Create a vector z with 1000 elements generated by the rand-function. The generated values must have a mean value of 0.5 (mean(0.5)). And a standard deviation of sqrt(1/100*12), (std(x)).

4 vues (au cours des 30 derniers jours)
So my task is to determine mean of an random vector to be set to 0.5. And the set standard deviation to be sqrt(1/100*12)
  2 commentaires
Adam
Adam le 7 Sep 2018
And what have you done so far. I assume you have searched the Matlab help for functions such as 'rand' and followed the links from there to the other random number generation functions.
Rik
Rik le 28 Juin 2023
What makes you think after almost 5 years that this question is unclear? Please provide an explanation in a comment.
I have removed your flag and will copy the question below.
Create a vector z with 1000 elements generated by the rand-function. The generated values must have a mean value of 0.5 (mean(0.5)). And a standard deviation of sqrt(1/100*12), (std(x)).
So my task is to determine mean of an random vector to be set to 0.5. And the set standard deviation to be sqrt(1/100*12)

Connectez-vous pour commenter.

Réponse acceptée

Cesar Antonio Lopez Segura
Hi all
Here the code:
mu = 0.5;
sigma = 0.3464;
z = mu + randn(1,1000)*sigma
STDcalculated = std( z )
MuCalculated = mean( z )
  3 commentaires
Vetle Normann
Vetle Normann le 7 Sep 2018
Thank you! When I run loop on this script in Matlab STDcalculated and MuCalculated, the results are always close to 0.5 and 0.3463, but not the excact value. But is this as close as possible we get to 0.5 and 0.3464?
Cesar Antonio Lopez Segura
Hi Vetle,
Using this values you can minimize your error:
mu = 0.50329141240781;
sigma = 0.347330944035507;

Connectez-vous pour commenter.

Plus de réponses (1)

Torsten
Torsten le 7 Sep 2018
Modifié(e) : Torsten le 7 Sep 2018
0.5*(a+b) = 0.5
1/12*(b-a)^2 = 0.12
Solve for a and b.
This will give you the interval [a b] for which you must generate uniformly distributed random numbers.
Then you can use the rand-function as
z=a+(b-a)*rand(1000,1)
Best wishes
Torsten.

Catégories

En savoir plus sur Random Number Generation dans Help Center et File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by