CDF for Loglogistic distribution

Zhengpu Chen · Apr 13, 2022 · 1.9K views
Question
What is the Cumulative Distribution Function for Loglogistic distribution? I only found the Probability Density Function in the following link: https://www.mathworks.com/help/stats/loglogistic-distribution.html.  
Expert Answer
Profile picture of John Michell
John Michell PhD Expert
Answered Aug 11, 2026
Hello ,
 
They are equivalent. In Matlab
cdf =               e^z / (1+e^z)            % the missing one
pdf = (1/(sigma*x))*e^z / (1+e^z)^2
where
z = (log(x)-mu)/sigma

When you make the substitution (as mentioned in wikipedia, where they use s in place of sigma)

beta = 1/sigma        e^mu = alpha
then
e^z = (x/alpha)^beta

and for wiki,

cdf =              (x/alpha)^beta)   /(1+(x/alpha)^beta) 
pdf = (beta/alpha)*(x/alpha)^(beta-1)/(1+(x/alpha)^beta)^2

 

100% Run Guarantee 3-Hour Fast-Track Delivery

Need a Custom Version or Complete Simulation for This Problem?

Our 500+ PhD engineers build, debug, and optimize working MATLAB scripts and Simulink (.slx) models tailored to your exact assignment rubrics with zero plagiarism.

Tested on MATLAB R2024b / R2026a
Turnitin 0% Plagiarism Report
Free 7-Day Revisions Guarantee
Have a different question? Ask here

Get a Free Consultation or a Sample Assignment Review!