#include <algorithm>
#include "TMath.h"
void KStest()
{
	const int n = 1000; //number of entries in arrays
	const int N= 2000; //number of kolmogorov probabilities (how many times i perform the test)

	Double_t a,b,Ktest1;
	Double_t arr1[n], arr2[n];

	//histogram of kolmogorow probabilities
	TH1F *unbinnedyes = new TH1F ("unbinnedyes","KS unbinned same", 100,0,1);
	unbinnedyes->SetFillColor(kGreen);
	
	for (int j=0; j<N;j++)
	{	
		for (int i=0; i<n; i++)	
		{
		//generate 2 samples of same distribution, fill values into array
			a=gRandom->Uniform();
			b=gRandom->Uniform();
			arr1[i]=a;
			arr2[i]=b;
		}
	//sort the array
		std::sort(arr1,arr1+n);
		std::sort(arr2,arr2+n);

	//do kolmogorov test for unbinned data, fill the probability values into histogram
		Ktest1 = TMath::KolmogorovTest (n, arr1,n,arr2,"");
		unbinnedyes->Fill(Ktest1);
	}
	//plot the distribution of KS probability - supposed to be flat!
	unbinnedyes->Draw();
}