02-linear-ramp.py - Portamento, glissando, ramping.
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The SigTo object allows to create audio glissando between the
current value and the target value, within a user-defined time.
The target value can be a float or another PyoObject. A new ramp
is created everytime the target value changes.

Also:

The VarPort object acts similarly but works only with float and
can call a user-defined callback when the ramp reaches the target
value.

The PyoObject.set() method is another way create a ramp for any
given parameter that accept audio signal but is not already
controlled with a PyoObject.

.. code-block:: python

    from pyo import *
    
    s = Server().boot()
    
    # 2 seconds linear ramp starting at 0.0 and ending at 0.3.
    amp = SigTo(value=0.3, time=2.0, init=0.0)
    
    # Pick a new value four times per second.
    pick = Choice([200, 250, 300, 350, 400], freq=4)
    
    # Print the chosen frequency
    pp = Print(pick, method=1, message="Frequency")
    
    # Add a little portamento on an audio target and detune a second frequency.
    freq = SigTo(pick, time=0.01, mul=[1, 1.005])
    # Play with portamento time.
    freq.ctrl([SLMap(0, 0.25, "lin", "time", 0.01, dataOnly=True)])
    
    # Play a simple wave.
    sig = RCOsc(freq, sharp=0.7, mul=amp).out()
    
    s.gui(locals())