I have 20 occasions, 19 ages, 4 events, 3 states and 1 groups. States are non-breeding (NB), breeding (B) and dead (D). Events are not-detected (ND), NB, B, and unknown (UN). Without an external covariate the following model works perfectly:
GEPAT:
Initial state:
- Code: Select all
1 2
1 * p
Transition step 1: Survival
- Code: Select all
1 2 3
1 f - *
2 - f *
3 - - *
Transition step 2: Transition
- Code: Select all
1 2 3
1 * y -
2 y * -
3 - - *
Event step 1: Detection
- Code: Select all
1 2 3
1 * b -
2 * - b
3 * - -
Event step 2: Uncertainty
- Code: Select all
1 2 3 4
1 * - - -
2 - * - d
3 - - * d
GEMACO:
IS: to
T1: from
T2: from.t
E1: firste+nexte.from.t
E2: from
Initial value of 'firste' is fixed at 1.
My external covariate file 'Effort.txt' is in the appropriate format as described in the Manual v1.8, and the same format as other external covariate files I have from tutorial courses which work:
__
1
20
33 97 122 81 28 53 54 86 123 96 136 134 111 139 122 145 156 186 183 243
__
For GEMACO E1 I would expect that the correct phrase to allow detection probability to vary according to survey effort at each time occasion, with different detection probabilities of NB and B states would be:
firste+nexte.from.[i+t*x(1)]
But this doesn't work? I've tried many other formulations but without success. I also tried putting just the last 19 occasions in the effort file, because for time = 1 all are first captures, so nexte in interaction with time might only be estimating 19 occasions? Can somebody see what I would need to do differently, or what the correct approach is?
Thanks in advance