how to get the same result using rand

im looking to answer this question: create N = 2 random vectors and each vector with L=10^6 samples

that are uniformly distributed between [-0.5 and 0.5], Plot the histogram with 40

bins of the sum of these two vectors..

so far I am here but i when i check my random numbers it ranges from 0,1 and not (-.5, .5). Can someone else me understand what I am doing wrong.

L=10^6;

a=[-.5 5];

b=[-.5 5];

a=rand(1,L);

b=rand(1,L);

sum=(a+b);

histogram(sum,40)

title('Histogram with 40 bins for sum of the 2 vectors');

Answer 1

[Les Beckham]

The documentation for rand states that it returns values "drawn from the uniform distribution in the interval (0,1)". If you want numbers between -0.5 and +0.5 simply subtract 0.5 from your a and b vectors.

Also, delete these two lines from your code. The don't do anything as you are redefining a and b in the next two lines:

a=[-.5 5];
b=[-.5 5];

[Steven Lord]

FYI the "Random Numbers Within Specified Interval" example on that documentation page shows how to generate numbers on a specific interval using rand.

[Damien]

Thank you for your help!

[Les Beckham]

You are quite welcome.

It is considered courteous in this forum to click "Accept this Answer" on the answer that best answers your question.

Answer 2

[David Hill]

s=sum(rand(2,1e6)-.5);
histogram(s,40)