R语言 绘制特定点之间的线段 – segments() 函数

R语言中的 segment() 函数用于在特定的点之间绘制线段。

语法： segments(x0, y0, x1, y1)

参数：

x, y： 在所提供的点之间画一条线段的坐标。

返回： 给定点之间的线段

例1： 绘制一条线段

# Create empty example plot
plot(0, 0, col = "white", xlab = "", ylab = "")
  
# Draw one line
segments(x0 = - 1, y0 = - 0.5, x1 = 0.5, y1 = 0, col = "darkgreen") 

输出：

这里，x0和y0是线段的起点，x1和y1是线段的终点。

例2： 修改颜色、厚度和线型

# Create empty example plot
plot(0, 0, col = "white", xlab = "", ylab = "")
  
# Draw one line as in Example 1
segments(x0 = - 1, y0 = - 1, x1 = 0.5, y1 = 0.5,
           
         # Color of line
         col = "darkgreen",      
           
         # Thickness of line
         lwd = 5,                
           
         # Line type
         lty = "dotted")                     

输出：

例3： 绘制多条线段到R图。

# Create empty example plot
plot(0, 0, col = "white", xlab = "", ylab = "")       
  
# Create data frame with line-values
multiple_segments <- data.frame(x0 = c(0.1, 0.2, - 0.7, 0.4, - 0.8),   
                       y0 = c(0.8, 0.3, 0.5, - 0.4, 0.3),
                       x1 = c(0, 0.4, 0.5, - 0.5, - 0.7),
                       y1 = c(- 0.3, 0.4, - 0.5, - 0.7, 0.8))
                         
 # Draw multiple lines                       
 segments(x0 = multiple_segmentsx0,                   
         y0 = multiple_segmentsy0,
         x1 = multiple_segmentsx1,
         y1 = multiple_segmentsy1)

输出：