list. - A number that is the new length of the new list to be derived from the original list. This number must be a value between 1 and 1 less than double the length of the original list.
RETURN VALUE
EXAMPLE
;;; Shortening a list (force-length (loop for i from 1 to 100 collect i) 17) => (1 7 13 20 26 32 39 45 51 57 63 70 76 82 89 95 100) ;;; Lengthening a list (force-length (loop for i from 1 to 100 collect i) 199) => (1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21 21.5 22 22.5 23 23.5 24 24.5 25 25.5 26 26.5 27 27.5 28 28.5 29 29.5 30 30.5 31 31.5 32 32.5 33 33.5 34 34.5 35 35.5 36 36.5 37 37.5 38 38.5 39 39.5 40 40.5 41 41.5 42 42.5 43 43.5 44 44.5 45 45.5 46 46.5 47 47.5 48 48.5 49 49.5 50 50.5 51 51.5 52 52.5 53 53.5 54 54.5 55 55.5 56 56.5 57 57.5 58 58.5 59 59.5 60 60.5 61 61.5 62 62.5 63 63.5 64 64.5 65 65.5 66 66.5 67 67.5 68 68.5 69 69.5 70 70.5 71 71.5 72 72.5 73 73.5 74 74.5 75 75.5 76 76.5 77 77.5 78 78.5 79 79.5 80 80.5 81 81.5 82 82.5 83 83.5 84 84.5 85 85.5 86 86.5 87 87.5 88 88.5 89 89.5 90 90.5 91 91.5 92 92.5 93 93.5 94 94.5 95 95.5 96 96.5 97 97.5 98 98.5 99 99.5 100)
SYNOPSIS
(defun force-length (list new-len)
utilities/get-harmonics [ Functions ]
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DESCRIPTION
Return a list of the harmonic partial frequencies in Hertz above a specified fundamental frequency.
ARGUMENTS
- A number that is the fundamental frequency in Hertz.
OPTIONAL ARGUMENTS
keyword arguments - :start-at. An integer that is the number of the first harmonic partial to return. Default = 1. - :min-freq. A number that is the lowest frequency in Hertz to return. Default = 20. - :max-freq. A number that is the highest frequency in Hertz to return. Default = 20000.
RETURN VALUE
A list of numbers that are the frequencies in Hertz of harmonic partials above the same fundamental frequency.
EXAMPLE
;;; Get the first 15 harmonic partials above a fundamental pitch of 64 Hertz, ;;; starting with partial 2, and specifying an upper cut-off of 1010 Hz. (get-harmonics 63 :start-at 2 :max-freq 1010) => (126 189 252 315 378 441 504 567 630 693 756 819 882 945 1008)
SYNOPSIS
(defun get-harmonics (fundamental &key (start-at 1) (min-freq 20) (max-freq 20000))
utilities/get-sublist-indices [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Get the starting position of sublists within a list as though the complete set of items were a flat list.
ARGUMENTS
- A list of lists.
RETURN VALUE
A list of integers that are the indices of the sublists.
EXAMPLE
(get-sublist-indices '((1 2) (3 4 5 6) (7 8 9) (10 11 12 13 14) (15))) => (0 2 6 9 14)
SYNOPSIS
(defun get-sublist-indices (list)
utilities/get-sublist-lengths [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Get the lengths of all sublists in a given list.
ARGUMENTS
- A list of lists.
OPTIONAL ARGUMENTS
- T or NIL to indicate whether to first remove zeros caused by empty sublists from the result.
RETURN VALUE
A list of integers.
EXAMPLE
;; Straightforward usage allows zeros in the result (get-sublist-lengths '((1 2) (3 4 5 6) (7 8 9) (10 11 12 13 14) ())) => (2 4 3 5 0) ;; Setting the optional argument to T removes zeros from the result (get-sublist-lengths '((1 2) (3 4 5 6) (7 8 9) (10 11 12 13 14) ()) t) => (2 4 3 5)
SYNOPSIS
(defun get-sublist-lengths (list &optional (remove-zeros nil))
utilities/hailstone [ Functions ]
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DESCRIPTION
Implementation of the Collatz conjecture (see http://en.wikipedia.org/wiki/Collatz_conjecture ) The Collatz conjecture suggests that by starting with a given number, and if it is even dividing it by two or if it is odd multiplying it by three and adding one, then repeating with the new result, the process will eventually always result in one.
