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--- admb_real:sdreport_and_vpa [2010/09/17 11:24] – lennartfr
+++ admb_real:sdreport_and_vpa [2010/09/20 07:27] (current) – lennartfr
@@ Line 1: / Line 1: @@
+===== 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 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 ====
@@ Line 13: / Line 16: @@
 |{{: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 ====
@@ Line 41: / Line 44: @@
 This model has a different mortality for ages seven and up, and is defined [[admb_real:admb_real#model_with_two_mortality_parameters|here.]]
+The results on the cohorts born 1994-1997 are:
+|{{:admb_real:cod_two_m_vs_vpa_94_97.png?180|}} | <file txt cod.par># Number of parameters = 7  Objective function value = -5.31648  Maximum gradient component = 7.02229e-05
+# N0:
+.5376 32.1456 31.1941 34.5743
+# q:
+.0500000
+# logs:
+-0.684744666960
+# M:
+.500000000000
+# Mvec:
+.200080104295
+</file> |
+:!: M is at its upper bound, and q is at its lower bound, giving enourmous estimates for N0.
 ==== Model with two catchabilities ====
+This model has a separate catchability for ages 3 and up, and is defined [[admb_real:admb_real#model_with_two_separate_catchabilities|here.]]
+The results on the cohorts born 1994-1997 are:
+|{{:admb_real:cod_two_q_vs_vpa_94_97.png?180|}} |<file txt cod.par># Number of parameters = 8  Objective function value = -9.71777  Maximum gradient component = 2.08793e-05
+# N0:
+.43390 13.5985 13.6065 14.4040
+# q02:
+.172378
+# q3plus:
+.0982044
+# logs:
+-0.769938145537
+# M:
+.499999811181
+</file>|
+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 ====
+This model is the combination of the two preceding models. It is defined [[admb_real:admb_real#model_with_two_separate_catchabilities_and_two_mortalities|here.]]
+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:
+.6581 23.0200 22.4038 24.6862
+# q02:
+.0959335
+# q3plus:
+.0500000
+# logs:
+-0.785191293861
+# M:
+.462069471505
+# Mvec:
+.186827045052
+</file> |
+:!: Once again q is at its lower bound, resulting in enourmous estimates for N0.