In jr-packages/jrAutomate: R Automate Exercises

library("jrAutomate")
library("shiny")
library("flexdashboard")

Exercise 1

• Create a R markdown document with a standard YAML header.
• In the main part of the document, have some R code that creates a simple scatter plot and saves the resulting plot as a pdf file,e.g. r x = rnorm(10) plot(x) pdf("fileA.pdf") plot(x) dev.off()
• Now in the YAML section, add a parameter called filename with the value file1.pdf
• In the main part of the document, access the parameter via params$filename
• Instead of fileA.pdf, pass the parameter from the YAML header
• Your R markdown document should display the scatter plot and save the plot in a file called file1.pdf

Exercise 2

• Copy your previous Rmd file, but delete the params section from the YAML header
• Pass the filename parameter via the render() function r rmarkdown::render("MyDocument.Rmd", params = list( filename = "file2.pdf" ) )
• Check that you have created file2.pdf

Exercise 3

Unfortunately, to run scheduler tasks it depends on

• Your operating system
• The requirement for admin privilages

This means it's hard to get an exercise that will suit everyone. To get the general idea across I've created a simple function called scheduler().

When we run the same script multiple times, there are two possibilities:

• We constantly overwrite the previous output (this is straightforward)
• We dynamically create file names so we have a record. This is what we'll do in the tasks below.

Exercise 3

Create a standard Rmd file (don't worry about params). In the body of the document include

x = rnorm(10)
plot(x)
pdf("fileA.pdf")
plot(x)
dev.off()

We want to change fileA.pdf to be unique. The easiest way is to use current time. In R we have

Sys.Date()
Sys.time()

In this exercise we'll use Sys.time(), but you may find Sys.Date() more suitable in general. We need to convert the time to a file name. First convert it to a character

fname = as.character(Sys.time())

Then add on a pdf file extension using the paste0() function

fname = paste0(as.character(Sys.time()), ".pdf")

Now change fileA.pdf to use fname. Run your script and ensure that it works.

Exercise 4

The scheduler() function is simple. It has three arguments:

• rmd_name: The name of Rmd script you want to generate
• repeats: How often should we run the script (from now)
• time_between: The time between script calls

library(jrAutomate)
## time between is in seconds
scheduler(script_name = "my_script.Rmd", repeats = 5, time_between = 5)

Using the scheduler() function, run your Rmd file 5 times with a 3 second interval.

Handy functions for file manipulation

Function name | Description --------------|------------ dir.create() | Creates a new directory dir.exists() | Checks a directory exists file.create() | Creates a new file file.exists() | Checks a file exists file.remove() | Removes a file file.info() | Size, creation date, etc.

jr-packages/jrAutomate documentation built on Dec. 14, 2019, 6:35 p.m.