Seeking Inspiration from Random Learning

By Ken Koon Wong in R r random learning DT list.files

September 19, 2022


This was inspired by wanting to read a textbook Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. But, I didn’t want to read the textbook in sequence. Hence, I figured that if I read a paragraph a day in a random chapter, I might be able to benefit from random learning! This is also great for idea generation for some of our mysterious cases when we are still building differential diagnoses. But, how do we do that?

Thought process

  • 2 different workstations (personal and work)
    • Hence I will have 2 different directories. Need a system for this
  • Get all the pdf files of the textbook in my directory
  • Randomly select 1 pdf
  • Use DT to project the link to browser to read the pdf file

2 different workstations (personal and work)

# Get  
compname <-

# if the login is so_and_so, assign home as TRUE
if (compname["login"]=="so_and_so") {
  home <- TRUE } else { home <-FALSE }

# if home is TRUE then assign the following link
if (home) {
  pathurl <- "G:/My%20Drive/mandell/"
  path <- "G:/My Drive/mandell/"
} else {
  path <- "C:/Users/so_and_so/Documents/googledrive/mandell/"
  pathurl <- "C:/Users/so_and_so/Documents/googledrive/mandell/"
  • you can skip this if you are only using 1 computer, or computers with the same login
  • Obviously the so_and_so is a false login name, you will need to change that.
  • same with the path and pathurl as well, change it to whatever resource you want to point to
  • Note to self: I have to insert %20 in any white space of the directory in order for the URL to actually work

Get all the pdf files of the textbook in my directory

file <- list.files(paste0(path))

Randomly select 1 pdf

ran <- sample(file,1)


data <- tibble(link = paste0('<a  target=_blank href=file:///',pathurl, ran,'>',ran,'</a>' ))

datatable(data, escape=F)

Have to make sure that the html code <a target=_blank href=file:/// and sandwiches the pathurl and ran which is the actual file name

Then you can right-click on it and then click Open link in browser to open onto default PDF reader

Conclusion/Lessons Learnt:

  • Everyday random learning is fantastic! Sometimes it inspires me to think a bit differently when I approach a case
  • Learnt to add %20 to any white space if I want to use it as a URL link
  • Learnt about list.files
  • Learnt <a target=_blank href=file:///
  • Learnt that I could use DT to project the URL after putting into a tibble
  • Daily tips: I usually just highlight the end of paragraph where I left off and resume the next time if I stumble upon the same pdf
Posted on:
September 19, 2022
3 minute read, 440 words
R r random learning DT list.files
R r random learning DT list.files
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