From 8dbec761cf858ea65900c8a094599857208d8c3a Mon Sep 17 00:00:00 2001 From: "N.N." Date: Tue, 5 Jan 2010 22:49:36 +0000 Subject: svn path=/trunk/; revision=12907 --- desiredata/extra/expr~/README.txt | 97 --------------------------------------- 1 file changed, 97 deletions(-) delete mode 100644 desiredata/extra/expr~/README.txt (limited to 'desiredata/extra/expr~/README.txt') diff --git a/desiredata/extra/expr~/README.txt b/desiredata/extra/expr~/README.txt deleted file mode 100644 index bf84f2ae..00000000 --- a/desiredata/extra/expr~/README.txt +++ /dev/null @@ -1,97 +0,0 @@ - -You can get more information on the expr object at -http://www.crca.ucsd.edu/~yadegari/expr.html - ------------ - -New if Version 0.4 - --access to variables (made by value object) --multiple expression separated by ; --added the following shorthands: - $y or $y1 = $y1[-1] and $y2 = $y2[-1] --new functions: - if - conditional evaluation - cbrt - cube root - erf - error function - erfc - complementary error function - expm1 - exponential minus 1, - log1p - logarithm of 1 plus - isinf - is the value infinite, - finite - is the value finite - isnan -- is the resut a nan (Not a number) - copysign - copy sign of a number - ldexp - multiply floating-point number by integral power of 2 - imodf - get signed integral value from floating-point number - modf - get signed fractional value from floating-point number - drem - floating-point remainder function - - Thanks to Orm Finnendahl for adding the following functions: - fmod - floating-point remainder function - ceil - ceiling function: smallest integral value not less than argument - floor - largest integral value not greater than argument - ------------- - -New in Version 0.3 --Full function functionality - ------------- - -The object "expr" is used for expression evaluaion of control data. - -Expr~ and fexpr~ are extentions to the expr object to work with vectors. -The expr~ object is designed to efficiently combine signal and control -stream processing by vector operations on the basis of the block size of -the environment. - -fexpr~ object provides a flexible mechanism for building FIR and -IIR filters by evaluating expressions on a sample by sample basis -and providing access to prior samples of the input and output audio -streams. When fractional offset is used, fexpr~ uses linear interpolation -to determine the value of the indexed sample. fexpr~ evaluates the -expression for every single sample and at every evaluation previous -samples (limited by the audio vector size) can be accessed. $x is used to -denote a singnal input whose samples we would like to access. The syntax -is $x followed by the inlet number and indexed by brackets, for example -$x1[-1] specifies the previous sample of the first inlet. Therefore, -if we are to build a simple filter which replaces every sample by -the average of that sample and its previous one, we would use "fexpr~ -($x1[0]+$x1[-1])/2 ". For ease of when the brackets are omitted, the -current sample is implied, so we can right the previous filter expression -as follows: " fexpr~ ($x1+$x1[-1])/2". To build IIR filters $y is used -to access the previous samples of the output stream. - -The three objects expr, expr~, and fexpr~ are implemented in the same object -so the files expr~.pd_linux and fexpr~.pd_linux are links to expr.pd_linux -This release has been compiled and tested on Linux 6.0. - --------- - -Here are some syntax information: (refer to help-expr.pd for examples) - -Syntyax: -The syntax is very close to how expression are written in -C. Variables are specified as follows where the '#' stands -for the inlet number: -$i#: integer input variable -$f#: float input variable -$s#: symbol input variable - -Used for expr~ only: -$v#: signal (vector) input (vector by vector evaluation) - -Used for fexpr~ only: -$x#[n]: the sample from inlet # indexed by n, where n has to - satisfy 0 => n >= -vector size, - ($x# is a shorthand for $x#[0], specifying the current sample) - -$y#[n]: the output value indexed by n, where n has to - satisfy 0 > n >= -vector size, - $y[n] is a shorthand for $y1[n] - - -I'll appreciate hearing about bugs, comments, suggestions, ... - -Shahrokh Yadegari (sdy@ucsd.edu) -7/10/02 -- cgit v1.2.1