Ggplot2 drawing learning notes in R

Main records of this paper R In language ggplot2 Drawing package drawing image learning notes .
1.ggplot2 Introduce
ggplot2 The core idea of is to separate drawing and data , Data related plots are separated from data independent plots , Is to draw by layer .

ggplot2 The elements of the diagram can be summarized as follows ：
The biggest thing is plot（ Refers to the whole picture , Include background and title）, The second is axis（ Include stick,text,title and stick）、legend（ Include backgroud、text、title）、facet This is the second level , among facet It can be divided into external strip part （ Include backgroud and text） And internal panel part （ Include backgroud、boder And gridlines grid, The rough one is grid.major, Thin call grid.minor）.

2.ggplot2 Data set and plotting
（1） install ggplot2：Install.packages(“ggplot2”)
（2） call ggplot2：library(“ggplot2”)
（3） Load your own dataset ：data("iris")
（4） The plot ：

IrisPlot <- ggplot2(iris, aes(Sepal.Length, Petal.Length, colour=Species)) 
   + geom_point()
print(IrisPlot)

understand ：

• The data is iris;
• Graph attribute mapping ：Sepal.Length Corresponding x Axis ,Petal.Length Corresponding y Axis ;
• Geometry object ： Scatter plot ;
• The plus sign is used to add layer information ;
• Data and attribute information are contained in ggplot2 Inside .

Reference material ：
Book recommendation ：https://ggplot2-book.org/getting-started.html
an instruction manual ：https://www.tutorialspoint.com/ggplot2/ggplot2_quick_guide.htm