ARGUMENTS
- A number to start with.
RETURN VALUE
A list of the results collected from each iteration starting with the specified number and ending with one.
EXAMPLE
(hailstone 11) => (11 34 17 52 26 13 40 20 10 5 16 8 4 2 1)
SYNOPSIS
(defun hailstone (n)
utilities/hz2ms [ Functions ]
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DESCRIPTION
Convert a frequency in Hertz to the equivalent number of milliseconds.
ARGUMENTS
- A number that is a Hertz frequency.
RETURN VALUE
A number that is the millisecond equivalent of the specified Hertz frequency.
EXAMPLE
(hz2ms 261.63) => 3.8221915
SYNOPSIS
(defun hz2ms (hertz)
utilities/interpolate [ Functions ]
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DESCRIPTION
Get the interpolated value at a specified point within an envelope. The envelope must be specified in the form of a list of break-point pairs.
ARGUMENTS
- A number that is the point within the specified envelope for which to return the interpolated value. - A list of break-point pairs.
OPTIONAL ARGUMENTS
keyword arguments: - :scaler. A number that is the factor by which to scale the values of the break-point pairs in the given envelope before retrieving the interpolated value. Default = 1. - :exp. A number that is the exponent to which the result should be raised. Default = 1. - :warn. T or NIL to indicate whether the method should print a warning if the specified point is outside of the bounds of the x-axis specified in the list of break-point pairs. T = warn. Default = T.
RETURN VALUE
EXAMPLE
;;; Using the defaults (interpolate 50 '(0 0 100 1)) => 0.5 ;;; Specifying a different scaler (interpolate 50 '(0 0 100 1) :scaler 2) => 1.0 ;;; Specifying a different exponent by which the result is to be raised (interpolate 50 '(0 0 100 1) :exp 2) => 0.25
SYNOPSIS
(defun interpolate (point env &key (scaler 1) (exp 1) (warn t))
utilities/list-to-string [ Functions ]
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DESCRIPTION
Convert a list to a string.
ARGUMENTS
- A list.
OPTIONAL ARGUMENTS
- A string that will serve as a separator between the elements. Default = " ". - T or NIL to indicate whether a list value of NIL is to be returned as "NIL" or NIL. T = "NIL" as a string. Default = T.
RETURN VALUE
EXAMPLE
;;; Using defaults (list-to-string '(1 2 3 4 5)) => "1 2 3 4 5" ;;; Specifying a different separator (list-to-string '(1 2 3 4 5) "-") => "1-2-3-4-5" ;;; A NIL list returns "NIL" as a string by default (list-to-string NIL) => "nil" ;;; Setting the second optional argument to NIL returns a NIL list as NIL ;;; rather than as "NIL" as a string (list-to-string NIL "" nil) => NIL
SYNOPSIS
(defun list-to-string (list &optional (separator " ") (nil-as-string t))
utilities/logarithmic-steps [ Functions ]
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DESCRIPTION
Create a list of progressing from the first specified argument to the second specified argument over the specified number of steps using an exponential curve rather than linear interpolation.
ARGUMENTS
- A number that is the starting value in the resulting list. - A number that is the ending value in the resulting list. - An integer that will be the length of the resulting list - 1.
OPTIONAL ARGUMENTS
- A number that will be used as the exponent when determining the exponential interpolation between values. Default = 2.
RETURN VALUE
A list of numbers.
EXAMPLE
(logarithmic-steps 1 100 19) => (1.0 1.3055556 2.2222223 3.75 5.888889 8.638889 12.0 15.972222 20.555555 25.75 31.555555 37.97222 45.0 52.63889 60.88889 69.75 79.22222 89.30556 100.0)
SYNOPSIS
(defun logarithmic-steps (low high num-steps &optional (exponent 2))
utilities/middle [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Get the number value that is middle of two number values.
ARGUMENTS
- A first number. - A second number.
RETURN VALUE
A number.
EXAMPLE
(middle 7 92) => 49.5
SYNOPSIS
(defun middle (lower upper)
utilities/mins-secs-to-secs [ Functions ]
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DESCRIPTION
Derive the number of seconds from a minutes-seconds value that is indicated as a two-item list in the form '(minutes seconds).
