ESURGE GEMACO age coding question

questions concerning analysis/theory using programs M-SURGE, E-SURGE and U-CARE

ESURGE GEMACO age coding question

Postby Super » Mon Jan 09, 2012 4:32 pm

I have a question about the GEMACO coding for ages when individuals of different ages are present at the first marking occasion. The ESURGE manual gives an example of how to do this for two “marking groups” (e.g. when there are juveniles (1yo) and adults (2+yo) present at the first occasion). In this case the GEMACO shortcut for Juveniles is [a(1).g(1)] and for the Adults for [a(2 : last age).g(1)&g(2)]. And then the shortcut for “RealAge” would be [Juveniles + Adults]

When I do this and set Transition ~ RealAge I get two parameters for the two age groups – as expected. All good.
F To T A G S
Beta #1 1 1 1 1 2 1
Beta #2 1 1 1 1 1 1

But the parameterisation with 3 ages (and 3 marking groups) seems to be different.
Three marking groups: g(1) = marked as Adults; g(2) = marked as Juveniles; g(3) = marked as Older (they’re in alphabetical order )
Maximum number of age classes = 3.
GEMACO code is:
Juvs = [a(1).g(2)]
Ads = [a(2).g(2)& a(1).g(1)]
Olds = [a(3).g(2)& a(2:3).g(2)&g(3)]
RealAge= [Juvs+Ads+Olds]

The difference is that when I set Transition ~ RealAge I get three parameters but two of these are different groups (the Juvs and Ads) and the third is an “age” parameter at the second time period rather than a third age group.
F To T A G S
Beta #1 1 1 1 1 2 1
Beta #2 1 1 1 1 1 1
Beta #3 1 1 2 2 1 1

And when I look at the output from the model with Transition ~ [RealAge + t] for my dataset (which has 5 time intervals) I get 9 parameters associated with group 1 (five of which are for age 1, and four of which are age 2 from time 2) then five parameters for group 2, then a single parameter for group 3.

Params From To Time Age Group Step Estimates
Surv 1 1 1 1 1 1 0.729
Surv 1 1 2 1 1 1 0.921
Surv 1 1 3 1 1 1 0.417
Surv 1 1 4 1 1 1 0.467
Surv 1 1 5 1 1 1 0.268
Surv 1 1 2 2 1 1 0.859
Surv 1 1 3 2 1 1 0.273
Surv 1 1 4 2 1 1 0.315
Surv 1 1 5 2 1 1 0.161
Surv 1 1 1 1 2 1 0.709
Surv 1 1 2 1 2 1 0.913
Surv 1 1 3 1 2 1 0.393
Surv 1 1 4 1 2 1 0.443
Surv 1 1 5 1 2 1 0.248
Surv 1 1 1 1 3 1 0.586

Is this ok? Or have I done something wrong?
Which group is which? (e.g. Is Group 1 made of Ads & Olds? )
Can I assume that the single parameter for group 3 at time 1 is the ‘missing’ estimate at the first time period from Age 2/Group 1?
Super
 
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Joined: Fri Jan 06, 2012 7:36 am

Re: ESURGE GEMACO age coding question

Postby CHOQUET » Tue Jan 10, 2012 5:11 am

Hello,
I think that there is a little mistake, instead of

GEMACO code is:
Juvs = [a(1).g(2)]
Ads = [a(2).g(2)& a(1).g(1)]
Olds = [a(3).g(2)& a(2:3).g(2)&g(3)]
RealAge= [Juvs+Ads+Olds]

change Olds to :

Olds = [a(3).g(2)& a(2:3).g(1)&g(3)]

Rémi
CHOQUET
 
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Location: CEFE, Montpellier, FRANCE.

Re: ESURGE GEMACO age coding question

Postby Super » Tue Jan 10, 2012 5:44 am

Thank you for the promt reply Remi - you are right the code should like this
Juvs = [a(1).g(2)]
Ads = [a(2).g(2)& a(1).g(1)]
Olds = [a(3).g(2)& a(2:3).g(1)&g(3)]
RealAge= [Juvs+Ads+Olds]

but this was just a typo mistake in my question. I actually did use this code for the ages..so the problem still stands..
any advice?
Super
 
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Joined: Fri Jan 06, 2012 7:36 am

Re: ESURGE GEMACO age coding question

Postby CHOQUET » Wed Jan 11, 2012 10:33 am

I think that all is correct. See above that all parameters for realage(denoted a)
1,2 and 3 and for all occasions are given.

Params From To Time Age Group Step Estimates
Surv 1 1 1 1 1 1 0.729 a(2) t(1)
Surv 1 1 2 1 1 1 0.921 a(2) t(2)
Surv 1 1 3 1 1 1 0.417 a(2) t(3)
Surv 1 1 4 1 1 1 0.467 a(2) t(4)
Surv 1 1 5 1 1 1 0.268 a(2) t(5)

Surv 1 1 2 2 1 1 0.859 a(3) t(2)
Surv 1 1 3 2 1 1 0.273 a(3) t(3)
Surv 1 1 4 2 1 1 0.315 a(3) t(4)
Surv 1 1 5 2 1 1 0.161 a(3) t(5)

Surv 1 1 1 1 2 1 0.709 a(1) t(1)
Surv 1 1 2 1 2 1 0.913 a(1) t(2)
Surv 1 1 3 1 2 1 0.393 a(1) t(3)
Surv 1 1 4 1 2 1 0.443 a(1) t(4)
Surv 1 1 5 1 2 1 0.248 a(1) t(5)

Surv 1 1 1 1 3 1 0.586 a(3) t(1)
CHOQUET
 
Posts: 211
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Location: CEFE, Montpellier, FRANCE.

Re: ESURGE GEMACO age coding question

Postby Super » Thu Jan 12, 2012 4:28 am

Thank you for clarifying this. I thought this was how I should interpret the output, but was unsure due to the seemingly strange combination of realage/age groupings, and just wanted to check that I had it right.
Super
 
Posts: 3
Joined: Fri Jan 06, 2012 7:36 am


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