;This routine computes the kolmogorov-Smirnov test for the null hypothesis
; that two set of data have the same probability distribution.
; A number close to 0 means the two datasets have different probability distribution
;iplot = 1 means plot the cumulative probability distributions.

function kolmo,data1,pdf,nsample,iplot

;nsample = 100
n1 = double(n_elements(data1))
n2 = double(n_elements(pdf))
s1 = dblarr(nsample)
x1 = data1

x1 = x1(sort(x1))

xmin = min(x1)
xmax = max(x1)

x = xmin + dindgen(nsample)*(xmax-xmin)/double(nsample-1)

for i=0,nsample-1 do begin
if(x(i) ge xmin) then s1(i) = double(n_elements(where(x1 le x(i))))
endfor
s1 = s1/n1

s2=pdf



if(iplot eq 1) then begin
plot,s1
oplot,s2,linestyle=2
endif

D = max(abs(s1-s2))
if(D eq 0.0d0) then return,1
N = n1

x = (sqrt(N) + 0.12d0 + 0.11d0/sqrt(N) )*D

prob = 0
j=1.0d0
suite:
add = (-1.0d0)^(j-1.0d0)*2.0d0*exp(-2.0d0*j^2*x^2)
prob = prob + add
j = j + 1.0d0
if(abs(add) gt 1.0d-5) then goto,suite
return,prob
end