[R] create separate plots by factors

Hello, I am attempting to create several plots based on "site" (~300 total) and am having trouble with the code. I simply want to create a plot using the code, plot(year, peak), for the following dataset. I would like for each site to be plotted on a separate page and the plots saved in a

[R] T-test by groups

I would like to run a t-test within a "by" group function. My dataset, "error", is organized as the following (I have 133 Sites): Site week Dataset Region lat_map long_map mean_tsim diff20 diff40 diff80 ALFI 15 USACE UC 48.15625 -117.0938 8.87 1.34 1.90 2.98 ALFI 16

[R] for loop or "by" group in EF function

Hello, I would like to apply the EF function (a goodness of fit test between predicted (ts2) and observed (Tw) values in the qualV package) to each of the Sites in my data frame. However, when I try the following script, R gives an error message that lists unused arguments, which include th

[R] cbind results to original data frame

I have the following script, which gives me a prediction for each of my observations (> 49k), and subsets my data frame by site (n = 183): ts <- (by(dem16,dem16['Site'],function(dat) try(predict(nls(Tw ~ mu + ((alpha - mu)/ (1 + exp(gamma*(B - Mean_air

[R] for loop in nls function

Hello, I am trying to apply a least squares non-linear regression to my dataset, dem16. I can apply it to a subset based on a single site fine, but I want to apply it to each (of 197) sites. I am stumbling over a "for" loop. Site and Mean_Air are variables in my dataset and I would like to