I am working with quantil binomial and runif functions with R to simulate values.
My goal is get relative frequency with this function. The frequency that I get are ok, but the the relative frequency are wrong, example:
set.seed(123)
table(qbinom(runif(1000,0,1),6,0.2))
0 1 2 3 4 5
277 367 245 88 22 1
#Relative Frequencies ???? wrong???
table(qbinom(runif(1000,0,1),6,0.2))/1000
0 1 2 3 4 5 6
0.271 0.402 0.239 0.071 0.014 0.002 0.001
My expected results are
0 1 2 3 4 5
0.277 0.367 0.245 0.088 0.022 0.001
I am ok? Thanks
runif is a random function, every time you run it you will get a different value. You are very unlikely to get the same value twice when you run table(qbinom(runif(1000,0,1),6,0.2)) twice. For example if I run this a few times I get
table(qbinom(runif(1000,0,1),6,0.2))
# 0 1 2 3 4 5
# 260 390 250 87 12 1
table(qbinom(runif(1000,0,1),6,0.2))
# 0 1 2 3 4 5
# 297 367 239 78 17 2
table(qbinom(runif(1000,0,1),6,0.2))
# 0 1 2 3 4 5
# 263 395 243 81 17 1
Dividing by 1000 will give relative frequencies for a particular instance.
If you want to get the same values, you could set your random seed before you call runif. For example
set.seed(616)
table(qbinom(runif(1000,0,1),6,0.2))
# 0 1 2 3 4 5
# 270 383 248 76 22 1
set.seed(616)
table(qbinom(runif(1000,0,1),6,0.2))
# 0 1 2 3 4 5
# 270 383 248 76 22 1
set.seed(616)
table(qbinom(runif(1000,0,1),6,0.2))/1000
# 0 1 2 3 4 5
# 0.270 0.383 0.248 0.076 0.022 0.001
Or just save your random values
set.seed(616)
rand_vals <- runif(1000,0,1)
table(qbinom(rand_vals,6,0.2))
# 0 1 2 3 4 5
# 270 383 248 76 22 1
table(qbinom(rand_vals,6,0.2))/1000
# 0 1 2 3 4 5
# 0.270 0.383 0.248 0.076 0.022 0.001