WaveWarp 2.0 Component
      
Signal Generators:
Random Pulse Control Generator (A)
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Functional Description
Generates a sequence
of rectangular pulses, (pseudo-)randomly distributed in time,
with an
amplitude nominally between 0 and 1 (for use as an "Amplitude" controller).
NOTE: the sample rate at which this component is executed can be arbitrarily set via the
"Sample-rate setting for Signal Generators and
Input ASCII files" button
(or the "Sample-Rate Setting" command under the "Edit" menu) on the toolbar, which is
activated whenever the component is selected on the DrawingBoard.
Equivalently, it can be set via the dialog box which (i) appears
when the component is initially
dragged on to the DrawingBoard or (ii) is activated using the right-mouse-button when
the component is selected on the DrawingBoard.
This procedure allows the component to either (i) enforce
a user-determined sample rate on the downstream component(s), or (ii) to inherit the sample rate from
the downstream component(s). Different signal generators can run at different
sample rates on a DrawingBoard, as long as the rules of connectivity
for multiple sample rates are adhered to (see the
WaveWarp Users' Guide
for more information.)
The characteristics of the random pulse train are adjustable via
the Parameter Window, as summarised in the
following table.
| Parameter | Purpose |
|---|
| "Pulse average separation" slider |
Adjusts the average duration between successive pulses,
given by the slider value multiplied
by the "Max separation" range selection.
The actual time elapsed between two successive pulses,
is determined by a
(pseudo-)random sequence with a mean value equal to the selected
resultant "Total separation".
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| "Pulse width" slider |
Adjusts the duration of each pulse,
given by the slider value multiplied
by the "Max width" range selection.
The resultant "Total width" corresponds to the duration
(measured from the start of the pulse).
The signal ouput will be equal to the selected "Amplitude" for the
duration of the pulse, and zero thereafter.
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| "Amplitude" slider |
Adjusts the amplitude of the output signal.
Depending on the selected "Range", the control signal output
will be scaled either between
-1 and 1, or between 0 and 1.
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| "Modulation" checkbox |
If enabled, the
"Range"
selection is automatically disabled, and the "Amplitude" slider becomes
a "Depth" slider. The control signal ouput will be automatically scaled
over the range from 0 to 1.
The "Depth" determines the fraction of this range over which the
pulse sequence will be
mapped. Maximum "Depth" (a value of 1) implies that the pulse sequence will be
mapped on to the entire range from 0 to 1, thereby maximising the signal variation.
Minimum "Depth" (a value of 0) implies no mapping, thereby minimising
the signal variation (i.e. constant
output). An intermediate value, say 0.2, implies that the ouput of the
pulse sequence
will be
mapped on to the upper 20% of the output range, and so forth.
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| Plot window |
Displays a representative portion of the time-history of the pulse sequence,
reflecting the time scaling due to the
"Pulse average separation"
and "Pulse width" sliders,
and the amplitude scaling due to
the
"Amplitude" or "Depth" slider.
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Algorithm
Utilizes a pseudo-random number generator using the system clock as
a "seed".
Signal Implementations
| Audio signals | Control signals | Description |
|---|
| n/a | single output | Generates a control signal with an amplitude nominally between 0 and 1 |
Related components:
Example DrawingBoards illustrating usage:
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