Nuts and bolts description of Recap
Recap is a Mathematica-based program to evaluate the uncertainty of the yearly Russian-Norwegian September survey of capelin by resampling the input data The program works in the following steps:
1 Reading and internal organising of data
2 Grouping biological samples to WMO squares
3 Grouping Sa-values to WMO squares
4 Calculating mean Sa value by square and constructing an internal working list of data (areasampleInteg) for each square
5 Calculating number at length in each square
6 Calculating number at length, age and sex on the larger Multspec areas
This procedure follows closely what is done in the field program BEAM. The difference is primarily that biological samples are located automatically to WMO squares and Multspec areas, while in BEAM there is s subjective element in the allocation, based on the experience from the survey conducted. Also, in Recap the larger areas are the Multspec areas, which are fixed from year to year and therefore facilitates a comparison of geographical distribution. In BEAM the larger areas are made subjectively, from the observed geographical distribution of biological characteristics.
The aim of the present description is both to serve as a documentation of what the program does and as a guideline for people using, maintaining and developing the program.
The program can also be used for the winter capelin survey. In the code as well as in the documentation the word "Autumn" could then be substituted by the word "Winter".
It should be noted that it is not the intention to use results from Recap as an estimate of distribution on its own. Since in Recap much of the knowledge from the particular survey is missing or difficult to implement, Recap distribution must always be scaled with the point estimate from the survey.
If you are running in Mathematica 6 or later versions, windows for acoustic data and biological data are presented on which one may click on individual stations to get printed details of the observations.
View a map of WMO squares
View a map of Multspec areas
Stage 1 - Reading and internal organising of data
Stage 2 - Grouping biological samples to WMO squares
Stage 3 - Grouping Sa-values to WMO squares
Stage 4 - Calculating mean Sa-values by WMO squares, arranging data for final calculation of the estimate
Stage 5 - Calculating total number at length in WMO squares
Stage 6 - Calculating number at length age and sex on Multspec areas and in total
Using Recap
Special features
Created with Wolfram Mathematica 9.0