My dataset look like this
ID choice_situation Alternative Attr1 Attr2 Attr3 choice
ID_1 1 1 0 0 0 0
ID_1 1 2 1 1 0 1
ID_1 2 1 1 1 0 0
ID_1 2 2 1 1 1 1
ID_1 3 1 2 1 0 1
ID_1 3 2 3 1 0 0
ID_2 1 1 3 0 1 1
ID_2 1 2 0 0 0 0
ID_2 2 1 2 1 1 0
ID_2 2 2 2 1 1 1
ID_2 3 1 0 0 0 1
ID_2 3 2 0 0 1 0
.....
Every time I run the code of mlogit function
DCE_data<- mlogit.data(data=dataset, choice = "choice", shape = "long", alt.var = "Alternative", id.var = "ID") #ok
model<- mlogit(choice ~ Attr1 + Attr2 + Attr3 | 0, DCE_data)#error
I get the error below :
Error in dfidx(x, .idx, pkg = pkg) :
the two indexes don't define unique observations
The problem is from the transformed data : DCE_data ?
Thanks in advance!
For me your code works:
library(tidyverse)
df <- tibble::tribble(
~ID, ~choice_situation, ~Alternative, ~Attr1, ~Attr2, ~Attr3, ~choice,
"ID_1", 1L, 1L, 0L, 0L, 0L, 0L,
"ID_1", 1L, 2L, 1L, 1L, 0L, 1L,
"ID_1", 2L, 1L, 1L, 1L, 0L, 0L,
"ID_1", 2L, 2L, 1L, 1L, 1L, 1L,
"ID_1", 3L, 1L, 2L, 1L, 0L, 1L,
"ID_1", 3L, 2L, 3L, 1L, 0L, 0L,
"ID_2", 1L, 1L, 3L, 0L, 1L, 1L,
"ID_2", 1L, 2L, 0L, 0L, 0L, 0L,
"ID_2", 2L, 1L, 2L, 1L, 1L, 0L,
"ID_2", 2L, 2L, 2L, 1L, 1L, 1L,
"ID_2", 3L, 1L, 0L, 0L, 0L, 1L,
"ID_2", 3L, 2L, 0L, 0L, 1L, 0L
)
library(mlogit)
DCE_data<- mlogit.data(data=df, choice = "choice", shape = "long", alt.var = "Alternative", id.var = "ID") #ok
model<- mlogit(choice ~ Attr1 + Attr2 + Attr3 | 0, DCE_data)#error
summary(model)
> model
Call:
mlogit(formula = choice ~ Attr1 + Attr2 + Attr3 | 0, data = DCE_data, method = "nr")
Coefficients:
Attr1 Attr2 Attr3
0.34137 14.86152 0.39473