Scythe-1.0.3
double scythe::dpois ( unsigned int  x,
double  lambda 
) [inline]

The Poisson density function.

Computes the value of the Poisson probability density function with expected number of occurrences lambda, at the desired quantile x.

It is also possible to call this function with a Matrix of doubles as its first argument. In this case the function will return a Matrix of doubles of the same dimension as x, containing the result of evaluating this function at each value in x, given the remaining fixed parameters. By default, the returned Matrix will be concrete and have the same matrix_order as x, but you may invoke a generalized version of the function with an explicit template call.

Parameters:
xThe desired integer quantile.
lambdaThe expected positive number of occurrences.
See also:
ppois(unsigned int x, double lambda)
rng::rpois(double lambda)
Exceptions:
scythe_invalid_arg(Level 1)

References exp(), log(), and SCYTHE_CHECK_10.