ARGUMENTS
- A two-item list of integers in the form '(minutes seconds).
RETURN VALUE
A decimal number that is a number in seconds.
EXAMPLE
(mins-secs-to-secs '(2 1)) => 121.0
SYNOPSIS
(defun mins-secs-to-secs (list)
utilities/move-elements [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DATE
02-Mar-2011
DESCRIPTION
Move the specified elements from one list (if they are present in that list) to another, deleting them from the first.
ARGUMENTS
- A list of elements that are the elements to be moved. - A list from which the specified elements are to be moved and deleted. - A list to which the specified elements are to be moved.
OPTIONAL ARGUMENTS
- A predicate by which to test that the specified elements are equal to elements of the source list. Default = #'eq.
RETURN VALUE
Two values: A first list that is the source list after the items have been moved; a second list that is the target list after the items have been moved.
EXAMPLE
(move-elements '(3 5 8) '(1 2 3 4 5 6 7 8 9) '(a b c d e)) => (1 2 4 6 7 9), (8 5 3 A B C D E)
SYNOPSIS
(defun move-elements (what from to &optional (test #'eq))
utilities/move-to-end [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DATE
22-May-2011
DESCRIPTION
Move a specified element of a given list to the end of the list, returning the new list. NB: If the element exists more than once in the given list, all but on of the occurrences will be removed and only one of them will be placed at the end.
ARGUMENTS
- An item that is an element of the list that is the second argument. - A list.
RETURN VALUE
A list.
EXAMPLE
;;; All unique items (move-to-end 2 '(1 2 3 4 5)) => (1 3 4 5 2) ;;; Duplicate items (move-to-end 2 '(1 2 3 2 4 2 5)) => (1 3 4 5 2)
SYNOPSIS
(defun move-to-end (what list &optional (test #'eql))
utilities/nconc-sublists [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Concatenate corresponding sublists of a given list. Each sublist in the argument should have the same length and number of sublists etc.
ARGUMENTS
A list of lists.
RETURN VALUE
A list of lists.
EXAMPLE
(nconc-sublists '(((1 2) (a b) (cat dog)) ((3 4) (c d) (bird fish)) ((5 6) (e f) (pig cow)))) => ((1 2 3 4 5 6) (A B C D E F) (CAT DOG BIRD FISH PIG COW))
SYNOPSIS
(defun nconc-sublists (lists)
utilities/nearest-power-of-2 [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Return the closest number to the specified value that is a power of two but not greater than the specified value.
ARGUMENTS
- A number.
RETURN VALUE
An integer that is a power of two.
EXAMPLE
(nearest-power-of-2 31) => 16 (nearest-power-of-2 32) => 32 (nearest-power-of-2 33) => 32
SYNOPSIS
(defun nearest-power-of-2 (num)
utilities/octave-freqs [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
A boolean test to determine whether two specified frequencies are octave transpositions of the same pitch class.
ARGUMENTS
- A first number that is a frequency in Hertz. - A second number that is a frequency in Hertz.
OPTIONAL ARGUMENTS
- T or NIL to indicate whether identical frequencies ("unison") are also to be considered octave transpositions of the same pitch class. T = unisons are also octaves. Default = T.
RETURN VALUE
T or NIL.
EXAMPLE
(octave-freqs 261.63 2093.04) => T (octave-freqs 261.63 3000.00) => NIL (octave-freqs 261.63 261.63) => T (octave-freqs 261.63 261.63 nil) => NIL
SYNOPSIS
(defun octave-freqs (freq1 freq2 &optional (unison-also t))
utilities/parse-audacity-label-file-for-loops [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
ARGUMENTS
OPTIONAL ARGUMENTS
RETURN VALUE
EXAMPLE
SYNOPSIS
(defun parse-audacity-label-file-for-loops (label-file)
utilities/parse-wavelab-marker-file-for-loops [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
ARGUMENTS
OPTIONAL ARGUMENTS
RETURN VALUE
EXAMPLE
SYNOPSIS
(defun parse-wavelab-marker-file-for-loops (marker-file &key (sampling-rate 44100) (max-length 1.0))
utilities/partial-freqs [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DATE
13-Dec-2011
DESCRIPTION
A Boolean test to determine whether either of two specified frequencies can be considered a harmonic partial of the other.
