 # How to obtain the critical value F0 of a F-distribution?

Hi,
I am not statistician and I need some advises to do a statistical test in Julia. I would like to obtain the critical value F0 of a F-distribution available for example in these tables
http://socr.ucla.edu/Applets.dir/F_Table.html

I read the Distributions.jl documentation, I found that it is possible to build a F-distribution, for example, with 5 and 2 degree of freedom

``````
julia> using Distributions
julia> d = FDist(5,2)
FDist{Float64}(ν1=5.0, ν2=2.0)
``````

The risk F0, for 5 and 2 degree of freedom in the F Table for α = 0.10 is F0 = 9.29263. But I did not managed to obtain this value because I didn’t find how to obtain the critical value in the documentation. Maybe there is another word to call this parameter… Is it possible ? Thank you for your help !

I think you are just looking for a quantile,

``````quantile(d, 1 - α)
``````
2 Likes

@Tamas_Papp, Exactly !!! I can reproduce all the values of the tables with the quantile. Thank you very much !

``````julia> d
FDist{Float64}(ν1=5.0, ν2=2.0)

julia> quantile(d, 1 - 0.1)
9.29262634632168
``````