# how to plot two m.file in one plot

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br on 18 Feb 2024
Commented: br on 19 Feb 2024
i have two PDE each one i calculated in m.file, but i want to draw the output of first one as x, and the second as y
how can i do that

Dyuman Joshi on 18 Feb 2024
Call both the PDEs in a new script/function and plot accordingly.
Torsten on 18 Feb 2024
Please include the complete code with error message that demonstrates the problem you have.
The functions you provided don't suffice and some are duplicates.
kp0=140270;
Eap=43900;
kd0=0.355;
T=333;
kp=kp0*exp(-Eap/(8.314*T));
m=2;
t=linspace(0,3600,1000);
u=linspace(0.036405,111.3494528,1000);
x=linspace(0,0.036405,1000);
x1=pdepe(m,@(x,t,u,DuDx)eqn111(x,t,u,DuDx,T),@initial111,@(xl,ul,xr,ur,t)bc111(xl,ul,xr,ur,t,kp,kd),u,t);
u1=pdepe(m,@(x,t,u,DuDx)eqn11(x,t,u,DuDx,T),@initial11,@(xl,ul,xr,ur,t)bc11(xl,ul,xr,ur,t,kp,kd),x,t);
t_indices = find(t >= 0 & t <= 3600);
figure
hold on
for j = t_indices
plot(x1(j,:),u(j,:));
hold off
end
ylabel('concentration');
function [c,f,s]=eqn111(x,t,u,DuDx,T)
c=1;
f=(1.34*10^-7)*exp(-16000/(8.314.*T))*exp(-(0.57*1.225+0.43*1.005*0.524)/(0.57*2.91*(-8.675+T)+0.43*0.5*(-205+T)))*DuDx;
s=0;
end
%----------------------------------------------------------------------------------------
function value=initial11(x)
value=0;
end
%-----------------------------------------------------------------------------
function [c,f,s]=eqn11(x,t,u,DuDx,T)
c=1;
f=(1.34*10^-6)*exp(-16000/(8.314.*T))*exp(-(0.57*1.225+0.43*1.005*0.524)/(0.57*2.91*(-8.675+T)+0.43*0.5*(-205+T)))*DuDx;
s=0;
end
%------------------------------------------------------------------------------
function value=initial11(u)
Function 'initial11' has already been declared within this scope.
value=0.036405;
end
br on 19 Feb 2024
thanks a lot

### More Answers (1)

Sulaymon Eshkabilov on 18 Feb 2024
use plot(x, y), e.g.:
x = [-5:5;2*(-5:5); 3*(-5:5)];
y = [3*x.^2+3*x-3; -5*x.^2+5*x-15; -2*x.^2-3*x-13;];
plot(x(1,:),y(1,:), 'ro-', x(2,:),y(2,:), 'kp:', x(3,:),y(3,:), 'b--', 'LineWidth', 2)
grid on
xlabel ('x')
ylabel ("y(x)")
legend('Set 1', 'Set 2', 'Set 3', 'Location', 'Best')
br on 18 Feb 2024
thanks a lot, but each parameter x and u are in differant m.file how to combine them?

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