Hi David, Thank you for your reply.
/Somehow I'm guessing that this will involve load an unnamed package. Yep: > ?create.fourier.descriptor No documentation for ‘create.fourier.descriptor’ in specified packages and libraries: you could try ‘??create.fourier.descriptor’/ So I indeed forgot to mention in my post that my script starts with *library('FourierDescriptors')* /> *count <- seq(1, 7, 0.06) > > for (i in 1:count){ I was also wondering what would happen when you passed a vector to the ":" operator. A warning at the very least. What was the point of this outer loop?/ I need the outer loop for changing the amplitude of my shapes at every iteration. I specified the amplitudes I want in count <- seq(1, 7, 0.06). This outer loop actually works (when I correct the "for (i in 1:count){" into "for (i in count){.") It generates in fact all the shapes I want. The problem is with the inner loop, it doesn't seem to save any png picture in my directory. The error is: *Error in switch(units, `in` = res, cm = res/2.54, mm = res/25.4, px = 1) * : non-numeric argument to binary operator* I report my all script here again: library('FourierDescriptors') count <- seq(1, 7, 1) # Controlled shapes for (i in count){ for (s in 1:length(count)){ png("~/Desktop/EMAS/FD_stimuli/s1_",s,".png") plot(create.fourier.descriptor(amplitude = c(0, i))); dev.off() } } Thank you for your help Best Ale -- View this message in context: http://r.789695.n4.nabble.com/Fourier-descriptors-created-in-a-loop-tp4632414p4632505.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.