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Function Reference: poissinv

statistics: x = poissinv (p, lambda)

Inverse of the Poisson cumulative distribution function (iCDF).

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

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

Input arguments must be double or single; integer, logical, and character arrays are rejected. MATLAB accepts a character array and evaluates it at the character codes, which Octave deliberately does not, since a character array is an integer type and integers are refused too.

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

Source Code: poissinv

Plot various iCDFs from the Poisson distribution

 p = 0.001:0.001:0.999;
 x1 = poissinv (p, 13);
 x2 = poissinv (p, 4);
 x3 = poissinv (p, 10);
 plot (p, x1, '-b', p, x2, '-g', p, x3, '-r')
 grid on
 ylim ([0, 20])
 legend ({'λ = 1', 'λ = 4', 'λ = 10'}, 'location', 'northwest')
 title ('Poisson iCDF')
 xlabel ('probability')
 ylabel ('values in x (number of occurrences)')
plotted figure