[R] How to use depmix for HMM with intial parameters

Ismail SEZEN sezenismail at gmail.com
Wed Sep 20 17:19:11 CEST 2017


> On 20 Sep 2017, at 11:14, niharika singhal <niharikasinghal1990 at gmail.com> wrote:
> 
> Hello,
> 
> I have initial parameters for HMM model and I want to use depmixS4 package.
> The parameters are in the form
> 
> intial_prob_matrix=matrix(c(0.07614213, 0.45177665, 0.47208122), nrow=1,
> ncol=3, byrow = TRUE)
> 
> transition_matrix=matrix(c(0.46666667,0.46666667,0.06666667,
>                     0.06741573,0.5617978,0.37078652,
>                     0.02173913,0.3478261,0.63043478), nrow = 3, ncol = 3,
> byrow = TRUE)
> 
> meanval_matrix=matrix(c(545.1737,545.1737,803.5235,
>                        565.7763,673.8019,797.5283,
>                        733.9332,1006.3571,1383.5395), nrow = 3, ncol = 3,
> byrow = TRUE)
> 
> sigmaval_matrix=matrix(c(82.19592,13.64243,57.07868,
>                         65.32724,13.38910,81.66209,
>                         97.62573,71.09579,115.55612), nrow = 3, ncol = 3,
> byrow = TRUE)
> 
> coeffval_matrix=matrix(c(0.1295604,0.6464059,0.2240336,
>                         0.2091671,0.5267220,0.2641110,
>                         0.3430697,0.3350215,0.3219088), nrow = 3, ncol =
> 3, byrow = TRUE)
> 
> emission_matrix=list(meanval_matrix,sigmaval_matrix,coeffval_matrix)
> 
> powerdf is a column from my dataset which look like something = 19.0, 18.0,
> 24.0...............it has some 30 thousand rows
> 
> I tried  using the code below and got an error
> 
> mod= depmix( response = power~1, data = powerdf, nstates=3,
>                           instart=intial_prob_matrix,
> trstart=transition_matrix, respstart=emission_matrix)
> 
> Error in makeResponseModels(response = response, data = data, nstates =
> nstates,  :
>  'respstart' has incorrect length, it should be 6
> 
> I cannot change my emission matrix, it would always be list of matrix (mean
> , sigma and weighted coefficient mixture)
> 
> I thought to change the response but I am unable to figure out the right
> response
> 
> Can someone guide me how can I solve this problem, by giving the
> parameters defined above?
> 
> Thanks & Regards
> Niharika Singhal

Hello Niharika,

As this is a very specific statistical question, you also should ask this kind of a question at [1]. You may get faster response.

1- https://stats.stackexchange.com



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