introduction to ggplot2 from Wickham and Grolemund' chapter 1
#scatterplot
#build coordinate system at global level, and geom_ function at local level
library(ggplot2)
ggplot(data = mpg)+
geom_point(mapping = aes(x=displ, y=hwy))
g <- ggplot(data = mpg)
g+geom_point(mapping = aes(x=displ, y=hwy, color=class))
g+geom_point(aes(x=displ, y=hwy, size=class))
## Warning: Using size for a discrete variable is not advised.
g+geom_point(aes(x=displ, y=hwy, alpha=class))
## Warning: Using alpha for a discrete variable is not advised.
g+geom_point(aes(x=displ, y=hwy, shape=class)) #the 7th category is not plotted
## Warning: The shape palette can deal with a maximum of 6 discrete values because more than 6 becomes difficult to
## discriminate; you have 7. Consider specifying shapes manually if you must have them.
## Warning: Removed 62 rows containing missing values (geom_point).
g+geom_point(aes(x=displ, y=hwy), color="blue")
#facets
g+geom_point(aes(x=displ, y=hwy))+
facet_wrap(~class, nrow=2)
g+geom_point(aes(x=displ, y=hwy))+
facet_wrap(~class) #by default nrow=3
g+geom_point(aes(x=displ, y=hwy))+
facet_grid(~class)
g+geom_point(aes(x=displ, y=hwy))+
facet_grid(drv ~ cyl)
g+geom_point(aes(x=displ, y=hwy))+
facet_grid(. ~ cyl)
g+geom_point(aes(x=displ, y=hwy))+
facet_grid(drv ~ .)
g+geom_point(aes(x=displ, y=hwy))+
facet_wrap(drv ~ .)
g+geom_point(aes(x=displ, y=hwy))+
facet_grid(. ~ drv)
#lines (use of group, color, and linetype)
#by default, geom_smooth use method="loess"
g+geom_point(aes(x=displ, y=hwy))
g+geom_smooth(aes(x=displ, y=hwy))
## `geom_smooth()` using method = 'loess' and formula 'y ~ x'
g+geom_smooth(aes(x=displ, y=hwy, linetype=drv)) #with legend
## `geom_smooth()` using method = 'loess' and formula 'y ~ x'
g+geom_point(aes(x=displ, y=hwy))+
geom_smooth(aes(x=displ, y=hwy))
## `geom_smooth()` using method = 'loess' and formula 'y ~ x'
g+geom_point(aes(x=displ, y=hwy))+
geom_smooth(aes(x=displ, y=hwy, group=drv),
show.legend = T) #do not add legend
## `geom_smooth()` using method = 'loess' and formula 'y ~ x'
#local level
#g+geom_point(aes(x=displ, y=hwy))+
# geom_smooth(aes(group=drv),
# show.legend = T)
g+geom_point(aes(x=displ, y=hwy))+
geom_smooth(aes(x=displ, y=hwy, color=drv),
show.legend = T)
## `geom_smooth()` using method = 'loess' and formula 'y ~ x'
g <- ggplot(data = mpg, mapping = aes(x=displ, y=hwy))
g+geom_point()+geom_smooth()
## `geom_smooth()` using method = 'loess' and formula 'y ~ x'
g+geom_point(aes(color=class))+geom_smooth()
## `geom_smooth()` using method = 'loess' and formula 'y ~ x'
#g+geom_point(aes(color=class))+geom_smooth(
# data = filter(mpg, class=="subcompact"),
# se=FALSE,
# method = "lm"
#)
ggplot(data = diamonds)+
stat_count(mapping = aes(x=cut))
ggplot(data = diamonds)+
geom_bar(mapping = aes(x=cut))
#ggplot(data = diamonds)+
# geom_histogram(mapping = aes(x=cut))#do not work; x needs to be a continuous variable
ggplot(data = diamonds)+
geom_histogram(mapping = aes(x=cut), stat = "count")
## Warning: Ignoring unknown parameters: binwidth, bins, pad
ggplot(data = diamonds)+
stat_summary(mapping = aes(x=cut, y=depth),
fun.ymax = max,
fun.ymin = min,
fun.y = median)
## Warning: `fun.y` is deprecated. Use `fun` instead.
## Warning: `fun.ymin` is deprecated. Use `fun.min` instead.
## Warning: `fun.ymax` is deprecated. Use `fun.max` instead.
?stat_summary
#position adjustments
ggplot(data = diamonds)+
geom_bar(mapping = aes(x=cut, color=cut))
ggplot(data = diamonds)+
geom_bar(mapping = aes(x=cut, fill=cut))
ggplot(data = diamonds)+
geom_bar(mapping = aes(x=cut, fill=clarity))
#position
ggplot(data = diamonds,
mapping = aes(x=cut, fill=clarity))+
geom_bar(alpha=1/5, position = "identity")
ggplot(data = diamonds,
mapping = aes(x=cut, color=clarity))+
geom_bar(fill=NA, position = "identity")
#position=fill - stacking
ggplot(data = diamonds)+
geom_bar(mapping = aes(x=cut, fill=clarity),
position = "fill")
#dodge-besides each other
ggplot(data = diamonds)+
geom_bar(mapping = aes(x=cut, fill=clarity),
position = "dodge")
#add some random noise
table(mpg$displ)
##
## 1.6 1.8 1.9 2 2.2 2.4 2.5 2.7 2.8 3 3.1 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 4.2 4.4 4.6 4.7 5 5.2 5.3 5.4 5.6 5.7 5.9
## 5 14 3 21 6 13 20 8 10 8 6 9 4 5 2 3 8 3 15 4 1 11 17 2 5 6 8 1 8 2
## 6 6.1 6.2 6.5 7
## 1 1 2 1 1
ggplot(data = mpg)+
geom_point(mapping = aes(x=displ, y=hwy),
position = "jitter")
#coordinate system
ggplot(data = mpg, mapping = aes(x=class, y=hwy))+
geom_boxplot()
ggplot(data = mpg, mapping = aes(x=class, y=hwy))+
geom_boxplot()+
coord_flip()
nz<- map_data("nz")
ggplot(nz, aes(long, lat, group=group))+
geom_polygon(fill="white", color="black")
#coord_quickmap() sets the aspect ratio correctly
ggplot(nz, aes(long, lat, group=group))+
geom_polygon(fill="white", color="black")+
coord_quickmap()
bar <- ggplot(data = diamonds)+
geom_bar(mapping = aes(x=cut, fill=cut),
show.legend = F, #don't add legend
width = 1)+
theme(aspect.ratio = 1)+
labs(x=NULL, y=NULL) #don't add anything on x,y-axis
bar+coord_flip()
