Standardising catch per unit effort attempts to distinguish changes in abundance from changes in fishing practice and sampling composition. `influ2` calculates how fitted explanatory terms, random effects, and spatial fields move a standardised index through time. All supported model backends return the same compact [influ_diag] object and use the same plots.
Start with [influ()], then inspect the result with [summary.influ_diag()] or [plot.influ_diag()].
References
Bentley, N., Kendrick, T. H., Starr, P. J., and Breen, P. A. (2012). Influence plots and metrics: tools for better understanding fisheries catch-per-unit-effort standardizations. ICES Journal of Marine Science, 69(1), 84–88. doi:10.1093/icesjms/fsr174 .