Channel Class
A Channel object describes a single channel from a CHOP. The CHOP Class provides many ways of accessing its individual channels. See Working with CHOPs in Python for more examples of how to use this class.
Members
valid → bool (Read Only):
True if the referenced chanel value currently exists, False if it has been deleted.
index → int (Read Only):
The numeric index of the channel.
name → str (Read Only):
The name of the channel.
owner → OP (Read Only):
The OP to which this object belongs.
exports → list (Read Only):
The (possibly empty) list of parameters this channel currently exports to.
vals → list :
Get or set the full list of Channel values. Modifying Channel values can only be done in Python within a Script CHOP.
Methods
[index]→ float:
Sample values may be easily accessed from a Channel using the [] subscript operator.
- index - Must be an numeric sample index. Wildcards are not supported.
To get the third sample from the channel, assuming the channel has 3 or more samples:
n = op('pattern1') c = n['chan1'][2] # the third sample l = len(n['chan2']) # the total number of samples in the channel
eval(index)→ float:
Evaluate the channel at the specified index sample index. If no index is given, the current index based on the current time is used.
- index - (Optional) The sample index to evaluate at.
evalFrame(frame)→ float:
Evaluate the channel at the specified frame. If no frame is given, the current frame is used.
- frame - (Optional) The frame to evaluate at.
evalSeconds(secs)→ float:
Evaluate the channel at the specified seconds. If no time is given, the current time is used.
- secs - (Optional) The time in seconds to evaluate at.
numpyArray()→ numpy.ndarray:
Returns this channels data as a NumPy array with a length equal to the track length.
destroy()→ None:
Destroy and remove the actual Channel this object refers to. This operation is only valid when the channel belongs to a Script CHOP or OSC In CHOP . Note: after this call, other existing Channel objects in this CHOP may no longer be valid.
average()→ float:
Returns the average value of all the channel samples.
min()→ float:
Returns the minimum value of all the channel samples.
max()→ float:
Returns the maximum value of all the channel samples.
copyNumpyArray(numpyArray)→ None:
Copies the contents of the numpyArray into the Channel sample values.
- numpyArray - The NumPy Array to copy. Must be shape(n), where n is the sample length of the CHOP. The data type must be float32. Modifying Channel values can only be done in Python within a Script CHOP.
Casting to a Value
The Channel Class implements all necessary methods to be treated as a number, which in this case evaluates its current value. Therefore, an explicit call to eval() is unnecessary when used in a parameter, or in a numeric expression.
For example, the following are equivalent in a channel:
(float)n['chan1']
n['chan1'].eval()
The following are also equivalent, because the + 1 will implicitly cast the channel to a number:
n['chan1'].eval() + 1
n['chan1'] + 1
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