Jenny Bryan Mon Oct 3 23:49:33 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
distribution of a quant var: histogram
ggplot(gapminder, aes(x = lifeExp)) +
geom_histogram()## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
experiment with bin width; think in terms of the units of the x variable
ggplot(gapminder, aes(x = lifeExp)) +
geom_histogram(binwidth = 1)
show the different continents, but it's weird to stack up the histograms, which is what default of position = "stack" delivers
ggplot(gapminder, aes(x = lifeExp, fill = continent)) +
geom_histogram()## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
position = "identity" is good to know about it's still weird to layer them on top of each other like this
ggplot(gapminder, aes(x = lifeExp, fill = continent)) +
geom_histogram(position = "identity")## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
geom_freqpoly() is better in this case
ggplot(gapminder, aes(x = lifeExp, color = continent)) +
geom_freqpoly()## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
smooth histogram = densityplot
ggplot(gapminder, aes(x = lifeExp)) + geom_density()
you should look at different levels of smoothing
ggplot(gapminder, aes(x = lifeExp)) + geom_density(adjust = 1)
ggplot(gapminder, aes(x = lifeExp)) + geom_density(adjust = 0.2)
densityplots work better in terms of one continent not obscuring another
ggplot(gapminder, aes(x = lifeExp, color = continent)) + geom_density()
alpha transparency works here too
ggplot(gapminder, aes(x = lifeExp, fill = continent)) +
geom_density(alpha = 0.2)
with only two countries, maybe we should ignore Oceania?
ggplot(subset(gapminder, continent != "Oceania"),
aes(x = lifeExp, fill = continent)) + geom_density(alpha = 0.2)
facets work here too
ggplot(gapminder, aes(x = lifeExp)) + geom_density() + facet_wrap(~ continent)
ggplot(subset(gapminder, continent != "Oceania"),
aes(x = lifeExp, fill = continent)) + geom_histogram() +
facet_grid(continent ~ .)## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
boxplot for one quantitative variable against a discrete variable first attempt does not work since year is not formally a factor
ggplot(gapminder, aes(x = year, y = lifeExp)) + geom_boxplot()## Warning: Continuous x aesthetic -- did you forget aes(group=...)?
by explicitly specifying year as the grouping variable, we get what we want
ggplot(gapminder, aes(x = year, y = lifeExp)) + geom_boxplot(aes(group = year))
try geom_violin() instead and just generally goofing off now
ggplot(gapminder, aes(x = year, y = lifeExp)) +
geom_violin(aes(group = year)) +
geom_jitter(alpha = 1/4) +
geom_smooth(se = FALSE)