i am running a Computational DCEMRI/DWI with the implementation of R's dcemriS4 library using the following line of code as a refence:

Question

TR <- 4.43 / 1000 # taken from CSV file dangle <- 25 # taken from CSV file (fflip <- list.files(pattern="ax[0-9]")) (fangles <- as.character(sub(".ax([0-9]+).", "\1", fflip))) flip <- array(NA, c(dim(mask), length(fangles))) for (fa in 1:length(fangles)) { flip[,,,fa] <- readNIfTI(fa) } `

The error is ... Error in strsplit(fname, "/") : non-character argument when i run the last line of code i need help please`