Hi Irini
a piecewise linear specification is not difficult to specify. I am happy to help you but it would probably be easiest if you wrote down your specification for me and I'll show you how to do it in Apollo. The mlogit code isn't really helping me as I don't use mlogit
Stephane
Important: Read this before posting to this forum
- This forum is for questions related to the use of Apollo. We will answer some general choice modelling questions too, where appropriate, and time permitting. We cannot answer questions about how to estimate choice models with other software packages.
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Search found 1046 matches
- 02 Aug 2020, 16:42
- Forum: Model specification
- Topic: Log-transformation with a piecewise linearization
- Replies: 4
- Views: 5960
- 02 Aug 2020, 16:42
- Forum: Model specification
- Topic: Log-transformation with a piecewise linearization
- Replies: 4
- Views: 5960
Re: Log-transformation with a piecewise linearization
Hi Irini
a piecewise linear specification is not difficult to specify. I am happy to help you but it would probably be easiest if you wrote down your specification for me and I'll show you how to do it in Apollo. The mlogit code isn't really helping me as I don't use mlogit
Stephane
a piecewise linear specification is not difficult to specify. I am happy to help you but it would probably be easiest if you wrote down your specification for me and I'll show you how to do it in Apollo. The mlogit code isn't really helping me as I don't use mlogit
Stephane
- 26 Jul 2020, 09:41
- Forum: Post-estimation analysis/use of results
- Topic: prediction at individual level
- Replies: 10
- Views: 13583
Re: prediction at individual level
Hi Xian the function apollo_prediction returns the predictions at the level of individual observations, so it should be exactly what you're wanting.The list returned by apollo_prediction contains a column called chosen. You can also after estimation make the following call which will give you the li...
- 24 Jul 2020, 13:24
- Forum: Model specification
- Topic: Simultaneous estimation of parameters with potentially different scale
- Replies: 10
- Views: 17101
Re: Simultaneous estimation of parameters with potentially different scale
Yes, you have to: Let's say you have: V[['alt1']] = scale_base*Certain*(asc + cost_B*Cost1 + torsk_B*KT1 + laks_B*VL1 + bunn_B*HB1 + land_B*KL1)+ scale_treat*(1-Certain)*(cost_T*Cost1 + torsk_T*KT1 + laks_T*VL1 + bunn_T*HB1 + land_T*KL1) then the marginal impact of Cost1 on the utility is given by t...
- 24 Jul 2020, 09:03
- Forum: Model specification
- Topic: Simultaneous estimation of parameters with potentially different scale
- Replies: 10
- Views: 17101
Re: Simultaneous estimation of parameters with potentially different scale
The ASC could take that role for a start. You just use scale_treat. scale_treat/scale_base is going to be the same anyway as you must fix scale_base to 1. Then once you have estimated this first model, you can see whether some of the other betas should be the same between groups by conducting statis...
- 23 Jul 2020, 23:29
- Forum: Model specification
- Topic: Simultaneous estimation of parameters with potentially different scale
- Replies: 10
- Views: 17101
Re: Simultaneous estimation of parameters with potentially different scale
No. You need to fix the scale parameter for one sample to 1 anyway. But you also need to keep one parameter generic across the two samples. Think about it this way: - You have 5 attributes that you're estimating beta parameters for in your data - If you split your data into two groups, then you can ...
- 23 Jul 2020, 15:48
- Forum: Model specification
- Topic: ICLV
- Replies: 3
- Views: 5272
Re: ICLV
Hi
when the outcome is just a yes/no answer, and the attributes are situation rather than alternative specific, then you just make the utility 0 for one of the two alternatives, and put the attributes in the other utility. Only differences in utility matter
Hope that helps
Stephane
when the outcome is just a yes/no answer, and the attributes are situation rather than alternative specific, then you just make the utility 0 for one of the two alternatives, and put the attributes in the other utility. Only differences in utility matter
Hope that helps
Stephane
- 23 Jul 2020, 15:27
- Forum: Model specification
- Topic: Simultaneous estimation of parameters with potentially different scale
- Replies: 10
- Views: 17101
Re: Simultaneous estimation of parameters with potentially different scale
Hi
in order to estimate scale differences, at least one of the parameters needs to be shared between the samples. That's not the case in your specification, so your model is overspecified
NB. You're also missing the ASC for the second group, but maybe this was intentional
Best wishes
Stephane
in order to estimate scale differences, at least one of the parameters needs to be shared between the samples. That's not the case in your specification, so your model is overspecified
NB. You're also missing the ASC for the second group, but maybe this was intentional
Best wishes
Stephane
- 23 Jul 2020, 15:24
- Forum: Model specification
- Topic: ICLV
- Replies: 3
- Views: 5272
Re: ICLV
Hi
it's difficult to offer general help without specific questions or issues. Did you look at the ICLV examples on the website?
Best wishes
Stephane
it's difficult to offer general help without specific questions or issues. Did you look at the ICLV examples on the website?
Best wishes
Stephane
- 20 Jul 2020, 14:36
- Forum: Bug reports
- Topic: Problems with multi-core in R4.x
- Replies: 1
- Views: 5968
Re: Problems with multi-core in R4.x
Hi Yishih Thanks for bringing this issue to our attention. This is indeed a wider RStudio issue rather than an Apollo issue. We have implemented a fix in v0.1.1 that creates the cores sequentially on MacOS systems. It adds a small additional setup time in creating the cores but has no impact on run ...