I'm getting an error when trying to develop an availability design
[Modified Fedorov] ERROR: The candidate set of the Modified Fedorov algorithm is smaller than the number of rows specified. That is, there are not enough unique choice sets to generate the number required as specificed in the ;rows property. This problem sometimes appears when there are too many reject and/or reject constraints.
1- I developped a factorial design without any constraints
- Code: Select all
Design
;alts = hotelA*, hotelB*, hotelC*, None
;rows = 7200
;fact
;model:
U(hotelA) = b1 * price[100,125,150,175,200] + b2 * stars[1,3,5] + b3 * distance[5,10,15] +
b4 * wifi[0,1] + b5 * breakfast[0,1] + b6 * pool[0,1] /
U(hotelB) = b1 * price + b2 * stars + b3 * distance + b4 * wifi + b5 * breakfast + b6 * pool /
U(hotelC) = b1 * price + b2 * stars + b3 * distance + b4 * wifi + b5 * breakfast + b6 * pool
$
The 7200 choice sets had been copied into an excel file. Then, I selected randomly some choicesituations where hotelA is unavailable (all code are 999 or -999)
and then I used the following code
- Code: Select all
Design
;alts = hotelA*, hotelB*, hotelC*, None
;rows = 240
;block = 20
;eff = (mnl,d)
;alg = mfederov(candidates = D:\Naji\All_I_Know\ConjointAnalysis\availability.xlsx)
;model:
U(hotelA) = b1[-.01] * price[100,125,150,175,200,999] + b2[.1] * stars[1,3,5,-999] + b3[-.1] * distance[5,10,15,999] +
b4[.2] * wifi[0,1,-999] + b5[.2] * breakfast[0,1,-999] + b6[.2] * pool[0,1,-999] /
U(hotelB) = b1 * price + b2 * stars + b3 * distance + b4 * wifi + b5 * breakfast + b6 * pool /
U(hotelC) = b1 * price + b2 * stars + b3 * distance + b4 * wifi + b5 * breakfast + b6 * pool
$
It happened whatever the propension of hotelA's availability choice situations -in excel- (10% vs 50% vs 90%)
Additionnal question I would like to add in U(hotelB) & U(hotelC) the cross effect of A unavailability
Thanks for your help
Nassar