apollo_mnl_2 {apollo} | R Documentation |
Calculates probabilities of a multinomial logit model.
apollo_mnl_2(mnl_settings, functionality)
mnl_settings |
List of inputs of the MNL model. It should contain the following.
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functionality |
Character. Can take different values depending on desired output.
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The returned object depends on the value of argument functionality
as follows.
"estimate"
: vector/matrix/array. Returns the probabilities for the chosen alternative for each observation.
"prediction"
: List of vectors/matrices/arrays. Returns a list with the probabilities for all alternatives, with an extra element for the probability of the chosen alternative.
"validate"
: Same as "estimate"
, but it also runs a set of tests to validate the function inputs.
"zero_LL"
: vector/matrix/array. Returns the probability of the chosen alternative when all parameters are zero.
"conditionals"
: Same as "estimate"
"output"
: Same as "estimate"
but also writes summary of input data to internal Apollo log.
"raw"
: Same as "prediction"
### Load data data(apollo_modeChoiceData) database <- apollo_modeChoiceData rm(apollo_modeChoiceData) ### Parameters b = list(asc_1=0, asc_2=0, asc_3=0, asc_4=0, tt=0, tc=0, acc=0) ### List of utilities V = list() V[['car' ]] = b$asc_1 + b$tt*database$time_car + b$tc*database$cost_car V[['bus' ]] = b$asc_2 + b$tt*database$time_bus + b$tc*database$cost_bus + b$acc*database$access_bus V[['air' ]] = b$asc_3 + b$tt*database$time_air + b$tc*database$cost_air + b$acc*database$access_air V[['rail']] = b$asc_4 + b$tt*database$time_rail + b$tc*database$cost_rail + b$acc*database$access_rail ### MNL settings mnl_settings <- list( alternatives = c(car=1, bus=2, air=3, rail=4), avail = list(car=database$av_car, bus=database$av_bus, air=database$av_air, rail=database$av_rail), choiceVar = database$choice, V = V ) ### Compute choice probabilities using MNL model apollo_mnl(mnl_settings, functionality="estimate")