绘制qq图

在ggplot2中绘制qq图需要两步，geom_qq()将绘制样本分位点，geom_qq_line()将绘制标准正态线

函数介绍

geom_qq()

geom_qq(mapping = NULL,data = NULL,geom = "point",position = "identity",...,distribution = stats::qnorm,dparams = list(),na.rm = FALSE,show.legend = NA,inherit.aes = TRUE
)

geom_qq_line(mapping = NULL,data = NULL,geom = "path",position = "identity",...,distribution = stats::qnorm,dparams = list(),line.p = c(0.25, 0.75),fullrange = FALSE,na.rm = FALSE,show.legend = NA,inherit.aes = TRUE
)

参数介绍

**aes()**中的映射参数必须包含sample，可选参数有group,x,y distribution
Distribution function to use, if x not specified
dparams Additional parameters passed on to distribution function.
line.p Vector of quantiles to use when fitting the Q-Q line, defaults defaults to c(.25, .75).
fullrange Should the q-q line span the full range of the plot, or just the data

注意事项

**aes()**中的映射参数必须包含sample

例子

Using to explore the distribution of a variable

ggplot(mtcars, aes(sample = mpg)) +stat_qq() +stat_qq_line()
ggplot(mtcars, aes(sample = mpg, colour = factor(cyl))) +stat_qq() +stat_qq_line()

绘制boxplot

函数介绍

geom_boxplot(mapping = NULL,data = NULL,stat = "boxplot",position = "dodge2",...,outlier.colour = NULL,outlier.color = NULL,outlier.fill = NULL,outlier.shape = 19,outlier.size = 1.5,outlier.stroke = 0.5,outlier.alpha = NULL,notch = FALSE,notchwidth = 0.5,varwidth = FALSE,na.rm = FALSE,orientation = NA,show.legend = NA,inherit.aes = TRUE
)

参数介绍

aes()可接收的参数有：

x or y， 利用x将会是横向箱线图，y的是纵向

lower or xlower

upper or xupper

middle or xmiddle

ymin or xmin

ymax or xmax

alpha

colour

fill

group

linetype

shape

size

weight

notch If FALSE (default) make a standard box plot. If TRUE, make a notched box plot. Notches are used to compare groups; if the notches
of two boxes do not overlap, this suggests that the medians are
significantly different.

notchwidth For a notched box plot, width of the notch relative to the body (defaults to notchwidth = 0.5).

varwidth If FALSE (default) make a standard box plot. If TRUE, boxes are drawn with widths proportional to the square-roots of the
number of observations in the groups (possibly weighted, using the
weight aesthetic).

例子

p <- ggplot(mpg, aes(x=class, y=hwy))
p + geom_boxplot()

ggplot(mpg, aes(x=hwy, y=class)) + geom_boxplot()

p <- ggplot(mpg, aes(x=class, y=hwy))
p + geom_boxplot(notch = TRUE,varwidth = TRUE,fill = "white", colour = "#3366FF")

ggplot(diamonds, aes(carat, price)) +geom_boxplot(aes(group = cut_width(carat, 0.25)))

p <- ggplot(mpg, aes(x=class, y=hwy))
p + geom_boxplot(outlier.shape = NA) + geom_jitter(width = 0.2)

利用分位点绘制箱线图

y <- rnorm(100)
df <- data.frame(x = 1,y0 = min(y),y25 = quantile(y, 0.25),y50 = median(y),y75 = quantile(y, 0.75),y100 = max(y)
)
ggplot(df, aes(x)) +geom_boxplot(aes(ymin = y0, lower = y25, middle = y50, upper = y75, ymax = y100),stat = "identity")

将qq图和箱线图进行融合

函数介绍

该函数是来自于qqboxplot包，因此使用前需要安装

geom_qqboxplot(mapping = NULL,data = NULL,stat = "qqboxplot",position = "dodge2",...,outlier.colour = NULL,outlier.color = NULL,outlier.fill = NULL,outlier.shape = 19,outlier.size = 1.5,outlier.stroke = 0.5,outlier.alpha = NULL,notch = FALSE,notchwidth = 0.5,varwidth = FALSE,na.rm = FALSE,show.legend = NA,inherit.aes = TRUE
)

参数介绍

大部分参数和geom_qq()和geom_boxplot()中的参数含义相同
reference_dist 表示参数比较的标准分布名称，如果有参数需要有dparams
compdata 用于比较的标准样本数据，是个向量

注意事项

aes()函数中的y不可缺

例子

library(dplyr)
library(ggplot2)
library(qqboxplot)simulated_data=tibble(y=c(rnorm(1000, mean=2), rt(1000, 16), rt(500, 4), rt(1000, 8), rt(1000, 32)),group=c(rep("normal, mean=2", 1000), rep("t distribution, df=16", 1000), rep("t distribution, df=4", 500), rep("t distribution, df=8", 1000), rep("t distribution, df=32", 1000)))
p <- ggplot2::ggplot(simulated_data, ggplot2::aes(factor(group,levels=c("normal, mean=2", "t distribution, df=32", "t distribution, df=16","t distribution, df=8", "t distribution, df=4")), y=y))
p + geom_qqboxplot()
p + geom_qqboxplot(reference_dist = "norm")p + geom_qqboxplot(compdata = comparison_dataset)