how to plot two m.file in one plot

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

Answer 1

[Dyuman Joshi]

Call both the PDEs in a new script/function and plot accordingly.

[br]

i write it like this but it's not work, and also it's not seems to be right

kp0=140270;
Eap=43900;
kd0=0.355;
Ead=17400;
T=333;
kp=kp0*exp(-Eap/(8.314*T));
kd=kd0*exp(-Ead/(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
xlabel('radius');
ylabel('concentration');

[Dyuman Joshi]

"i write it like this but it's not work, and also it's not seems to be right"

Please specify how it is not working.

Why does it not seem right?

[br]

it's give me an error

[Dyuman Joshi]

Please share -

1 - the full error message i.e. all of the red text.

2 - the PDE files (eqn111, initial111 and eqn11, initial11). Use the paperclip button to attach.

[br]

Error using pdepe

The entries of XMESH must be strictly increasing.

Error in runnnn (line 11)

for u=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);

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;
-----------------------------------------------------------------------------

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)
value=0.036405;

[Torsten]

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;
Ead=17400;
T=333;
kp=kp0*exp(-Eap/(8.314*T));
kd=kd0*exp(-Ead/(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
xlabel('radius');
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]

thanks a lot

Answer 2

[Sulaymon Eshkabilov]

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]

thanks a lot, but each parameter x and u are in differant m.file how to combine them?