ARGUMENTS
- A first frequency in Hertz. - A second frequency in Hertz.
OPTIONAL ARGUMENTS
- T or NIL to indicate whether identical frequencies ("unison") are also to be considered partials of each other. T = unison are partials. Default = T.
RETURN VALUE
T if one of the frequencies has the ratio of a harmonic partial to the other, otherwise NIL.
EXAMPLE
(partial-freqs 300 900) => T (partial-freqs 300 700) => NIL (partial-freqs 300 300) => T (partial-freqs 300 300 nil) => NIL
SYNOPSIS
(defun partial-freqs (freq1 freq2 &optional (unison-also t))
utilities/power-of-2 [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Test whether the specified number is a power of two and return the logarithm of the specified number to base 2. This method returns two values: T or NIL for the test and a decimal that is the logarithm of the specified number to base 2.
ARGUMENTS
- A number.
RETURN VALUE
Two values: T or NIL for the test and a decimal number that is the logarithm of the specified number to base 2.
EXAMPLE
(power-of-2 16) => T, 4.0 (power-of-2 17.3) => NIL, 4.1127
SYNOPSIS
(defun power-of-2 (float)
utilities/pts2cm [ Functions ]
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DESCRIPTION
Convert a specified number of points to a length in centimeters at a resolution of 72ppi
ARGUMENTS
- A number.
RETURN VALUE
A number.
EXAMPLE
(pts2cm 150) => 5.2916665
SYNOPSIS
(defun pts2cm (points)
utilities/random-amount [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Return a random number from within a total range of <percent> of the given number, centering around zero. Thus, if the <number> is 100, and the <percent> is 5, the results will be a random number between -2.5 and +2.5.
ARGUMENTS
A number.
OPTIONAL ARGUMENTS
A number that will be a percent of the given number.
RETURN VALUE
A random positive or negative number.
EXAMPLE
;;; Using the default will return numbers within a 5% span of the given number, ;;; centering around zero. With 100 that means between -2.5 and +2.5. (loop repeat 10 collect (random-amount 100)) => (0.7424975 -1.4954442 -1.7126495 1.5918689 -0.43478793 -1.7916341 -1.9115914 0.8541988 0.057197176 2.0713913) ;;; Specifying 10% of 80 will return random numbers between -4.0 and +4.0 (loop repeat 10 collect (random-amount 80 10)) => (-0.66686153 3.0387697 3.4737322 -2.3753185 -0.8495751 -0.47580242 -0.25743783 -1.1395472 1.3560238 -0.5958566)
SYNOPSIS
(defun random-amount (number &optional (percent 5))
utilities/random-from-list [ Functions ]
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DESCRIPTION
Return a random element from a specified list of elements.
ARGUMENTS
- A list.
OPTIONAL ARGUMENTS
- An integer can be passed stating the length of the list, for more efficient processing. NB: There is no check to ensure this number is indeed the length of the list. If the number is less than the length of the list, only elements from the first part of the list will be returned. If it is greater than the length of the list, the method may return NIL.
RETURN VALUE
An element from the specified list.
EXAMPLE
(random-from-list '(3 5 7 11 13 17 19 23 29)) => 13
SYNOPSIS
(defun random-from-list (list &optional list-length) ; for efficiency
utilities/randomise [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Return a random decimal number close to the number specified (within a certain percentage of that number's value).
ARGUMENTS
- A number.
OPTIONAL ARGUMENTS
- A number that is a percentage value, such that any random number returned will be within that percentage of the original number's value. Default = 5.
RETURN VALUE
A decimal number.
EXAMPLE
(loop repeat 10 collect (randomise 100)) => (99.413795 99.15346 98.682014 100.76199 97.74929 99.05693 100.59494 97.96452 100.42091 100.01329)
SYNOPSIS
(defun randomise (number &optional (percent 5))
utilities/read-from-file [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Read a Lisp expression from a file. This is determined by the Lisp parenthetical syntax.
ARGUMENTS
- A string that is a file name including directory path and extension.
RETURN VALUE
The Lisp expression contained in the file.
