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

I want to plot each three diagrams in one figure

Answer 1

[Star Strider]

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.

[MA]

please write whole program,i don't understand

[Star Strider]

It would have been easier if you had attached your code as something I could copy and paste. I went to the effort of typing it in, troubleshooting it when your initial code didn’t work, and correcting it.

This works as you wrote it, with my changes to get it to run:

syms x
f = sym(zeros(3,1));
g = sym(zeros(3,1));
h = sym(zeros(3,1));
f(1) = sin(x) + cos(x);
f(2) = tan(x);
f(3) = 1/(1+x);
g(1) = sin(2*x);
g(2) = cos(x)^2;
g(3) = log(x);
h(1) = x^3+sin(x^3);
h(2) = tan(x)^2;
h(3) = x;
ff = matlabFunction(f);         % Convert symbolic vector to function
gf = matlabFunction(g);         % Convert symbolic vector to function
hf = matlabFunction(h);         % Convert symbolic vector to function
x = 0:0.5:10;
fgh = [ff(x)' gf(x)' hf(x)'];   % Refer to this matrix in the loop

figure(1)                       % Create figure object

for i = 1:3
    subplot(3,1,i)              % Plot first of stacked subolots
    plot(x, fgh(:,i+[0 3 6]))   % Plot each function as function of ‘x’
    axis equal
    grid on
    xlabel('x')
    title( sprintf('Plot of f_{%d}, g_{%d}, h_{%d}', [i i i]))
end

To understand the changes I made (and the reasons) see the documentation on matlabFunction to understand those lines, and cell to understand my use of the curly braces ‘{}’ in my fgh assignment array creation.

[MA]

it's absolutly correct but i want to put f(1),g(1) and h(1) on one diagram not to put f(1),f(2) and f(3) in one,and others similarly

[Star Strider]

I edited the code in my previous comment rather than re-post different code here. It should now do what you want.

The plots look strange because you have ‘axis equal’ in your plot statements. I left that in because it was in your original code. (I took it out when I ran it to be sure everything was plotting correctly.)

[MA]

thank you so much

[Star Strider]

My pleasure!