从另一个向量中查找向量的索引

Question

I have three vectors a, r and b . I want to check the first element of r is between zero and first element of vector a , if yes then put zero from vector b , if not , its belong to what interval and then extract the value form vector b , ...How can I do this in R?at the end I should have a vector with sample 20 and the values belong to vector b .

      a =c(0.1531532, 0.2432432, 0.3243243, 0.3648649, 0.3873874, 0.4054054, 
       0.4594595, 0.5720721, 0.7522523, 1.0000000)
      set.seed(2)
      r = runif(20, 0, 1)
      b = 0:9
      result = c( 1, 8, 8, 1, 9, 9, 0, 9, 7, 7, 7, 1, 9, 1, 5, 9, 9, 1, 6, 0)

Answer 1

R> a = c(0, a)
R> cut(r, a, labels = b)
 [1] 1 8 8 1 9 9 0 9 7 7 7 1 9 1 5 9 9 1 6 0
Levels: 0 1 2 3 4 5 6 7 8 9