Equal probability bins

Any clues on how to create equal probability vs equal length bins for a chi2 test for an exponential distribution? Your help will be appreciated!

Answer 1

[Tom Lane]

The "edges" variable here seems to be what you need if you want 6 bins and your exponential distribution has mean 5.5:

>> n = 6;
>> edges = expinv((0:n)/n,5.5)
edges =
         0    1.0028    2.2301    3.8123    6.0424    9.8547       Inf
>> diff(expcdf(edges,5.5))
ans =
    0.1667    0.1667    0.1667    0.1667    0.1667    0.1667