CODEWITHSUNDEEP
rfunction
user20442889
user20442889

Reputation:

R clarification of the meaning of the formula

I have code:

x1=rnorm(100,-10,1)
sum(x1>quantile(x1,0.05))/length(x1)

What exactly the second line of code does?

Upvotes: 0

Views: 24

Answers (1)

Jon Spring
Jon Spring

Reputation: 66415

x1 is 100 normally distributed #s from a population with mean of -10.

quantile(x1,0.05) identifies the 5th percentile of that vector.

x1>quantile(x1,0.05) tests each element in x1 to see if it's more than that 5th percentile, outputting TRUE (aka 1) if so, so its sum is a count of elements larger than the 5th percentile.

Finally, it's divided by the number of elements in x1: 100. So we're checking what percentage of the values are more than the 5th percentile. I'd expect 95%.

Upvotes: 1

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