plot

plot包功能很强大，不同的type出图不同

plot(x2, type = "n", main = "不显示")
plot(x2, type = "p", main = "散点图")
plot(x2, type = "l", main = "折线图")
plot(x2, type = "b", main = "散点+间断折线")
plot(x2, type = "c", main = "间断折线")
plot(x2, type = "o", main = "散点+连续折线")
plot(x2, type = "h", main = "垂直于x轴")
plot(x2, type = "s", main = "楼梯形状")
plot(x2, type = "S", main = "反楼梯形状")

setseed类似固定这个随机数组

运算

• 算术运算符：基础，+-*/
• 关系运算符：==是否俩相等，!==是否不等于
• 逻辑运算符：based on T/F，和数值无关，所有大于1的数字被认为是逻辑值TRUE。
  &：它将第一向量的每个元素与第二向量的相应元素组合，并且如果两个元素都为TRUE，则给出输出TRUE

• 赋值运算符

  
  可以左边右边都有x