Histogram with added density function

Hey guys,

I am new to Matlab and have a simple question about plots and histograms.

I'd need to create four subplots with each containing a histogram. On every histogram the number of datapoints increases. first histo: 5 datapoints, second histo: 50 datapoints, thrid histo: 500 dp , fourth histo: 5000 dp.

• The datapoints should have an exponential distribution with mean value = 1 (I used exprnd command).
• Additionally I need to add a cdf density function to each subplot. (distribution parameter can also be 1)

clc; 
clear all; 
close all; 
rng('default'); 

datapoints5 = exprnd(1 , [5,1]);
datapoints50 = exprnd(1 , [50,1]);
datapoints500 = exprnd(1 , [500,1]);
datapoints5000 = exprnd(1 , [5000,1]);

plot(cdf,histogram(datapoints5000));
histogram(datapoints500); 
histogram(datapoints50);
histogram(datapoints5); 

Hope somebody can help me figure this out,

Best regards,

Alex

Answer 1

[Ameer Hamza]

Try this:

clc; 
close all; 
rng('default');

datapoints{1} = exprnd(1 , [5,1]);
datapoints{2} = exprnd(1 , [50,1]);
datapoints{3} = exprnd(1 , [500,1]);
datapoints{4} = exprnd(1 , [5000,1]);

for i=1:numel(datapoints)
    ax = subplot(2,2,i);
    histogram(datapoints{i});
    dist = fitdist(datapoints{i}, 'Exponential');
    x_points = linspace(0, ax.XLim(2), 100);
    Pdf = pdf(dist, x_points);
    Cdf = cdf(dist, x_points);
    yyaxis right
    hold on
    plot(x_points, Pdf, 'r', 'LineWidth', 2, 'DisplayName', 'PDF');
    plot(x_points, Cdf, 'b', 'LineWidth', 2, 'DisplayName', 'CDF');
    legend
end

Result: