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admb_real:sdreport_and_vpa [2010/09/17 11:45] lennartfradmb_real:sdreport_and_vpa [2010/09/20 07:27] (current) lennartfr
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 +===== Comparison of models with VPA =====
 +
 The purpose of this section is to compare the estimates from our model, with those of the ICES VPA models. The purpose of this section is to compare the estimates from our model, with those of the ICES VPA models.
  
 +:!: The model with the lowest objective function value, and hence the best fit, is the model with [[admb_real:sdreport_and_vpa#model_with_two_catchabilities|two catchabilities.]]
 ==== VPA trajectories and confidence intervals for the estimated population trajectories ==== ==== VPA trajectories and confidence intervals for the estimated population trajectories ====
  
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 |{{:admb_real:survey_84_90.png?180|}} |{{:admb_real:survey_91_97.png?180|}} |{{:admb_real:survey_98_04.png?180|}} |{{:admb_real:survey_05_07.png?180|}} | |{{:admb_real:survey_84_90.png?180|}} |{{:admb_real:survey_91_97.png?180|}} |{{:admb_real:survey_98_04.png?180|}} |{{:admb_real:survey_05_07.png?180|}} |
  
-As can be seen, the cohorts born in 1994 to 1997 seem to be the strongest. Also, the curves are not monotoic, with the curve for the cohort born 1988 having a particularly challenging shape. This should be taken into consideration when designing the model.+As can be seen, the cohorts born in 1994 to 1997 seem to be the strongest. Also, the curves are not monotonic, with the curve for the cohort born 1988 having a particularly challenging shape. This should be taken into consideration when designing the model.
  
 ==== Simple model ==== ==== Simple model ====
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 # Mvec: # Mvec:
  0.200080104295  0.200080104295
-</file>+</file> |
  
 :!: M is at its upper bound, and q is at its lower bound, giving enourmous estimates for N0. :!: M is at its upper bound, and q is at its lower bound, giving enourmous estimates for N0.
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 Once again the mortality is at its upper bound. The confidence intervals for ages 0-2 are huge, but all the VPA estimates starting at age 3 are within the confidence intervals of the model, which are much smaller for these ages. Once again the mortality is at its upper bound. The confidence intervals for ages 0-2 are huge, but all the VPA estimates starting at age 3 are within the confidence intervals of the model, which are much smaller for these ages.
 +
 +Since it in general seems to be very difficult to make inferences about 0-2 year olds, it could be worthwile to study the plot starting with the model's estimates for 3-year olds. This is shown in the following plot:
 +
 +{{:admb_real:cod_two_q_vs_vpa_94_97_matlab.png?200|}}
 +
 +:!: In this plot, the //dotted// lines plus **solid** error bars are the model's estimates. The **solid** lines are the VPA estimates.
  
 ==== Model with two mortality parameters and two catchabilities ==== ==== Model with two mortality parameters and two catchabilities ====
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 The results on the cohorts born 1994-1997 are: The results on the cohorts born 1994-1997 are:
 +|{{:admb_real:cod_two_q_two_m_vs_vpa_94_97.png?180|}} |<file txt cod.par># Number of parameters = 8  Objective function value = -8.87586  Maximum gradient component = 7.41794e-05
 +# N0:
 + 14.6581 23.0200 22.4038 24.6862
 +# q02:
 + 0.0959335
 +# q3plus:
 + 0.0500000
 +# logs:
 +-0.785191293861
 +# M:
 +0.462069471505
 +# Mvec:
 + 0.186827045052
 +</file> |
  
 +:!: Once again q is at its lower bound, resulting in enourmous estimates for N0.
admb_real/sdreport_and_vpa.1284723932.txt.gz · Last modified: 2010/09/17 11:45 by lennartfr