pastas.rfunc.Gamma#

class pastas.rfunc.Gamma(cutoff: float = 0.999, **kwargs)#

Gamma response function with 3 parameters A, a, and n.

Parameters:

  • up (bool or None, optional) – indicates whether a positive stress will cause the head to go up (True, default) or down (False), if None the head can go both ways.

  • gain_scale_factor (float, optional) – mean value of the stress, used to set the initial value such that the final step times the mean stress equals 1.

  • cutoff (float, optional) – proportion after which the step function is cut off.

Notes

The impulse response function for this class can be viewed on the Documentation website or using latexify by running the following code in a Jupyter notebook environment:

ps.Gamma.impulse

The Gamma function is equal to the Exponential function when n=1.

Methods#

get_init_parameters(→ pandas.DataFrame)

Get initial parameters and bounds. It is called by the stressmodel.

get_tmax(→ float)

Method to get the response time for a certain cutoff.

step(→ pastas.typing.ArrayLike)

Method to return the step function.

moment(→ float)

Compute the raw moment of the response function.

impulse(→ pastas.typing.ArrayLike)

Method to return the impulse response function.