dnchisq(x, df, lambda) pnchisq(q, df, lambda) qnchisq(p, df, lambda) rnchisq(n, df, lambda)
df
degrees of freedom and non-centrality
parameter lambda
. dnchisq
gives the density, pnchisq
gives the distribution function qnchisq
gives the quantile
function and rnchisq
generates random deviates.
The non-central chi-square distribution with df degrees of freedom and non-centrality parameter λ has density
f(x) = exp(-lambda/2) SUM_{r=0}^infty (lambda^r / 2^r r!) pchisq(x, df + 2r)
dchisq
, dgamma
.