random vector (1,10)

hi,

im tring to make a vector size (1,10) who has random integers between 1 to a,

( but only round numbers )

v= a-1 .* round(rand (1,10) +1;

[Walter Roberson]

ceil(something * rand(size stuff)) + somevalue

Answer 1

[Stephen23]

ceil(a*rand(1,10))

Often beginners think of using round for something like this, but the usual algorithm they use has nasty end-effects, where the first and last values have half the probability of any other number.

ceil avoids this.

[Walter Roberson]

What Stephen mentions is important for fair weighting. It is common to use round() in such cases, even amonst people who have programmed for decades but do not have particular background in probability necessary to be know to always be really thorough about cross-checking that the code really does match the probability distribution required.

See for example https://www.mathworks.com/matlabcentral/answers/246999-probability-1-2-with-matlab-random-number-generators in which I explore how difficult it is to really get 50% probability in MATLAB.

Why does it matter? Well read https://www.nytimes.com/interactive/2018/05/03/magazine/money-issue-iowa-lottery-fraud-mystery.html

Answer 2

[Steven Lord]

Use the randi function.