R语言与医学统计图形-【14】ggplot2几何对象之直方密度图
ggplot2绘图系统——几何对象之直方图、密度图
1.直方图
参数。
geom_histogram(mapping = , data = , stat = 'bin', #统计变换,概率密度为density position = 'stack', binwidth = , #条柱宽度 bins = , #条柱数目,默认30 na.rm = FALSE, show.legend = NA, inherit.aes = TRUE )
示例。
ggplot(diamonds,aes(carat))+ geom_histogram(fill='darkorchid4') ggplot(diamonds,aes(carat))+ geom_histogram(fill='darkorchid4',bins=45)+ xlim(0,3)
# bins和binwidth ggplot(diamonds,aes(carat))+ geom_histogram(fill='darkorchid4',bins = 300) ggplot(diamonds,aes(carat))+ geom_histogram(fill='darkorchid4',binwidth = 0.01) #binwidth参数是一个相对宽度
#颜色映射 ggplot(diamonds,aes(price,fill=cut))+ geom_histogram(binwidth = 500)
2.概率密度曲线
三种方法:
#stat=density ggplot(diamonds,aes(price))+ geom_histogram(color='darkorchid4',stat='density') #aes映射,..density..表示将y轴表示为density ggplot(diamonds,aes(price, ..density..))+ geom_histogram(fill='darkorchid4',color='black') #geom_density ggplot(diamonds,aes(depth,fill=cut,color=cut))+ geom_density(alpha=0.1)+xlim(55,70)