braintools.input.sawtooth

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braintools.input.sawtooth#

braintools.input.sawtooth(amplitude, frequency, duration, t_start=None, t_end=None, bias=False)#

Generate sawtooth wave current input.

Creates a sawtooth waveform that ramps up linearly and then drops sharply. Useful for testing reset dynamics, asymmetric responses, and ramp sensitivity.

Parameters:

  • amplitude (Array | ndarray | bool | number | bool | int | float | complex | Quantity) – Peak amplitude of the sawtooth wave. Supports current units.

  • frequency (Array | ndarray | bool | number | bool | int | float | complex | Quantity) – Frequency of oscillation. Must be in Hz units.

  • duration (Array | ndarray | bool | number | bool | int | float | complex | Quantity) – Total duration of the signal. Supports time units.

  • t_start (Array | ndarray | bool | number | bool | int | float | complex | Quantity | None) – Time when sawtooth wave starts. Before this, output is 0. Default is 0.

  • t_end (Array | ndarray | bool | number | bool | int | float | complex | Quantity | None) – Time when sawtooth wave ends. After this, output is 0. Default is duration.

  • bias (bool) – If True, adds DC offset equal to amplitude (non-negative output). If False, ramps from -amplitude to +amplitude.

Returns:

current – The sawtooth wave current array with shape (n_timesteps,).

Return type:

ndarray or Quantity

Raises:

AssertionError – If frequency is not in Hz units.

Examples

>>> import brainunit as u
>>> import brainstate
>>> brainstate.environ.set(dt=0.1 * u.ms)

Simple sawtooth at 2 Hz

>>> current = sawtooth(
...     amplitude=10 * u.pA,
...     frequency=2 * u.Hz,
...     duration=2000 * u.ms
... )

Slow ramp for threshold detection

>>> current = sawtooth(
...     amplitude=50 * u.pA,
...     frequency=0.5 * u.Hz,  # 2 second ramp
...     duration=4000 * u.ms
... )

Sawtooth with positive bias

>>> current = sawtooth(
...     amplitude=5 * u.nA,
...     frequency=10 * u.Hz,
...     duration=500 * u.ms,
...     bias=True  # Ramps from 0 to 10 nA
... )

Windowed sawtooth stimulation

>>> current = sawtooth(
...     amplitude=8 * u.pA,
...     frequency=5 * u.Hz,
...     duration=2000 * u.ms,
...     t_start=400 * u.ms,
...     t_end=1600 * u.ms
... )

Fast sawtooth for reset testing

>>> current = sawtooth(
...     amplitude=20 * u.pA,
...     frequency=20 * u.Hz,
...     duration=250 * u.ms
... )

Repeated ramp protocol

>>> current = sawtooth(
...     amplitude=100 * u.pA,
...     frequency=1 * u.Hz,
...     duration=10000 * u.ms
... )

Notes

  • Ramps linearly from -amplitude to +amplitude, then resets

  • With bias=True, ramps from 0 to 2*amplitude

  • The ramp is continuous, reset is instantaneous

  • Useful for finding thresholds and testing reset mechanisms

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