### Function Reference: `poisscdf`

statistics: p = poisscdf (x, lambda)
statistics: p = poisscdf (x, lambda, `"upper"`)

Poisson cumulative distribution function (CDF).

For each element of x, compute the cumulative distribution function (CDF) of the Poisson distribution with rate parameter lambda. The size of p is the common size of x and lambda. A scalar input functions as a constant matrix of the same size as the other inputs.

`p = poisscdf (x, lambda, "upper")` computes the upper tail probability of the Poisson distribution with parameter lambda, at the values in x.

Further information about the Poisson distribution can be found at https://en.wikipedia.org/wiki/Poisson_distribution

See also: poissinv, poisspdf, poissrnd, poissfit, poisslike, poisstat

Source Code: poisscdf

### Example: 1

     ## Plot various CDFs from the Poisson distribution
     x = 0:20;
     p1 = poisscdf (x, 1);
     p2 = poisscdf (x, 4);
     p3 = poisscdf (x, 10);
     plot (x, p1, "*b", x, p2, "*g", x, p3, "*r")
     grid on
     ylim ([0, 1])
     legend ({"λ = 1", "λ = 4", "λ = 10"}, "location", "southeast")
     title ("Poisson CDF")
     xlabel ("values in x (number of occurences)")
     ylabel ("probability")