Jenny Bryan Mon Oct 3 23:10:40 2016
Note: this is rendered by applying knitr::spin() to an R script. So the narrative is very minimal. load the data and ggplot2 (part of the tidyverse)
library(tidyverse)## Loading tidyverse: ggplot2
## Loading tidyverse: tibble
## Loading tidyverse: tidyr
## Loading tidyverse: readr
## Loading tidyverse: purrr
## Loading tidyverse: dplyr
## Conflicts with tidy packages ----------------------------------------------
## filter(): dplyr, stats
## lag(): dplyr, stats
library(gapminder)
gapminder## # A tibble: 1,704 × 6
## country continent year lifeExp pop gdpPercap
## <fctr> <fctr> <int> <dbl> <int> <dbl>
## 1 Afghanistan Asia 1952 28.801 8425333 779.4453
## 2 Afghanistan Asia 1957 30.332 9240934 820.8530
## 3 Afghanistan Asia 1962 31.997 10267083 853.1007
## 4 Afghanistan Asia 1967 34.020 11537966 836.1971
## 5 Afghanistan Asia 1972 36.088 13079460 739.9811
## 6 Afghanistan Asia 1977 38.438 14880372 786.1134
## 7 Afghanistan Asia 1982 39.854 12881816 978.0114
## 8 Afghanistan Asia 1987 40.822 13867957 852.3959
## 9 Afghanistan Asia 1992 41.674 16317921 649.3414
## 10 Afghanistan Asia 1997 41.763 22227415 635.3414
## # ... with 1,694 more rows
bar charts consider: no. of observations for each continent
table(gapminder$continent)##
## Africa Americas Asia Europe Oceania
## 624 300 396 360 24
this works because default stat for geom_bar() is "bin"
ggplot(gapminder, aes(x = continent)) + geom_bar()
let's reorder the continents based on frequency
p <- ggplot(gapminder, aes(x = reorder(continent, continent, length)))
p + geom_bar()
would you rather the bars run horizontally?
p + geom_bar() + coord_flip()
how about a better data:ink ratio?
p + geom_bar(width = 0.05) + coord_flip()
consider a scenario where you DON'T want the default "bin" stat, i.e. the bar length or height already exists as a variable
(continent_freq <- gapminder %>% count(continent))## # A tibble: 5 × 2
## continent n
## <fctr> <int>
## 1 Africa 624
## 2 Americas 300
## 3 Asia 396
## 4 Europe 360
## 5 Oceania 24
this simple call no longer works, because we have pre-tabulated
ggplot(continent_freq, aes(x = continent)) + geom_bar()
THIS works when bar length or height already exists
ggplot(continent_freq, aes(x = continent, y = n)) + geom_bar(stat = "identity")
sessionInfo()## R version 3.3.1 (2016-06-21)
## Platform: x86_64-apple-darwin13.4.0 (64-bit)
## Running under: OS X 10.11.6 (El Capitan)
##
## locale:
## [1] en_CA.UTF-8/en_CA.UTF-8/en_CA.UTF-8/C/en_CA.UTF-8/en_CA.UTF-8
##
## attached base packages:
## [1] stats graphics grDevices utils datasets methods base
##
## other attached packages:
## [1] gapminder_0.2.0 dplyr_0.5.0 purrr_0.2.2 readr_1.0.0.9000
## [5] tidyr_0.6.0.9000 tibble_1.2 ggplot2_2.1.0 tidyverse_1.0.0
## [9] knitr_1.14.2
##
## loaded via a namespace (and not attached):
## [1] Rcpp_0.12.7 magrittr_1.5 munsell_0.4.3
## [4] colorspace_1.2-6 R6_2.1.3 stringr_1.1.0
## [7] plyr_1.8.4 tools_3.3.1 grid_3.3.1
## [10] gtable_0.2.0 DBI_0.4-1 htmltools_0.3.5
## [13] lazyeval_0.2.0 yaml_2.1.13 assertthat_0.1
## [16] digest_0.6.10 formatR_1.4 evaluate_0.9
## [19] rmarkdown_1.0.9014 labeling_0.3 stringi_1.1.1
## [22] scales_0.4.0