R is a wonderfully confusing language. Fortunately, people like Hadley Wickham are here to help. Therefore, most of these commands will be in the context of packages like dplyr and ggplot.

If you are in need of some more general plotting advice, take a look at the Compendium of Clean Graphs in R.

Working with Strings

Sometimes you want to create a cartesian product of multiple lists of strings. Well friend, Sven Hohenstein has got you covered. In short, add the following function to your code:

combine2 <- function(..., prefix="", sep="") {
  paste0(prefix, levels(interaction(..., sep=sep)))
}

Examples:

a <- c('a', 'b')
b <- c('1', '2', '3')
c <- c('??', '!!)

combine2(a, b)
#[1] "a1" "b1" "a2" "b2" "a3" "b3"

combine2(a, b, c)
#[1] "a1!!" "b1!!" "a2!!" "b2!!" "a3!!" "b3!!" "a1??" "b1??" "a2??" "b2??" "a3??" "b3??"

Dataframes

Use df %>% group_by(X) %>% tally for a nice quick summary of a dataframe.

Get number of rows in the dataframe: nrow(df).

Working With Files

Write delimited file without quotes, row, and column labels:

df %>% write.table('gtlds.txt', row.names=FALSE, col.names=FALSE, quote=FALSE)

Read a csv using the readr package: df <- read_csv('test.csv').

RStudio

Shortcut for the dplyr operator (%>%): Cmd+shft+m.

ggplot

Force commas in axis labels:

library(scales)

ggplot(df, aes(x=foo)) +
  stat_ecdf() +
  scale_x_continuous(labels=comma)

Quantiles

quantile(df$foo, probs=seq(0,1,0.25))