EXAMPLE
(read-from-file "/path/to/lisp-lorem-ipsum.txt") => (LOREM IPSUM DOLOR SIT AMET CONSECTETUR ADIPISCING ELIT CRAS CONSEQUAT CONVALLIS JUSTO VITAE CONSECTETUR MAURIS IN NIBH VEL EST TEMPUS LOBORTIS SUSPENDISSE POTENTI SED MAURIS MASSA ADIPISCING VITAE DIGNISSIM CONDIMENTUM VOLUTPAT VEL FELIS FUSCE AUGUE DUI PULVINAR ULTRICIES IMPERDIET SED PHARETRA EU QUAM INTEGER IN VULPUTATE VELIT ALIQUAM ERAT VOLUTPAT VIVAMUS SIT AMET ORCI EGET EROS CONSEQUAT TINCIDUNT NUNC ELEMENTUM ADIPISCING LOBORTIS MORBI AT LOREM EST EGET MATTIS ERAT DONEC AC RISUS A DUI MALESUADA LOBORTIS AC AT EST INTEGER AT INTERDUM TORTOR VIVAMUS HENDRERIT CONSEQUAT AUGUE QUISQUE ALIQUAM TELLUS NEC VESTIBULUM LOBORTIS RISUS TURPIS LUCTUS LIGULA IN BIBENDUM FELIS SEM PULVINAR DOLOR VIVAMUS RHONCUS NISI GRAVIDA PORTA VULPUTATE IPSUM LACUS PORTA RISUS A VULPUTATE MAGNA JUSTO A EST)
SYNOPSIS
(defun read-from-file (file)
utilities/reflect-list [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Order a list of numbers from least to greatest, then transpose the list so that if an element is the second lowest, it will be replaced by the second highest etc.
ARGUMENTS
- A list or numbers.
RETURN VALUE
A list of numbers.
EXAMPLE
(reflect-list '(1 4 3 5 9 6 2 7 8 8 9)) => (9 6 7 5 1 4 8 3 2 2 1)
SYNOPSIS
(defun reflect-list (list)
utilities/remove-all [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Remove all of the specified elements from a list, returning a list containing only those elements that are not in the first argument list.
ARGUMENTS
- A first list that is the list of items to remove. - A second list that is the original list.
OPTIONAL ARGUMENTS
- A predicate for testing equality between the elements of the two lists. Default = #'eq.
RETURN VALUE
A list.
EXAMPLE
(remove-all '(3 5 8 13) '(1 2 3 4 5 6 7 8 9 10 11 12 13)) => (1 2 4 6 7 9 10 11 12)
SYNOPSIS
(defun remove-all (rm-list list &optional (test #' eq))
utilities/remove-elements [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Remove a specified number of elements from a given list starting at a specified position (0-based) within the list.
ARGUMENTS
- A list. - An integer that is the 0-based position within that list that will be the first element to be removed. - An integer that is the number of elements to remove.
RETURN VALUE
A list.
EXAMPLE
(remove-elements '(1 2 3 4 5 6 7) 2 4) => (1 2 7)
SYNOPSIS
(defun remove-elements (list start how-many)
utilities/remove-more [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Remove all instances of a list of specified elements from an original list. The predicate used to test the presence of the specified elements in the original list must be specified by the user (such as #'eq, #'equalp, #'= etc.)
ARGUMENTS
- A list. - A predicate with which to test the presence of the specified elements. - A sequence of elements to be removed from the given list.
RETURN VALUE
A list.
EXAMPLE
(remove-more '(1 2 3 4 5 5 5 6 7 7 8) #'= 5 7 2) => (1 3 4 6 8)
SYNOPSIS
(defun remove-more (list test &rest remove)
utilities/repeat-env [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Create a new list by repeating the y values of a list of break-point pairs a specified number of times over the same total x-axis span of the original envelope. A quick ramp is inserted between repeats to ensure that all x-axis values are unique and incremental. If the optional argument is set to T, the method will reverse the order of every second repeat.
ARGUMENTS
- An envelope in the form of a list of break-point pairs. - An integer that is the number of times the elements of the given envelope should be repeated in the new list.
OPTIONAL ARGUMENTS
- T or NIL to indicate whether every second repetition of the original envelope should be returned in reverse order. T = reverse. Default = NIL.
RETURN VALUE
- A new envelope in the form of a list of break-point pairs.
