[R] for loop using index values
Hi all
I have point data along a transect and I want to divide the transect into
small blocks of 10m length each. I have named the blocks as a list i.e
subset[[i]]. Now the issue is I want to process only those blocks that have
at least 100 data points and keep the original index values of those
subsets. How do I set the for loop. I have tried the following but it is
still processing everything
select-which(nrow(subset[[i]])=100
for (i in c(select)){
..
}
Thank you in advance,
David Gwenzi
Graduate Degree Program in Ecology
Natural Resources Ecology Lab
Colorado State University
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[R] Fwd: Intepreting lm() results with factor
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[R] R nls results different from those of Excel ??
Hi all I have a set of data whose scatter plot shows a very nice power relationship. My problem is when I fit a Power Trend Line in an Excel spreadsheet, I get the model y= 44.23x^2.06 with an R square value of 0.72. Now, if I input the same data into R and use model -nls(y~ a*x^b , trace=TRUE, data= my_data, start = c(a=40, b=2)) I get a solution with a = 246.29 and b = 1.51. I have tried several starting values and this what I always get. I was expecting to get a value of a close to 44 and that of b close to 2. Why are these values of a and b so different from those Excel gave me. Also the R square value for the nls model is as low as 0.41. What have I done wrong here? Please help. Thanks in advance David [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
