Is it possible to calculate partial sums in R?
I have the equation:
Px = (k / x) * SUM_{from j >= x to infinity} Pj x=1,2,3,...
where k is a parameter, Pj is the Poisson probability, and x is a rank.
(This is for rank-frequency data.) In other words, the frequency of an
entity at rank x depends on the sum of frequencies of all entities at
ranks j > x.
Many thanks,
Andrew Wilson
Partial Sums
2 messages · Dr Andrew Wilson, Peter Dalgaard
Dr Andrew Wilson <eia018 at comp.lancs.ac.uk> writes:
Is it possible to calculate partial sums in R?
I have the equation:
Px = (k / x) * SUM_{from j >= x to infinity} Pj x=1,2,3,...
where k is a parameter, Pj is the Poisson probability, and x is a rank.
(This is for rank-frequency data.) In other words, the frequency of an
entity at rank x depends on the sum of frequencies of all entities at
ranks j > x.
With some restriction on k and the Poisson intensity lambda, I presume? How about k/x * (1-ppois(x-1,lambda)) or am I overlooking something??
O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907