Here is a small example of how it could be done using for loops with the mtcars
dataset
for(g in unique(mtcars$gear)) {
f <- filter(mtcars, gear == g)
p <- ggplot(f, aes(disp, hp)) +
geom_point()
ggsave(paste0('plot_', g,'.jpg'), p)
}
In your case it would something like this
for(s in unique(WQ_byStation$StationName)){
f <- filter(WQ_byStation, StationName == s)
p <- ggplot(f, aes(x = Time_hr, y = DO_mgL)) +
geom_point() +
geom_line() +
ggtitle(s)
ggsave(paste0(s,'.jpg'), p)
}
Note you can save to a folder by specifying the path in ggsave
. E.g. my_folder/WQ_bySation...