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+class activity 3
+Minruo Wang
+10/2/2019
+ +
+
+Learn
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+
+Useful links
+ +
+
+Mapping aesthetic to data to = layer
+# install.packages("ggplot2")
+library(ggplot2)
+
+ggplot(diamonds, aes(x = price, y = carat)) +
+ geom_point()
+
+Two layers
+ggplot(mpg, aes(reorder(class, hwy), hwy)) +
+ geom_jitter() + # adds a small amount of random variation to the location of each point
+ geom_boxplot()
#Plot count
+ggplot(diamonds, aes(depth)) +
+ geom_histogram(aes(y = ..count..), binwidth=0.2) +
+ facet_wrap(~ cut) + xlim(50, 70)## Warning: Removed 26 rows containing non-finite values (stat_bin).## Warning: Removed 10 rows containing missing values (geom_bar).
#Plot density
+ggplot(diamonds, aes(depth)) +
+ geom_histogram(aes(y = ..density..), binwidth=0.2) +
+ facet_wrap(~ cut) + xlim(50, 70)## Warning: Removed 26 rows containing non-finite values (stat_bin).
+
+## Warning: Removed 10 rows containing missing values (geom_bar).
ggplot(mpg, aes(displ, hwy, color = class)) +
+ geom_point()
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+
+
+Exercise
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+1. Can you create a line graph using the “economics_long” data set that shows change over time in “value01” for different categories of “variable”?
+# show in one graph
+ggplot(economics_long, aes(date, value01, color = variable)) +
+ geom_line()
# show in facet
+ggplot(economics_long, aes(x = date, y = value01, color = variable)) +
+ geom_line() +
+ facet_wrap(~ variable)
+
+2. If you would like to recreate the Minard graphic of Napoleon’s Troops the code is below and the data is in this repo.
+# load and merge the data
+cities <- read.table("cities.txt", header = TRUE, sep = "")
+troops <- read.table("troops.txt", header = TRUE, sep = "")
+temps <- read.table("temps.txt", header = TRUE, sep = "")
+Napo <- merge(cities, troops, by = c("long", "lat"), all = TRUE)
+Napoleon <- merge(Napo, temps, by = "long", all = TRUE)# Napoleon's troops route
+route <- ggplot(Napoleon, aes(long, lat)) +
+ geom_path(aes(size = survivors, colour = direction,
+ group = interaction(group, direction)),
+ data = troops) +
+ geom_text(aes(label = city), hjust = 0, vjust = 1, size = 4) +
+ scale_x_continuous("", limits = c(24, 39)) +
+ scale_y_continuous("") +
+ scale_colour_manual(values = c("grey50","red")) +
+ scale_size(range = c(1, 10))
+# show the graph
+route## Warning: Removed 43 rows containing missing values (geom_text).
# save the graph using ggsave
+ggsave(route, file = "Napoleon-route.png")## Saving 7 x 5 in image## Warning: Removed 43 rows containing missing values (geom_text).