Suppose I want to create a sample of N elements chosen from [1,2,3] such that 1, 2 and 3 will be represented with weights 0.4,0.4 and 0.2 respectively. How would I do this.
I know how to do it in R without using loops:
mySample <- sample(c(1,2,3),size = 100,replace=T,prob = c(.4,.4,.2)) You can generate a random number in [0,1) then if it is in [0,.4) pick "1", else if it is in [.4,.8) pick "2" and else pick "3". the code is:
from random import random; N = 10; elements = [1,2,3]; weights = [.4, .4 , .2]; samples = range(N); r = 0; temp = 0; for i in range(10): r = random(); temp = 0; for j in range(len(elements)): temp += weights[j]; if(temp>r): samples[i] = elements[j]; break; 