Generate a random number with max, min and mean (average) in Matlab

Question

I need to generate random numbers with following properties.

• Min must be 1
• Max must be 9
• Average (mean) is 6.00 (or something else)

Answer 1

Here is an algorithm with a loop to reach a required mean xmean (with required precision xeps) by regenerating a random number from one half of a vector to another according to mean at current iteration. With my tests it reached the mean pretty quick.

n = 100;
xmean = 6;
xmin = 1;
xmax = 9;
xeps = 0.01;
x = randi([xmin xmax],n,1);
while abs(xmean - mean(x)) >= xeps
    if xmean > mean(x)
        x(find(x < xmean,1)) = randi([xmean xmax]);
    elseif xmean < mean(x)
        x(find(x > xmean,1)) = randi([xmin xmean]);
    end
end

x is the output you need.