poissfit

Poisson parameter estimates

Syntax

lambdahat = poissfit(data)
[lambdahat,lambdaci] = poissfit(data)
[lambdahat,lambdaci] = poissfit(data,alpha)


Description

lambdahat = poissfit(data) returns the maximum likelihood estimate (MLE) of the parameter of the Poisson distribution, λ, given the data data.

[lambdahat,lambdaci] = poissfit(data) also gives 95% confidence intervals in lambdaci.

[lambdahat,lambdaci] = poissfit(data,alpha) gives 100(1 - alpha)% confidence intervals. For example alpha = 0.001 yields 99.9% confidence intervals.

The sample mean is the MLE of λ.

$$\widehat{\lambda }=\frac{1}{n}{\displaystyle \sum _{i=1}^n{x}_i}$$

Examples

r = poissrnd(5,10,2);
[l,lci] = poissfit(r)
l =
    7.4000    6.3000
lci =
    5.8000    4.8000
    9.1000    7.9000

Version History

Introduced before R2006a