EXAMPLE
(repeat-env '(0 1 50 2 100 3) 3) => (0.0 1 16.666666 2 33.333332 3 34.333332 1 50.0 2 66.666664 3 67.666664 1 83.33333 2 100.0 3) (repeat-env '(0 1 50 2 100 3) 3 t) => (0.0 1 16.666666 2 33.333332 3 50.0 2 66.666664 1 83.33333 2 100.0 3)
SYNOPSIS
(defun repeat-env (env num-times &optional reflected)
utilities/replace-elements [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Replace the elements in list between start and end (inclusive) with the new list.
ARGUMENTS
- A list. - An integer that is first position of the segment of the original list to be replaced. - An integer that is the last position of the segment of the original list to be replaced. - A list that is to replace the specified segment of the original list. This list can be of a different length than that of the segment of the original specified by the start and end positions.
RETURN VALUE
A list.
EXAMPLE
(replace-elements '(1 2 3 4 5 6 7 8 9) 3 7 '(dog cat goldfish)) => (1 2 3 DOG CAT GOLDFISH 9)
SYNOPSIS
(defun replace-elements (list start end new)
utilities/reverse-env [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Reverse the order of y values in a list of break-point pairs.
ARGUMENTS
- An envelope in the form of a list of break-point pairs.
RETURN VALUE
An envelope in the form of a list of break-point pairs.
EXAMPLE
(reverse-env '(0 0 25 11 50 13 75 19 100 23)) => (0 23 25 19 50 13 75 11 100 0)
SYNOPSIS
(defun reverse-env (env)
utilities/round-if-close [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Round a decimal number if it is within a given tolerance to the next whole number.
ARGUMENTS
- A decimal number.
OPTIONAL ARGUMENTS
- If the given number is this amount or less than the nearest whole number, round the given number to the nearest whole number.
RETURN VALUE
If the given number is within the tolerance, return the number, otherwise return the nearest whole number.
EXAMPLE
(round-if-close 1.999998) => 1.999998 (round-if-close 1.999999) => 2
SYNOPSIS
(defun round-if-close (num &optional (tolerance 0.000001))
utilities/scale-env [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Scale either the x-axis values, the data values, or both of a list of break-point pairs by specified factors.
ARGUMENTS
- An envelope in the form of a list of break-point pairs. - A number that is the factor by which the y values (data segment of the break-point pairs) are to be scaled.
OPTIONAL ARGUMENTS
keyword arguments: - :y-min. A number that is the minimum value for all y values after scaling. - :y-max. A number that is the maximum value for all y values after scaling. - :x-scaler. A number that is the factor by which to scale the x-axis values of the break-point pairs. - :x-min. A number that is the minimum value for all x values after scaling. NB: This optional argument can only be used if a value has been specified for the :x-scaler. - :x-max. A number that is the maximum value for all x values after scaling. NB: This optional argument can only be used if a value has been specified for the :x-scaler.
RETURN VALUE
An envelope in the form of a list of break-point pairs.
EXAMPLE
;;; Scaling only the y values. (scale-env '(0 53 25 189 50 7 75 200 100 3) 0.5) => (0 26.5 25 94.5 50 3.5 75 100.0 100 1.5) ;;; Scaling the y values and setting a min and max for those values (scale-env '(0 53 25 189 50 7 75 200 100 3) 0.5 :y-min 20 :y-max 100) => (0 26.5 25 94.5 50 20 75 100 100 20) ;;; Scaling only the x-axis values (scale-env '(0 53 25 189 50 7 75 200 100 3) 1.0 :x-scaler 2) => (0 53.0 50 189.0 100 7.0 150 200.0 200 3.0) ;;; Scaling the x values and setting a min and max for those values (scale-env '(0 53 25 189 50 7 75 200 100 3) 1.0 :x-scaler 2 :x-min 9 :x-max 90) => (9 53.0 50 189.0 90 7.0 90 200.0 90 3.0)
SYNOPSIS
(defun scale-env (env y-scaler &key x-scaler (x-min most-negative-double-float) (y-min most-negative-double-float) (x-max most-positive-double-float) (y-max most-positive-double-float))
utilities/secs-to-mins-secs [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
ARGUMENTS
OPTIONAL ARGUMENTS
RETURN VALUE
EXAMPLE
SYNOPSIS
(defun secs-to-mins-secs (seconds &key (separator ":") (same-width nil))
utilities/semitones [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Return the sample-rate conversion factor required for transposing an audio file by a specific number of semitones. The number of semitones can be given as a decimal number, and may be positive or negative.
