please help me in this program something wrong in integration

n= input('enter the value of a ');

g= input('enter the value of index ');

z=n-1;

e=exp(1);

syms t;

f= (e^(-t)).*(t^(z));

y=int(f,t,0,inf)

y1=int(f,t,0,g)

y2=y-y1

b= input ('enter the value of b ');

x=g:200;

l = pdf('gam',x,n,b);

plot(x,l,'green')

hold on;

p= ((x.^z).* (e.^(-(x/b))))/((y2*(b.^n))*y1);

plot(x,p,'blue')

there is something wrong with integral y1,any help will be welcomed,

[Jan]

"Something is wrong" is not a helpful description of the problem. It is better to post either the complete error message or explain the differences between the results and your expectations.

Please follow the "Aubout MATLAB Answers" link to learn how to format code in the forum.

Answer 1

[Andrei Bobrov]

p = input ('enter the parametrs p in form: [n, b, g], here n < b && n > 0 && g < 200 => ');
f = @(t)exp(-t).*t.^(p(1) - 1);
A = cellfun(@(x)quadgk(f,x{:}),{{0,p(3)},{p(3) inf}});
x=p(3):200;
l = pdf('gam',x,p(1),p(2));
p1 =   x.^(p(1)-1).*    exp(-x/p(2) )      /  (A(2)*p(2).^p(1)*A(1));
plot(x,l,'green')
hold on;
plot(x,p1,'blue')