+++ /dev/null
-/************************************************************************
- ************************************************************************
- FAUST library file
- Copyright (C) 2010-2011 GRAME, Centre National de Creation Musicale
- ---------------------------------------------------------------------
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU Lesser General Public License as
- published by the Free Software Foundation; either version 2.1 of the
- License, or (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA.
- ************************************************************************
- ************************************************************************/
-
-declare name "Reduce Library";
-declare author "Yann Orlarey (orlarey at grame.fr)";
-declare copyright "Grame";
-declare version "0.1";
-declare license "LGPL";
-
-
-//---------------------------------------------------------------
-// Provides various operations on block of samples
-// using a high order 'reduce(op, n)' fold-like function :
-//
-// sumn(n) : the sum of a block of n input samples
-// maxn(n) : the max of a block of n input samples
-// minn(n) : the min of a block of n input samples
-// mean(n) : the mean of a block of n input samples
-// RMS(n) : the RMS of a block of n input samples
-//---------------------------------------------------------------
-
-
-
-//---------------------------------------------------------------
-// reduce (op, n, x)
-//---------------------------------------------------------------
-// Fold-like high order function. Apply a binary operation <op>
-// on a block of <n> consecutive samples of a signal <x>.
-// For example : reduce(max,128) will compute the maximun of each
-// block of 128 samples. Please note that the resulting
-// value, while produced continuously, will be constant for
-// the duration of a block. A new value is only produced
-// at the end of a block. Note also that blocks should be of at
-// least one sample (n>0).
-reduce(op, n, x) = compute ~ (_,_,_) : (!,!,_)
- with {
- compute (acc, count, val) =
- if(count<n, op(acc,x), x), // new acc
- if(count<n, count+1, 1), // new count
- if(count<n, val, acc); // new val
- if (c, then, else) = select2(c, else, then);
- };
-
-
-//---------------------------------------------------------------
-// reducemap (op, foo, n, x)
-//---------------------------------------------------------------
-// Like reduce but a foo function is applied to the result. From
-// a mathematical point of view :
-// reducemap(op,foo,n) is equivalent to reduce(op,n):foo
-// but more efficient.
-reducemap(op, foo, n, x) = compute ~ (_,_,_) : (!,!,_)
- with {
- compute (acc, count, val) =
- if(count<n, op(acc,x), x), // new acc
- if(count<n, count+1, 1), // new count
- if(count<n, val, foo(acc)); // new val
- if (c, then, else) = select2(c, else, then);
- };
-
-
-// the sum of the amplitudes of the input signal
-sumn(n) = reduce(+,n);
-
-// the maximum amplitude of the input signal
-maxn(n) = reduce(max,n);
-
-// the minimum amplitude of the input signal
-minn(n) = reduce(min,n);
-
-// the average amplitude of the input signal
-mean(n) = reducemap(+, /(n), n);
-
-// RMS
-RMS(n) = float : ^(2) : reducemap(+, (/(n):sqrt), n);
-