matlab,statistics,goodness-of-fit,exponential-distribution

At 36 values, you have a very small sample set. From the second sentence of Wikipedia's article on the chi-squared test (emphasis added): It is suitable for unpaired data from large samples. Large in this case usually means around at least 100. Read about more assumptions of this test here....

simulation,distribution,exponential-distribution

It's not an error to get zero. With exponential interarrival times and a rate of 3 per hour, the number of occurrences in an hour has a Poisson distribution with λ=3. The probability of getting n outcomes is e-λλn/n! which for n=0 is just under 0.05. In other words, you...

r,recursion,random,exponential-distribution

You are using a simple rejection sampler with two conditions a > 10 & a < 10.2 a+ b > 15 However, the chance of matching both of them is low, i.e. very slow. However, since you are interested in exponential random numbers, we can avoid simulating numbers we would...

events,simulink,exponential-distribution

You've got a couple of choices. In MATLAB, you can generate all samples in advance (i.e. before running the simulation) and use them to create a suitable signal, then use that as an input into the model (using the From Workspace block). Or, if you need to do the sampling...