I am trying to create a script which draws a graph of gamma distribution with a fixed value of shape and a varied value of scale factor. I have written this script however, the graph it plots is completely blank. Any help would be greatly appreciated

 fprintf('You have choosen 1: Gamma distribution with a fixed value of k with an array of theta values \n');
   xmin=input('Please enter an minimum value for x : ');
    xmax=input('Please enter an maximum value for x : ');
    xinc=input('Please enter an increment value for x : ');
    thetamin=input('Please enter an minimum value for the scale factor, k: \n');
    thetamax=input('Please enter an maximum value for the scale factor, k: \n');
    thetainc=input('Please enter an increment value for the scale factor, k: \n');
    k=input('Please enter a value for the constant, shape factor, theta: \n');
    hold on
for x = xmin : xinc : xmax 
for k = thetamin : thetainc : thetamax;
     a = (x.^(k-1));
 b = (exp(-x/theta));
d = ((theta^k)*gamma(k));
f = (a*b)/d;
plot(x ,f);
 end 
 end 
end

Answer 1

[Thorsten]

You just plot a single value.