Tidyverse

Пакет языка R

• Hadley Wickham and Garrett Grolemund - R for Data Science
  Import, Tidy, Transform, Visualize, and Model Data
  • https://github.com/hadley/r4ds

• install.packages("tidyverse")
  • library(tidyverse)

Transform

dplyr Basics

• Pick observations by their values
  • (filter()). - filter(flights, month == 1, day == 1)
• Reorder the rows
  • (arrange()) - arrange(flights, desc(arr_delay))
• Pickvariables by their names
  • (select()). select(flights, year, month, day) select(flights, -(year:day))
• Create new variables with functions of existing variables
  • (mutate()). - mutate() always adds new columns at the end of your dataset
• Collapse many values down to a single summary
  • (summarize()).

Select

select(flights, -(year:day))

Summarize

sum(!is.na(x))

not_cancelled %>%
group_by(dest) %>%
summarize(carriers = n_distinct(carrier)) %>%
arrange(desc(carriers))

not_cancelled %>%
count(dest)

Visualize

ggplot(data = mpg) +
geom_point(mapping = aes(x = displ, y = hwy))

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ggplot(data = mpg) +
geom_point(mapping = aes(x = displ, y = hwy, color = class))

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ggplot(data = mpg) +
geom_point(mapping = aes(x = displ, y = hwy, size = class))

Facets

ggplot(data = mpg) +
geom_point(mapping = aes(x = displ, y = hwy)) +
facet_wrap(~ class, nrow = 2)

Statistical Transformations

ggplot(data = diamonds) +
geom_bar(mapping = aes(x = cut))

ggplot(data = diamonds) +
stat_count(mapping = aes(x = cut))

Coordinate Systems

• coord_flip() switches the x- and y-axes.

ggplot(data = mpg, mapping = aes(x = class, y = hwy)) +
geom_boxplot() +
coord_flip()

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