bioLogLogit expression

[Fani Hatziioannidu]

Dear Professor, dear Modellers,

I am trying to estimate a mode choice model with frequencies or aggregated responses instead of individual choices in the data set.

For aggregate data I have multiplied the contribution to the loglikelihood for each alternative by the number of times it is chosen,

after the advice of Professor Bierlaire as follows:

logprob = nbr_alt_1 * bioLogLogit(V,av,1) + nbr_alt_2 * bioLogLogit(V,av,2)  + … + nbr_alt_J * bioLogLogit(V,av,J) 

I have also upgraded to the latest version of Pandas for Windows.

I get the error message that

name 'bioLogLogit' is not defined

or if I add in the begging of the code:

from biogeme.expressions import bioLogLogit, Beta

I get the error message

cannot import name 'bioLogLogit' from 'biogeme.expressions' (C:\...\Anaconda3\lib\site-packages\biogeme\expressions.py)

Could you please advice me of what is the correct syntax or how to solve this?

kind regards,

Fani Hatziioannidu