How do I generate numbers from an Exponential Distribution within Min and Max values?

How to generate random numbers with the exponential distribution applied, and also given a minimum value of 0.5, and a maximum value of 4.3, the mean is 1.5?

How do I add the maximum to the following?

pd = makedist('Exponential','mu', 1.5);

r=0;

while r<0.5

r=random(pd);

end

Answer 1

[Star Strider]

Use the truncate function —

pd = makedist('Exponential','mu', 1.5);
t = truncate(pd, 0.5, 4.3);

r = random(t,10000,1);

figure
histogram(r,100)

.

[John D'Errico]

+1. Truncate is the correct solution, of course. It will sometimes be vastly more efficient compared to rejection schemes too, since random does not need to throw away a significant fraction of the generated samples.

[Star Strider]

@John D'Errico — Thank you!

Answer 2

[Vishnu]

Hi Sean Sarran,

Simply insert a "or" statement in the while loop condition itself to apply a maximum value of 4.3.

Consequently, this is the whole code:

pd = makedist('Exponential', 'mu', 1.5);

r = 0;

while r < 0.5 || r > 4.3
    r = random(pd);
end

Answer 3

[Torsten]

pd = makedist('Exponential','mu', 1.5);
n = 100;
lb = 0.5;
ub = 4.3;
rv = zeros(n,1);
i = 0;
while i < n
    r = random(pd);
    if r >= lb & r <= ub 
        i = i+1;
        rv(i) = r;
    end 
end
rv

rv = 100×1

3.7779 1.5435 0.8186 2.5542 3.0388 2.1058 1.9611 1.3722 0.9059 3.2783