ARGUMENTS
- A number of semitones.
OPTIONAL ARGUMENTS
- A number that is the factor required to transpose by an octave. Default = 2.0. - A number that is the number of semitones per octave. Default = 12.
RETURN VALUE
A number.
EXAMPLE
;;; Usage with default values (semitones 3) => 1.1892071 ;;; Specifying a different number of semitones per octave (semitones 3 2.0 13) => 1.1734605 ;;; Specifying a different factor for transposing by an octave (semitones 3 4.0) => 1.4142135 ;;; Fractional semitones are allowed (semitones 3.72) => 1.2397077 ;;; Negative semitones are also allowed (semitones -3.72) => 0.80664176
SYNOPSIS
(defun semitones (st &optional (octave-size 2.0) (divisions-per-octave 12))
utilities/setf-last [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Change the last element in a given list to a specified new element.
ARGUMENTS
- A list. - The new last element of that list.
RETURN VALUE
Returns the new last element.
EXAMPLE
(let ((l '(1 2 3 4 5))) (setf-last l 'dog) l) => (1 2 3 4 DOG)
SYNOPSIS
(defmacro setf-last (list new-last)
utilities/sort-symbol-list [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Sort a list of symbols alphabetically ascending, case-insensitive.
ARGUMENTS
A list of symbols.
RETURN VALUE
The same list of symbols sorted alphabetically ascending, case-insensitive.
EXAMPLE
(sort-symbol-list '(Lorem ipsum dolor sit amet consectetur adipiscing)) => (ADIPISCING AMET CONSECTETUR DOLOR IPSUM LOREM SIT)
SYNOPSIS
(defun sort-symbol-list (list)
utilities/splice [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Insert the elements of a first list into a second list beginning at a specified index (0-based).
ARGUMENTS
- A list that contains the elements to be inserted into the second list. - A list into which the elements of the first argument are to be inserted. - An integer that is the index within the second list where the elements are to be inserted.
RETURN VALUE
- A list.
EXAMPLE
(splice '(dog cat goldfish) '(1 2 3 4 5 6 7 8 9) 3) => (1 2 3 DOG CAT GOLDFISH 4 5 6 7 8 9)
SYNOPSIS
(defun splice (elements into-list where)
utilities/split-groups [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Create a list consisting of as many repetitions of a specified number as will fit into a given greater number, with the last item in the new list being the value of any remainder.
ARGUMENTS
- A number that is to be split into repetitions of a specified smaller number (the second argument). - The number that is to be the repeating item in the new list. This number must be smaller than the first number.
RETURN VALUE
A list consisting of repetitions of the specified number, with the last element being any possible remainder.
EXAMPLE
(split-groups 101 17) => (17 17 17 17 17 16)
SYNOPSIS
(defun split-groups (num divider)
utilities/split-into-sub-groups [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Create a new list consisting of sublists made from the elements of the original flat list, whose lengths are determined by the second argument to the function. NB: The lengths given in the second argument are not required to add up to the length of the original list. If their sum is less than the original list, the resulting list of sublists will only contain a segment of the original elements. If their sum is greater than the length of the original list, the last sublist in the new list will be shorter than the corresponding group value.
ARGUMENTS
- A flat list. - A list of integers that are the lengths of the consecutive subgroups into which the original list is to be divided.
RETURN VALUE
A list of lists.
EXAMPLE
;; Used with a list of subgroup lengths whose sum is equal to the length of the ;; original list (split-into-sub-groups '(1 2 3 4 5 6 7 8 9 10) '(2 2 3 2 1)) => ((1 2) (3 4) (5 6 7) (8 9) (10)) ;; Used with a list of subgroup lengths whose sum is less than the length of the ;; original list (split-into-sub-groups '(1 2 3 4 5 6 7 8 9 10) '(2 1)) => ((1 2) (3)) ;; Used with a list of subgroup lengths whose sum is greater than the length of ;; the original list (split-into-sub-groups '(1 2 3 4 5 6 7 8 9 10) '(2 3 17)) => ((1 2) (3 4 5) (6 7 8 9 10))
SYNOPSIS
(defun split-into-sub-groups (list groups)
utilities/split-into-sub-groups2 [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Create a new list of lists by splitting the original flat list into sublists of the specified length. NB: The length given as the second argument is not required to be fit evenly into the length of the original flat list. If the original list is not evenly divisible by the specified length, the resulting list of sublists will contain a final sublist of a different length.
