n=20000
x=randomu(seed,n)*360.
y=randomu(seed,n)*180.-90.
st=systime(1)
for i = 0 , n-2 do begin
  a=geogdist(pos1=[x(i),y(i)],pos2=[x(i+1),y(i+1)])
endfor
en=systime(1)
print,(en-st)
print,(en-st)*2122200/float(n)
end