irt-service/app/lib/irt/models/three_parameter_logistic.py

14 lines
395 B
Python

class ThreeParameterLogistic:
def __init__(self, model_params, kwargs):
self.model_params = model_params
# check if exists, if not error out
self.b_param = kwargs['b_param']
self.e = 2.71828
self.theta = kwargs['theta']
def result(self):
a = self.model_params.a
c = self.model_params.c
return c + (1 - c) * (1 / (1 + e**(-a * (self.theta - self.b_param))))