ARGUMENTS
- A flat list. - An integer that is the length of each of the sublists to be created.
RETURN VALUE
A list of lists.
EXAMPLE
;; The second argument fits evenly into the length of the original list. (split-into-sub-groups2 '(1 2 3 4 5 6 7 8 9 10 11 12) 3) => ((1 2 3) (4 5 6) (7 8 9) (10 11 12)) ;; The second argument does not fit evenly into the length of the original ;; list. (split-into-sub-groups2 '(1 2 3 4 5 6 7 8 9 10 11 12) 5) => ((1 2 3 4 5) (6 7 8 9 10) (11 12))
SYNOPSIS
(defun split-into-sub-groups2 (list length)
utilities/split-into-sub-groups3 [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Split a given flat list into sublists of the specified length, putting any remaining elements, if there are any, into the last sublist.
ARGUMENTS
- A flat list. - An integer that is the length of the new sublists.
RETURN VALUE
A list of lists.
EXAMPLE
(split-into-sub-groups3 '(1 2 3 4 5 6 7 8 9 10 11 12) 3) => ((1 2 3) (4 5 6) (7 8 9) (10 11 12)) (split-into-sub-groups3 '(1 2 3 4 5 6 7 8 9 10 11 12) 5) => ((1 2 3 4 5) (6 7 8 9 10 11 12))
SYNOPSIS
(defun split-into-sub-groups3 (list length)
utilities/srt [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Return the semitone transposition for a given sampling rate conversion factor.
ARGUMENTS
- A number that is a sample-rate conversion factor.
OPTIONAL ARGUMENTS
- A number that is the factor required for transposing one octave. - A number that is the number of scale degrees in an octave.
RETURN VALUE
A number.
EXAMPLE
;;; Using the defaults (srt 1.73) => 9.4893 ;;; Using a sample-rate conversion factor of 4.0 for the octave and specifying ;;; 13 divisions of the octave (srt 1.73 4.0 13) => 5.14
SYNOPSIS
(let ((last8vesize 0) (log8ve 0.0)) ;; so we don't have to recalculate each time (defun srt (srt &optional (octave-size 2.0) (divisions-per-octave 12) ;; MDE Tue Feb 7 16:59:45 2012 -- round so we don't get tiny ;; fractions of semitones due to float inaccuracies? (round-to 0.0001))
utilities/string-replace [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Replace specified segments of a string with a new specified string.
ARGUMENTS
- A string that is the string segment to be replaced. - A string that is the string with which the specified string segment is to be replaced. - The string in which the specified segment is to be sought and replaced.
RETURN VALUE
A string.
EXAMPLE
(string-replace "flat" "\\flat" "bflat clarinet") => "b\\flat clarinet"
SYNOPSIS
(defun string-replace (what with string)
utilities/swap-elements [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Swap the order of each consecutive pair of elements in a list.
ARGUMENTS
- A list.
RETURN VALUE
A list.
EXAMPLE
(swap-elements '(1 2 3 4 5 6 7 8 9 10)) => (2 1 4 3 6 5 8 7 10 9) (swap-elements '(1 2 3 4 5 6 7 8 9)) => (2 1 4 3 6 5 8 7 9)
SYNOPSIS
(defun swap-elements (list)
utilities/wavelab-to-audacity-marker-file [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
ARGUMENTS
OPTIONAL ARGUMENTS
RETURN VALUE
EXAMPLE
SYNOPSIS
(defun wavelab-to-audacity-marker-file (file &optional (sampling-rate 44100))
utilities/wrap-list [ Functions ]
[ Top ] [ utilities ] [ Functions ]
DESCRIPTION
Shift the elements of a list to start at a specified position and wrap to the beginning of the list to the list's tail.
ARGUMENTS
- A list. - An integer which is the 0-based position in the original list where the new list is to begin.
RETURN VALUE
A list.
EXAMPLE
(wrap-list '(1 2 3 4 5 6 7 8 9) 4) => (5 6 7 8 9 1 2 3 4)
SYNOPSIS
(defun wrap-list (list start)