ggplot 画图1

ggplot2 : the grammar of graphics

哲学 ：点到图像的映射

title 标题 subtitle 副标题 panel 面板绘图区 background 背景板 geoms 几何对象 legend title 图例标题 legend labels 图例标签 legend symbols 图例符号 grid lines 网格线 axis text 坐标轴文本 axis.ticks 坐标轴刻度 axis.title 坐标轴标题

1 .1要安装的包

• tidyverse
• ggplot2
• dplyr 数据预处理
• tidyr 清理数据
• readr 读取数据

## 安装CRAN上的R包
install.packages(c("tidyverse", "colorspace", "corrr",  "cowplot", 
                   "ggdark", "ggforce", "ggrepel", "ggridges", "ggsci", 
                   "ggtext", "ggthemes", "grid", "gridExtra", "patchwork",
                   "rcartocolor", "scico", "showtext", "shiny", 
                   "plotly", "highcharter", "echarts4r"))
# 安装github上的R包
devtools::install_github("JohnCoene/charter")
chic <- readr::read_csv('C:\Users\JD\Downloads\chicago-nmmaps.csv')
library(tidyverse)
names(chic)
g <- ggplot(data = chic,aes(x = date,y = temp))
# aes() 为相应的映射，也就是将变量date映射到x轴，temp变量映射到y轴，当然也可以映射其他的变量到各种各样的美学属性，如颜色大小和形状
# ggplot2 允许将绘图对象存储为变量，之后可以通过添加图层来扩展这个ggplotobject，

图形中那么会是这样的呢？

• 因为，ggplot并不知道我们希望如何绘制该数据，我们应该改添加几何图形

1 .2添加集合对象

不同图形的集合对象通常都是以geom_开头的，示例

g + geom_point() # 用来创建一个散点图
# or
ggplot(data = chic,aes(x =  date,y = temp)) + geom_point()

g + geom_line()

我们也可以将多种几何图形组合起来，

g + geom_line() + geom_point()

1.3 更改几何图形的属性

在geom_* 中，我们可以设置一些属性，例如形状和颜色大小

g + geom_point(color = "firebrick",
              shape = 'diamond',
              size = 2)

g + geom_line() + geom_point(color = 'firebrick',
                            shape = 'diamond',
                            size = 2)

note:R 中可以将col识别为color

三原色：RGB 红绿蓝 ，也可以是RGBA，多出来的A表示透明度 表示方法rgb(255,0,0)

16禁止颜色 255对应的16进制就是FF，把三个数值一次并列起来，并且以# 开头

例如#FF0000 就是红色，#FFFF00就是表示黄色

g + geom_point(color ='#FFFF00',
              shape = 'diamond',
              size = 2)

g + geom_point(color = "#FF0000",
              shape = 'diamond',
              size = 2)

g + geom_point(col = rgb(255,0,0,maxColorValue = 255),
              shape = 'diamond',
              size = 5)

每个geom对象带有参数，不同的参数变换，会得到不同的图形

g + geom_point(col = 'firebrick',shape = 'diamond',size = 3) + geom_line(col = '#FFFFF1',size = 1)

1.4改变默认的ggplot2主题

默认的ggplot2是灰色白色的主题，我们通过调用theme_set(),将后面的plot将拥有相同的主题

g + geom_point(col = 'firebrick') + theme_set(theme_bw())

g + geom_point(col = 'firebrick') + theme_bw()

想转换为之前的主题

theme_set(theme_gray())

1.5 添加坐标轴

坐标轴的使用需要是labs() 函数

ggplot(chic,aes(x = date,y = temp)) + geom_point(color = 'firebrick') + labs(x = 'Year',y = 'Temperature(F)')

# 上面的等价于
ggplot(chic,aes(x = date,y = temp)) + geom_point(color = 'firebrick') + xlab('Year') + ylab('Temperature(F)')

也可以采用更复杂的方式，用expression()函数建立表达式，用来添加一些数学符号

ggplot(data = chic,aes(x = date,y = temp)) + geom_point(col = 'firebrick') + labs(x = 'year',y = expression(paste('Temperature(',degree~F,")"^"12312")))

