R Package--ggplot2 (i)

<title>About Ggplot2 Package (i)</title> About Ggplot2 Package (i) Ggplot2 basic elements

• Data and Mapping (Mapping)
• Geometric objects (geometric)
• Ruler (scale)
• Statistical Transformations (Statistics)
• coordinate system (coordinate)
• Layers (layer)
• Faceted (facet)
• Theme (Theme)

Data and Mapping (Mapping)

The following is an example of diamonds data, because the data is very large, randomly select a subset to draw

> Library(ggplot2) 
> Data(diamonds) 
> Set. seed($) #设定生成随机数的种子 to make the results repeatable
> small<-diamonds[ Sample(Nrow (diamonds) , +),] #抽样
> head(small) 
Carat cutColorClarity DepthTablePrice x y z
49345  0.71Very Good H SI162.5     -  2096 5.68 5.75 3.57
50545  0.79Premium H SI161.8     -  2275 5.97 5.91 3.67
15434  1.03Ideal F SI162.4     $  6178 6.48 6.44 4.03
44792  0.50Ideal E VS262.2     Wu  1624 5.08 5.11 3.17
34614  0.27Ideal E VS161.6     About   470 4.14 4.17 2.56
27998  0.30Premium E VS261.7     -   658 4.32 4.34 2.67

Summary, please.

>Summary(Small)
     Carat               Cut      Color      Clarity        Depth      
 Min.: 0. 2200   Fair: 28D: 121   SI1    : 258   Min.:.  
1St Qu.: 0. 4000   Good: 88E: 186   VS2    : 2311St Qu.:. XX  
 Median : 0. 7100   Very Good: 227   F: 164   SI2    : 175   Median :.  
 Mean   : 0. 8187   Premium  : 257   G: 216   VS1    : 141   Mean   :.  
3Rd Qu.: 1. 0700   Ideal    :   H: 154   VVS2: 91 3Rd Qu.:. the  
 Max.: 2. 6600                   I: 106   VVS1: 67Max.:.  
                                  J: 53 ( Other): 37
     Table            Price               x               y        
 Min.:. Ten   Min. : 342. 0   Min.: 3. 850   Min.: 3. 840  
1St Qu.:. XX1St Qu.: 989. 51St Qu.: 4. 7401St Qu.: 4. 758  
 Median :. XX   Median: 2595. 0   Median : 5.   Median : 5. 775  


 Mean   :.   Mean: 4110. 5   Mean   : 5. 787   Mean   : 5. 791  
3Rd Qu.:. XX3Rd Qu.: 5495. 23Rd Qu.: 6. the3Rd Qu.: 6. 610  
 Max.:. XX   Max.: 18795. 0   Max.: 8. 830   Max.: 8. 870  

       Z        
 Min.: 2. the  
1St Qu.: 2. 920  
 Median : 3. 550  
 Mean   : 3. 572  
3Rd Qu.: 4. 070  
 Max.: 5. 580  

The number of carats (carat) is the x-axis variable, and the price is the y-axis variable

> p<-ggplot(data=small,mapping=aes(x=carat,y=price))#将数据映射到XY坐标轴上

Below, draw a scatter plot.

> p+geom_point()

If you want to map cut (cut) to shape properties:

> p<-ggplot(data=small,mapping=aes(x=carat,y=price,shape=cut))
> p+geom_point()

If you want to map the color attribute again (color):

> p<-ggplot(data=small,mapping=aes(x=carat,y=price,shape=cut,colour=color))
> p+geom_point()

Geometric objects (geometric)

In the above example, the various attribute mappings are performed by the Ggplot function, only one layer is added, and Geom_point () is used to tell Ggplot to draw a scatter plot, so all the attributes are mapped to the scatter point.

As for geom_histogram histogram, used for drawing geom_bar column chart, geom_boxplot for drawing box-type diagram and so on.

, you can also use the following code to draw

> p<-ggplot(small)
> p+geom_point(aes(x=carat,y=price,shape=cut,colour=color))

Histogram

>ggplot(small)+geom_histogram(aes(x=price))

You can also fill a color with another variable.

>ggplot(small)+geom_histogram(aes(x=price,fill=cut))

Again, they can be separated

>ggplot(small)+geom_histogram(aes(x=price, fill=cut)position="dodge")

You can also draw in relative proportions,

>ggplot(small)+geom_histogram(aes(x=price, fill=cut)position="fill")

Bar chart

ggplot(small)+geom_bar(aes(x=clarity))

The stat parameter allows Geom_bar to draw at a specified height,

ggplot()+geom_bar(aes(x=c(LETTERS[1:3]),y=1:3), stat="identity")

Density function diagram

ggplot(small)+geom_density(aes(x=price, colour=cut))

ggplot(small)+geom_density(aes(x=price,fill=clarity))

The colour parameter specifies the color, which fills the color below the curve

Box-type diagram

ggplot(small)+geom_boxplot(aes(x=cut, y=price,fill=color))

Here are a variety of geom_xxx functions

geom_abline    geom_area  

geom_bar       geom_bin2d

geom_blank     geom_boxplot  

geom_contour   geom_crossbar

geom_density   geom_density2d   

geom_dotplot   geom_errorbar

geom_errorbarh    

geom_hex       geom_histogram

geom_hline     geom_jitter   

geom_line      geom_linerange

geom_map       geom_path  

geom_point     geom_pointrange

geom_polygon   

geom_raster    geom_rect

geom_ribbon    geom_rug   

geom_segment   geom_smooth

geom_step      geom_text  

geom_tile      geom_violin

geom_vline

R Package--ggplot2 (i)