Class:            FourierSummation

Environment:      Siren
 Superclass:         Siren.Function
 Category:         Music-Functions
 Instance variables:   myForm myArray lazy
Indexed variables:   objects

Instances of FourierSummation are functions that interpret their points as 3-element arrays (harmonic, amplitude, phase), and sum sine waves into their data array based on the fourier summation of these components.

Instance variables:
   myForm      

my function plot--default size = 1024@180
   myArray       my value array--default length = 1024
   lazy do I cache my values (eager) or cmopute them on the fly (lazy)?

Example:
   | fcn |
   fcn := FourierSummation from: #((1 1 0) (3 0.3 0) (5 0.2 0)
                     (7 0.15 0) (9 0.11 0) (11 0.09 0)).
   Transcript show: (fcn at: 0.14) printString; cr.

initialize-release

initialize: size
   Initialize the receiver for the given size.

computing

computeCurve
   Compute the block by sine summation--set the values in the cached array.

computeValueAt: anIndex
   Compute the answer by sine summation.

accessing

add: a3DPoint
   Add the argument to the receiver's point collection.

at: theIndex
   Answer the value from my array--assume an index in the range 0 to 1

MetaClass:         FourierSummation class

instance creation

default
   Answer a default instance of the receiver class.

from: anArrayOfZPoints
   Answer a sum-of-sines function with the given points.

examples

fourierExample
   Make a Sine summation that approaches a square wave

fourierViewExample
   Make a Sine summation that approaches a square wave and open a view on it.