1.6 增加坐标轴与坐标轴之间的空间

theme()函数是用来修改特定主题元素的基本命令例如文本标题符号北京，我们将会大量使用他

ggplot(chic,aes(x = date,y = temp)) + geom_point(color = 'firebrick') + labs(x = 'Year',y = 'Temperature') + theme(axis.title.x = element_text(vjust = 0,size =15),axis.title.y = element_text(vjust = 2,size = 15))

vjust ：表示的是垂直对齐，他的范围通常是在0-1之间，或者通过指定两个文本的边距来改变距离

ggplot(chic,aes(x = date,y = temp)) + geom_point(col = 'firebrick') + labs(x = 'year',y = 'Temperature') + theme(axis.title.x = element_text(margin = margin(t = 10),size = 15),axis.title.y = element_text(margin=margin(r = 10),size = 15))

margin(t,r,b,l) 中的top blow，right，left，这几个参数可以调整

ggplot(chic,aes(x = date,y = temp)) + geom_point(col = 'firebrick') + labs(x = 'year',y = 'Temperature') + theme(axis.title = element_text(margin = margin(t = 10),size = 15))

而且还可以改变坐标轴的样式，theme()函数，修改axis.title.x,axis.title.y元素

ggplot(chic,aes(x = date,y = temp)) + geom_point(col = 'firebrick') + labs(x = 'year',y = 'tempature') + theme(axis.title = element_text(size = 15,face = 'italic',color = 'red'))

axis.title = element_text()中的face参数是用来调节字体的，bold粗体，italic斜体，而且axis.title 是对x轴和y轴一起修改，axis.title.x,axis.title.y是对x轴和y轴的标题进行修改

ggplot(data = chic,aes(x = date,y = temp)) + geom_point(col = 'blue') + labs(x = 'year')+theme(axis.title = element_text(face = 'bold',color = 'green',size = 20))

ggplot(chic,aes(x = date,y = temp)) + geom_point(col = 'red') + labs(x = '123',y = '这个是y的标签') + theme(axis.title = element_text(color = 'blue',size = 25,face = 'bold.italic'))

g <- ggplot(chic,aes(x = date,y = temp)) + geom_point(col = 'red') + labs(x = '123',y = '这个是y的标签') + theme(axis.title = element_text(color = 'blue',size = 25,face = 'bold.italic'))
g + theme_set(theme_bw())

分别对坐标轴的x轴标签和y轴标签进行修改

ggplot(chic,aes(x = date,y = temp)) + geom_point(color = 'red') + labs(x = 'Year',y = 'tempature')  + theme(axis.title.x = element_text(color = 'green',face = 'bold',size = 10),axis.title.y = element_text(color = 'yellow',size = 20))

axis.tittle.x 会继承axis.title 的部分参数

1.7改变坐标轴文本的属性

使用axis.text 和axis.text.x axis.text.y来修改坐标轴刻度的外观，note 与刚才的标题不一样了，十分的不同

ggplot(chic,aes(x = date,y = temp))  + geom_point(col = 'firebrick') + labs(x = 'year',y = 'Temperature') + theme(axis.text = element_text(color = "dodgerblue",size = 12),axis.text.x = element_text(face = 'italic'))

1.8 旋转坐标轴文本的刻度

theme() 中的函数中具有参数angle允许你旋转文本，

ggplot(chic,aes(x = date,y = temp))  + geom_point(color = "firebrick") + labs(x = 'Year' ,y = 'Tempterature') + theme(axis.text.x = element_text(angle = 50,vjust = 1,hjust = 1,size = 12))

ggplot(chic,aes(x = date,y = temp))  + geom_point(color = "firebrick") + labs(x = 'Year' ,y = 'Tempterature') + theme(axis.text.x = element_text(angle = 120,vjust = 1,hjust = 1,size = 12))

不显示坐标轴

ggplot(data = chic,aes(x = date,y = temp)) + geom_point(color = 'firebrick') + labs(x = NULL,y = "")

不显示坐标轴的刻度

ggplot(chic,aes(x = date,y = temp)) + geom_point(color = 'firebrick') + labs(x = 'year',y = 'Temperature') + theme(axis.ticks.y = element_blank(),axis.text.y = element_blank())

限制坐标轴的取值范围

ggplot(chic,aes(x = date,y = temp)) + geom_point(col = 'dodgerblue')

ggplot(data = chic,aes(x = date,y = temp)) + geom_point(col = 'dodgerblue') + labs(x = 'year',y = 'temeperature') + ylim(c(0,110))

chic <- readr::read_csv('C:\Users\JD\Downloads\chicago-nmmaps.csv')
ggplot(data = chic,aes(x = date,y = temp)) + 
geom_point(col = 'dodgerblue') + 
labs(x = 'Year',y = 'Temperature') + 
ylim(c(0,60))
ggplot(chic, aes(x = date, y = temp)) +
  geom_point(color = "firebrick") +
  labs(x = "Year", y = "Temperature (°F)") +
  ylim(c(0, 50))

