# Opposite of StatsBase.percentile
**URL:** https://discourse.julialang.org/t/opposite-of-statsbase-percentile/90592
**Category:** Statistics
**Created:** [November 21, 2022, 1:33pm UTC](https://discourse.julialang.org/t/opposite-of-statsbase-percentile/90592 "2022-11-21T13:33:33Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Piotr](https://discourse.julialang.org/u/Piotr)
#### Post date: [November 21, 2022, 1:33pm UTC](https://discourse.julialang.org/t/opposite-of-statsbase-percentile/90592/1 "2022-11-21T13:33:33Z")
This function returns a NUMBER for a given PERCENTILE.
I don’t know what the OP had in mind, but e.g. what I am looking for right now is exactly the thing that the name of this thread points to and which is the very opposite of the `percentile` function, i.e. given numbers in a collection, I would like to know their percentiles.
E.g. I have a long vector of numbers, and I would like to create another vector that contains percentiles of respective numbers in the original vector. How can I do that without writing a long program?
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### Author:  [@Paul\_Soderlind](https://discourse.julialang.org/u/Paul_Soderlind)
#### Post date: [November 21, 2022, 1:42pm UTC](https://discourse.julialang.org/t/opposite-of-statsbase-percentile/90592/2 "2022-11-21T13:42:26Z")
are you looking for [`StatsBase.ecdf`](https://juliastats.org/StatsBase.jl/stable/empirical/#StatsBase.ecdf)?
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### Author:  [@Dan](https://discourse.julialang.org/u/Dan)
#### Post date: [November 21, 2022, 1:58pm UTC](https://discourse.julialang.org/t/opposite-of-statsbase-percentile/90592/3 "2022-11-21T13:58:58Z")
`percentilerank` (or `quantilerank`). Also in StatsBase.
```julia
julia> v = [1,1,1,1,2,3,5,7]
julia> percentilerank.(Ref(v), [2,3])
2-element Vector{Float64}:
57.14285714285714
71.42857142857143
```
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### Author:  [@Piotr](https://discourse.julialang.org/u/Piotr)
#### Post date: [November 21, 2022, 2:04pm UTC](https://discourse.julialang.org/t/opposite-of-statsbase-percentile/90592/4 "2022-11-21T14:04:28Z")
The definition of this function includes a ‘vector of samples’. But what when I have just one sample, which is the whole distribution by the way?
I tried, so
`julia> ecdf([4;2;5;1;6;7]) ECDF{Vector{Int64}, Weights{Float64, Float64, Vector{Float64}}}([1, 2, 4, 5, 6, 7], Float64[])`
This does not return any percentiles to me. What do I do wrong?
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### Author:  [@Piotr](https://discourse.julialang.org/u/Piotr)
#### Post date: [November 21, 2022, 2:19pm UTC](https://discourse.julialang.org/t/opposite-of-statsbase-percentile/90592/5 "2022-11-21T14:19:58Z")
Many thanks, that’s roughly what I was looking for!
I had reproducing this plot in mind.
But it’s fairly easy to do it given `percentilerank`, thanks!
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### Author:  [@Paul\_Soderlind](https://discourse.julialang.org/u/Paul_Soderlind)
#### Post date: [November 21, 2022, 2:59pm UTC](https://discourse.julialang.org/t/opposite-of-statsbase-percentile/90592/6 "2022-11-21T14:59:43Z")
The `percentilerank` is just fine, but to answer your question:
`f = ecdf(X)` creates a function (similar to an interpolated percentilerank). You can use it later as `f(y)` or `f.(y)` where `y` are some values (eg same as `X`)