Why does MATLAB generate identical random values after re-opening the program?

I run the code below

y = rand(1,5)

and I get the following values:

0.8147    0.9058    0.1270    0.9134    0.6324

I close MATLAB and reopen it again and enter the same code and I get the same random values. Why does MATLAB create the exact same numbers each time?

[Stephen23]

"Why does MATLAB create the exact same numbers each time?"

Because:

• computers can't really generate random numbers.
• that is exactly what MATLAB is specified to do:

https://www.mathworks.com/help/matlab/math/why-do-random-numbers-repeat-after-startup.html

Answer 1

[Rightia Rollmann]

I set rng to 'default', so I expected that it'll generate new random numbers after re-running MATLAB, but that is not the case. Why? How can I get MATLAB to generate new random numbers after re-opening it?

[Guillaume]

Follow the link in Stephen's comment to get the answer to your question, or do what Madhan told you.

Also, don't use the answer box for comments.

[Stephen23]

"I set rng to 'default', so I expected that it'll generate new random numbers after re-running MATLAB..."

The rng documentation explains that the 'default' option as "This way, the same random numbers are produced as if you restarted MATLAB. The default settings are the Mersenne Twister with seed 0." Clearly with the same seed it will generate exactly the same values each time. That is what it is specified to do!

Answer 2

[madhan ravi]

hi, see the link below:

https://www.mathworks.com/help/matlab/ref/rng.html

[madhan ravi]

did you try

rng('shuffle')