pastas.rfunc.Polder

class pastas.rfunc.Polder(cutoff: float = 0.999, use_block: bool = True, **kwargs)

Polder function, using the standard A, a, b parameters.

Parameters:

• cutoff (float, optional) – Fraction of the step response after which the response is truncated. Default is 0.999.

• use_block (bool, optional) – Use the block response (rather than the impulse response) to simulate the effect of a stress. The block response approximates the stress as uniform during a time interval dt. When False, the impulse response is used which means that the the entire stress occurs midway the time interval dt. The impulse response is generally quicker to compute.

up

Whether a positive stress causes the head to go up (True), down (False), or either direction (None).

Type:

bool or None, optional

gain_scale_factor

Scale factor used to set the initial value and bounds of the gain parameter, computed as 1 / gain_scale_factor.

Type:

float, optional

Notes

The function is explained in Eq. 123.32 in Bruggeman [1999].

property nparam: int

Return number of parameters for the response function.

Returns:

Number of parameters (3 for Polder: A, a, b).

Return type:

int

Methods

get_init_parameters(→ pandas.DataFrame)	Get initial parameters and bounds for the Polder response function.
get_tmax(→ float)	Get response time for a certain cutoff for Polder response function.
gain(→ float)	Return the gain of the Polder response function.
step(→ pastas.typing.ArrayLike)	Return the step function for Polder response.
moment(→ float)	Calculate the moment of a certain order for the Polder response function.
impulse(→ pastas.typing.ArrayLike)	Return the impulse response function for Polder.
polder_function(→ float)	Polder function used in the step response calculation.