logit.py

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from biogeme import *


def logit_av_scale(V,availability,choice,group,scale):
    s = Elem(scale,group)
    scaledV = {}
    availBinary = {}
    for k,v in V.items() :
        availBinary[k] = int(availability[k] != 0)
        scaledV[k] = s * v
    P = bioLogit(scaledV,availability,choice) 
    return P


def logit(V,choice) :
    avail = {}
    for k,v in V.items() :
        avail[k] = 1 
    P = bioLogit(V,avail,choice)
    return P


def logit_scale(V,choice,group,scale) :
    s = Elem(scale,group)
    chosen = Elem(V,choice)
    den = 0
    for i,v in V.items() :
        den += exp(s * (v-chosen))
    P = 1.0 / den 
    return P