How to generate a matrix with random numbers between 0 and 1 and mean of the distribution is unspecified.
1 view (last 30 days)
Show older comments
Every time I generate matrix with random numbers between 0 and 1, mean of the generated distribution is different.
1 Comment
Walter Roberson
on 3 Jun 2022
Are you asking how to deliberately generate a different mean each time? If so then I suggest generate random coefficients for a beta distribution.
Answers (2)
Torsten
on 3 Jun 2022
If you choose the number of random numbers large enough, their mean should approach 0.5:
n = 20000;
y = rand(n,1);
ym = mean(y)
If you want the same numbers ( and thus the same mean ) in each run, use
rng('default')
0 Comments
John D'Errico
on 3 Jun 2022
You need to understand the difference between a sample mean, and the population mean.
x = rand(1,100);
mean(x)
This is a random SAMPLE, so at best, it will only have a mean near the population mean for that uniform random number generator, which is theoretically 0.5 exactly.
With larger sample size, the sample mean approaches the population mean, but that is only an asymptotic thing.
mean(rand(1,1e6))
If you really want a sample with the sample mean EXACTLY the same as the population mean, then your sample is not as easy to generate. However, it can be done using Roger Stafford's randfixedsum, as found on the file exchange. Better here is probably to just understand the difference.
0 Comments
See Also
Categories
Find more on Random Number Generation in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!