# Category Archives: Fisheries Science

## Age & Growth with R (Portland, Oregon)

I (and Northland alum Taylor Stewart) will be leading a continuing education course on using R for typical age and growth analyses as part of the national American Fisheries Society conference in Portland, OR. Here is the announcement on the conference webpage … Continue reading

## New Packages for Reading Data into R

Hadley Wickham has announced two new package for reading external data into R that will likely be of great interest to fisheries scientists. readr — Several new functions that replace the traditional read.csv() and read.table() (among others). Hadley’s announcement is here, … Continue reading

## Recruitment Chapter for IFAR

I have added a very rough draft of the Recruitment chapter to the Introduction to Fisheries Analysis with R (IFAR) page. This chapter is a complete re-working of the old Stock-Recruitment vignette and includes a section on fitting non-linear stock-recruitment … Continue reading

## Changes to Von B Growth Modeling in FSA

In previous versions of FSA, growthModelSim() was used to produce a scatterplot of length-age data with a von Bertalanffy model superimposed where the parameters of the model were linked to slider bars that allowed the model to be dynamically changed … Continue reading

## Mortality & Age Comparisons Chapters

Thanks to some very thoughtful reviews, I have dramatically updated the Mortality and Age Comparisons chapters in the Introduction to Fisheries Analysis with R book. Changes to the Age Comparisons chapter in particular resulted in major changes to the FSA … Continue reading

## Weight-Length & Condition Chapters Updated

Thanks to a couple of great reviews, I have updated the Weight-Length and Condition chapters of the forthcoming Introduction to Fisheries Analysis with R book. The suggestions resulted in some changes to the FSA package so you may want to … Continue reading

## Plotting Fundamentals Chapter

I have uploaded a draft of Chapter 3 — Plotting Fundamentals — for the Introduction to Fisheries Analyses with R (IFAR) book (note the new name). This chapter is meant to be a quick introduction to plotting in base R for plots … Continue reading

## Two New Cumulative Sum Functions

In this document on RPubs, I describe two functions in FSA for computing cumulative sums. The first is pcumsum() for computing the cumulative sum NOT including the current value and the second is rcumsum() for computing the “reverse” cumulative sum.

## Efficiently Adding Gabelhouse Lengths and Relative Weights to a data.frame (using dplyr)

In this post on RPubs, I demonstrate how to use new functions (psdAdd() and wrAdd()) in the FSA package, along with functions in the dplyr package, to efficiently add Gabelhouse length category and relative weight variables for all species in … Continue reading

## Changes to FSA — Size Structure

I have added a (very rough) first draft to the Size Structure chapter of the forthcoming Introductory Fisheries Science with R book on the book’s fishR webpage. Accompanying this chapter are major changes to all of the proportional size distribution … Continue reading