1  Introduction

Bridging the Gulf of Alaska northern rockfish model from ADMB to RTMB. The ADMB program is in the process of an ‘orderly shutdown of development’ (see: ADMB) and TMB is a viable alternative for fishery stock assesment development. RTMB allows for using the native R interface to TMB (Template Model Builder) so models can be written entirely in R rather than C++ (Kristensen 2024).

To compare model outputs last full model accepted by the SSC for northern rockfish ADMB model 22.1 was evaluated. The ADMB code was transferred to RTMB code. Then the model was run using the parameter outputs from the ADMB model, direct differences between model outputs and percent difference of key components are presented.

All associated code is available

Kristensen, Kasper. 2024. RTMB: ’R’ Bindings for ’TMB’. https://github.com/kaskr/rtmb.