Slew-Rate Limiting

The signal samples of a signal trace can be processed with a linear slew-rate limiting algorithm.

Limiting Slew-Rates

You can limit the positive and negative slew-rate of the signal samples by calling the method ramp(), and providing the maximal allowed positive and negative delta limits between consecutive samples.

A new Trace instance labeled with the performed transformation 'ramp' is returned.

>>> # slew-rate of the signal samples limited by numbers
>>> Trace('Signal', [-1, 1, 1, 1, 1, -1, -1, -1, -1]).ramp(limits=(0.5, -0.5))
Trace(label='Signal:ramp', samples=[-1, -0.5, 0.0, 0.5, 1, 0.5, 0.0, -0.5, -1])

>>> # slew-rate of the signal samples limited by traces
>>> Trace('Signal', [0, 1, -1, 1, -1, 1, -1, 1, 0]).ramp(
...   limits=(Trace('Positive Limit',
...                  [0.25, 0.25, 0.5, 0.5, 0.75, 0.75, 1.0, 1.0, 0]),
...           Trace('Negative Limit',
...                  [0, 0, -1.0, -1.0, -0.75, -0.75, -0.5, -0.5, -0.25])))
Trace(label='Signal:ramp', samples=[0, 0.25, -0.75, -0.25, -1, -0.25, -0.75, 0.25, 0])

>>> # slew-rate of the signal samples limited by iterables
>>> Trace('Signal', [0, 1, -1, 1, -1, 1, -1, 1, 0]).ramp(
...   limits=(
...     [0.25, 0.25, 0.5, 0.5, 0.75, 0.75, 1.0, 1.0, 0],
...     [0, 0, -1.0, -1.0, -0.75, -0.75, -0.5, -0.5, -0.25]))
Trace(label='Signal:ramp', samples=[0, 0.25, -0.75, -0.25, -1, -0.25, -0.75, 0.25, 0])

Note

An iterable limit should have at least the same length as the signal samples, otherwise only a subset of the signal samples is returned!

(Source code, html)

Limiting Positive Slew-Rate

You can limit the positive slew-rate of the signal samples by calling the method ramp(), and providing the maximal allowed positive delta limits between consecutive samples.

A new Trace instance labeled with the performed transformation 'ramp' is returned.

>>> # positive slew-rate of the signal samples limited by a number
>>> Trace('Signal', [0, -1, 1, 1, 1, 1, 1, 0, -1]).ramp(limits=(0.5, None))
Trace(label='Signal:ramp', samples=[0, -1, -0.5, 0.0, 0.5, 1, 1, 0, -1])

>>> # positive slew-rate of the signal samples limited by a trace
>>> Trace('Signal', [0, -1, 1, 1, 1, 1, 1, 0, -1]).ramp(
...   limits=(Trace('Positive Limit',
...                 [0, 0, 0.25, 0.5, 0, 0.75, 0.5, 0, 0]), None))
Trace(label='Signal:ramp', samples=[0, -1, -0.75, -0.25, -0.25, 0.5, 1, 0, -1])

>>> # positive slew-rate of the signal samples limited by an iterable
>>> Trace('Signal', [0, -1, 1, 1, 1, 1, 1, 0, -1]).ramp(
...   limits=([0, 0, 0.25, 0.5, 0, 0.75, 0.5, 0, 0], None))
Trace(label='Signal:ramp', samples=[0, -1, -0.75, -0.25, -0.25, 0.5, 1, 0, -1])

Note

An iterable limit should have at least the same length as the signal samples, otherwise only a subset of the signal samples is returned!

(Source code, html)

Limiting Negative Slew-Rate

You can limit the negative slew-rate of the signal samples by calling the method ramp(), and providing the maximal allowed negative delta limits between consecutive samples.

A new Trace instance labeled with the performed transformation 'ramp' is returned.

>>> # negative slew-rate of the signal samples limited by a number
>>> Trace('Signal', [0, 1, -1, -1, -1, -1, -1, 0, 1]).ramp(limits=(None, -0.5))
Trace(label='Signal:ramp', samples=[0, 1, 0.5, 0.0, -0.5, -1, -1, 0, 1])

>>> # negative slew-rate of the signal samples limited by a trace
>>> Trace('Signal', [0, 1, -1, -1, -1, -1, -1, 0, 1]).ramp(
...   limits=(None, Trace('Negative Limit',
...                       [0, 0, -0.25, -0.5, 0, -0.75, -0.5, 0, 0])))
Trace(label='Signal:ramp', samples=[0, 1, 0.75, 0.25, 0.25, -0.5, -1, 0, 1])

>>> # negative slew-rate of the signal samples limited by an iterable
>>> Trace('Signal', [0, 1, -1, -1, -1, -1, -1, 0, 1]).ramp(
...   limits=(None, [0, 0, -0.25, -0.5, 0, -0.75, -0.5, 0, 0]))
Trace(label='Signal:ramp', samples=[0, 1, 0.75, 0.25, 0.25, -0.5, -1, 0, 1])

Note

An iterable limit should have at least the same length as the signal samples, otherwise only a subset of the signal samples is returned!

(Source code, html)