Create List of Files for Use in Function

[michaelgloven]

I have a Shiny app where I can read multiple files. Now, I'd like to collect these file objects in a list to use them in a function called evalm. The function works fine for one selected file but fails when I select multiple files and attempt to use them in the evalm function.

The error I get is Warning: Error in gzfile: invalid 'description' argument

files <- readRDS(file$datapath) # this reads in multiple files

results <- MLeval::evalm(list(files)) # works ok with one file but fails on more than one file selected above

I followed the evalm vignette using the exact syntax https://cran.r-project.org/web/packages/MLeval/vignettes/introduction.pdf

I believe I need to pass in a list, in this case they are caret models saved as .RDS files. Any suggestions on getting this to work is appreciated!

[AlexisW]

The function readRDS(file) expects the argument file to contain the path to a file. Here, you seem to be giving a vector with multiple paths (file$datapath seems to be the column of a data frame). So you need to loop on the elements of file$datapath and call readRDS() on each one. In R, the functions lapply() and purrr::map() are made for this purpose:

file$contents <- lapply(file$datapath, readRDS)

[michaelgloven]

Alexis, thanks, that works.