02_44_2
additional parameters: icycle


This is a realization of the Shepard tone or endless glissando
that utilizes TABLE(I) and PHASOR. The tables contain a
bell-shaped and an exponential functions. The variable
icycle controls the speed of incremental indexing. 

Cycle time studies. 
The score file explores how different values of the variable
icycle affect the sound.
For the first tone the sampling index advances 1/100th of a
cycle. In the second tone the index moves at 1/50th and in the
last setting it increases to 1/25th of a cycle. The duration is
20 seconds for each note.

The bell-shaped function cannot be generated by any of Csound's
GEN routines directly. There is a way though, to obtain a table
of an arbitrary mathematical function by making one extra step. 

First, a purely mathematical orchestra calculates the table
values. After this run, the desired table exists as a datafile.
From now on, any instrument can make use of the new table. GEN 01
retrieves the values of the soundfile into a function table. Like
all GEN routines, GEN 01 by default rescales the given values to
the range (-1 < x < 1). Loaded into internal memory, the function
table can be used like any wave or envelope function table. 

In instrument 02_44_2, the datafile Sflib/88_01_2.TAB is called
up by GEN 01 to give the bell-shaped function. 

A subdirectory Sflib (Soundfilelibrary) within the main soundfile
directory is useful to protect mathematical and other special
audio files from wildcard operations on the soundfile directory.
(Vercoe 1993: morefiles/ENDLESS.ORC; Vercoe 1993: morefiles/
risset4.orc)


(flowchart)
(.orc and .sco files)
