MATLAB: How can i plot f(i),g(i),h(i) in one figure(i)

Question

I want to plot each three diagrams in one figure

Answer 1

Use the subplot function.

Your loop becomes:

figure(1)
for i = 1:3
    subplot(3,1,i)
       . . .
    plot(x,f(i),'-b', ... )
       . . .
end

to get 3 stacked plots in one figure. Other configurations are possible. See the documentation on subplot for details.