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Hello,
I am using the resample library with angler catch rate data. Each row in the data table represents information from one fishing trip. The formula used to calculate the catch rate is the sum of all fish caught divided by the total number of hours spent fishing. I am bootstrapping to get confidence limits as follows:
Delaware=AnglerDiarySummaryData[AnglerDiarySummaryData$river==3,] #Getting data for river of interest
DelawareBoot = bootstrap(Delaware, sum(TotalTrout)/sum(TotalHours),B=5000)
This seems to work fine. However, I would like to do this repeatedly by year - there is a year variable in the data table. I could do the following for each year:
All2007=AnglerDiarySummaryData[AnglerDiarySummaryData$river==3 &AnglerDiarySummaryData$Year==2007,] #Data for river and year
All2007Boot = bootstrap(All2007, sum(TotalTrout)/sum(TotalHours),B=5000)
I could do this manually for each year, or write a function to loop through all the years, but I'm wondering if there is a more efficient way to this in SPlus. I imagine there is. The "group" argument for bootstrap does not seem to be what I want.
Also - I would like to put the results from each run into one matrix or data frame so that I can plot the means with error bars when all runs are done.
Any help would be greatly appreciated.
Thanks,
Jim Daley Coldwater Fisheries Unit Leader NYSDEC Bureau of Fisheries 625 Broadway, 5th Floor Albany, NY 12233-4753 jgdaley@gw.dec.state.ny.us |