Well, presumably you have the pmf and can create a matrix of the form:
(where mypmf is your pmf)
x <- seq_len(1000) ## or whatever your discrete support sorted in
increasing order
## for individual quantile q:
max(x[cumsum(mypmf(x)) <= q] )
## This probably could be vectorized for a vector of quantiles . I
leave that to others both cleverer and more motivated than I.
Cheers,
Bert
Bert Gunter
"Data is not information. Information is not knowledge. And knowledge
is certainly not wisdom."
-- Clifford Stoll
On Thu, Jun 25, 2015 at 8:59 AM, L... L... <mar.lamack at hotmail.com>
wrote:> I thank all for your reply. My question was not well formulated.
> I will do it again:
> Suppose that the random variable X is discrete with probability mass
function (pmf) F (binomial, poisson, ....) not necessarily available in R.
> Is there a general method to get the quantiles (as qbinom, qpois, .....) or
which is the method(s) used to get the quantiles (used in qbinom, qpois, .....)?
> Regards
> ML
> [[alternative HTML version deleted]]
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