将绘制的图形强制从0点开始

ggplot(data = chic,aes(x = date,y = o3)) + geom_point(col = 'dodgerblue') + labs(x = 'Year',y = 'Temperature')  + coord_cartesian(xlim = c(0,NA),ylim = c(0,NA))
# date_trans works with objects of class Date only 这个是不可以的，因为其横坐标是日期型数据，所以不可能将其远点缩减为0，0
ggplot(data = chic,aes(x = temp,y = o3)) + geom_point(col = 'dodgerblue') + labs(x = 'Year',y = 'Temperature')  + coord_cartesian(xlim = c(0,NA),ylim = c(0,NA))

# or
ggplot(data = chic,aes(x = temp,y = o3)) + geom_point(col = 'dodgerblue') + labs(x = 'Year',y = 'Temperature')  + expand_limits(x = 0, y = 0)

将两个坐标轴保持尺度上的一致性

用到coord_equal()

ggplot(chic,aes(x = temp ,y = temp + rnorm(nrow(chic),sd = 20))) + geom_point(color = 'sienna') + labs(x = 'Temperature',y = 'Temperature + random.randn noise') + xlim(c(0,150)) + ylim(c(0,150)) + coord_fixed()

ggplot(chic,aes(x = temp ,y = temp + rnorm(nrow(chic),sd = 20))) + geom_point(color = 'sienna') + labs(x = 'Temperature',y = 'Temperature + random.randn noise') + xlim(c(0,200)) + ylim(c(0,200)) + coord_fixed()

ggplot(chic,aes(x = temp ,y = temp + rnorm(nrow(chic),sd = 20))) + geom_point(color = 'sienna') + labs(x = 'Temperature',y = 'Temperature + random.randn noise') + xlim(c(0,100)) + ylim(c(0,100)) + coord_fixed()

ggplot(chic,aes(x = temp ,y = temp + rnorm(nrow(chic),sd = 20))) + geom_point(color = 'sienna') + labs(x = 'Temperature',y = 'Temperature + random.randn noise') + xlim(c(0,100)) + ylim(c(0,100)) + coord_fixed(2)

添加标题

ggtitle() 函数可以为图形添加一个标题

ggplot(chic,aes(x = date,y = temp)) + geom_point(color = 'firebrick')+ labs(x = 'Year',y = 'Temperature') + ggtitle('Temperature in Chicage')

我觉得最好还是直接使用labs()函数直接一起带走就行

ggplot(chic,aes(x = date,y = temp)) + geom_point(col = 'firebrick') + labs(x = 'year',y = 'Temperature',
                                                                           title = 'Temperature in Chicago',
                                                                           suntitle = 'Seasonal pattern of daily temperatures from 1997 to 2001',
                                                                           caption = "Data:MMAPS",
                                                                           tag = 'Fig.1'
                                                                          ) 

caption: 说明

tag： 标签

更改标题的样式

对于这些文本的样式我们都可以使用theme() 函数，来进行修改，可使用的函数有，plot.subtitle plot.caption plot.tag legend.title, legend. text axix.title axis.text后面都是跟着element_text()

ggplot(chic,aes(x = date,y = temp)) + geom_point(col = 'firebrick') + labs(x = 'Year',y = 'Temperature',title = 'Temperature in Chicago') + theme(plot.title = element_text(face = 'bold',margin = margin(10,10,0,0),size = 14))

ggplot(chic,aes(x = date,y =temp)) + geom_point(col = 'firebrick') + labs(x = 'Year' ,y = 'Temperature',title = 'Thie is a title') + theme(axis.title = element_text(size = 20),plot.title = element_text(color = 'blue', face = 'bold',size = 20))

margin 中的参数为trouble，也即top right bottom left 也就是你眼前的顺时针

ggplot(chic, aes(x = date, y = temp)) +
  geom_point(color = "firebrick") +
  labs(x = "Year", y = "Temperature (°F)") +
  ggtitle("Temperatures in Chicago
from 1997 to 2001")

调整标题位置

ggplot(chic, aes(x = date, y = temp)) +
  geom_point(color = "firebrick") +
  labs(x = "Year", y = NULL,
       title = "Temperatures in Chicago",
       caption = "Data: NMMAPS") +
  theme(plot.title = element_text(hjust = 1, size = 16, face = "bold.italic"))

ggplot(chic, aes(x = date, y = temp)) +
  geom_point(color = "firebrick") +
  labs(x = "Year", y = NULL,
       title = "Temperatures in Chicago",
       caption = "Data: NMMAPS") +
  theme(plot.title = element_text(hjust = 0.5, size = 16, face = "bold.italic"))

vjust 来进行垂直控制