larch.model.mixtures.NegLogNormal#

class NegLogNormal(mean: str, std: str)[source]#

Bases: Normal

The negative of a log-normal distribution applied to a model parameter.

This is convenient when it is desired to ensure the parameter must be negative, as expected for coefficients associated with travel time or travel costs.

The “mean” and “std” parameters are the mean and standard deviation of the underlying normal distribution, not the mean and standard deviation of the log-normal distribution.

__init__(mean: str, std: str)#

Methods

__init__(mean, std)

param_names()

Named parameters referenced by this mixture, and their default values.

prep(bucket)

roll(draw_vec, parameters)

Apply this mixing distribution to some random draws.

to_dict()