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+===== Math expression parser =====
+==== Motivation ====
+In order to fill a wavetable with waves, a tool is needed to make this task as simple and effective as possible.
+So the idea to do it with the help of some math was born. An expression parser takes a formula as input and after evaluation all wavetable data gets visualized and can be dumped to the blofeld.
+==== How it works ====
+Two variables are set automatically, that is:
+x moves from 0.0 to 1.0 for all 128 samples in a wave.a
+y moves from 0.0 to 1.0 for each table entry in the range [0..64]
+==== Overview of implemented operators ====
+  * Basic operators: +, -, * (multiply) and / (divide)
+  * % Mod operator
+  * Exponentiation operator: ^
+  * Negation: unary -
+  * Assignment: =
+  * Log functions: log(), log2(), ln(), exp()
+  * Transcendental functions: sin(), cos(), tan(), asin(), acos(), atan(), sinh(), cosh(), tanh(), asinh(), acosh(), atanh()
+  * Square root function: sqrt()
+  * [[hgk:round|Rounding functions]]: ceil(), floor(), round(), trunc(), rint(), near()
+  * Angular conversion functions: dtor(), rtod()
+  * Absolute value function: abs()
+  * Constants: pi
+==== Example expressions ====
+  * Sawtooth: 2*x-1
+  * Rectangle: 2*round(x)-1
+  * Approximated sawtooth
+  * http://en.wikipedia.org/wiki/Sawtooth_wave
+    * 0.5 - 1/pi * (sin(2*pi*x) + sin(4*pi*x)/2 + sin(6*pi*x)/3  + sin(8*pi*x)/4) + sin(10*x*pi)/5
+    * 2/pi * (-sin(2*pi*x) + sin(4*pi*x)/2 - sin(6*pi*x)/3  + sin(8*pi*x)/4) - sin(10*x*pi)/5
+    * Approximated rectangle
+    * http://en.wikipedia.org/wiki/Square_wave
+      * 4/pi * (sin(2*pi*x) + sin(6*pi*x)/3 + sin(10*pi*x)/5 + sin(14*pi*x)/7 + sin(18*pi*x)/9
+    * 3-bit sampled sine function: round(sin(x*2*pi) * 4)/4
+==== Gaussian tone burst ====
+Gauss-Funktion für einen Vektor
+http://etools.fernuni.ch/matlab/matlab3/de/html/loops_learningObject4.html
+<code>
+Mittelwert m und Standardabweichung s
+s=0.5
+m=pi/2
+/(2*sqrt(2*pi)) * exp(-1/2*((x*pi-m)/s)^2) * sin(16*pi*x)
+</code>
+==== Implementation ====
+[[http://apptree.net/parser.htm|GCMathParser]] is a Cocoa class © 2006-2008 Graham Cox
+It uses ZExpParser MacZoop expression parser
+The Xcode project compiles fine, just set SDKROOT = macosx and replace cString with UTF8String (in general is a much better choice when converting arbitrary NSStrings into 8-bit representations)
+<code>
+GCMathParser* parser = [GCMathParser parser];
+NSString* expression = @"sin(x)";
+for (int sampleIndex = 0; sampleIndex < 64; sampleIndex++) {
+	double x = sampleIndex / 64.;
+    [parser setSymbolValue:x forKey:@"x"];
+    wave[sampleIndex] = [parser evaluate:expression];
+}
+</code>
+Another parser on the web is https://github.com/davedelong/DDMathParser