Extracting Data from Script

I would like to know how to get the data plotted by the script I have made. It was the solution of a pdepe problem. Thank you

[Olawale Ikuyajolu]

save function?

[Adrian Oblena]

I have this code and I want to get the data used to plot once you run my script. Below is my script.

function AdvDiff

m=0;
x=linspace(0,1,10);
t=linspace(0,1,10);

sol = pdepe(m,@AdvDiffpde,@AdvDiffic,@AdvDiffbc,x,t);
% Extract the first solution component as u.
u = sol(:,:,1);

% A surface plot
surf(x,t,u) 
title('Advection Diffusion')
xlabel('Distance,x')
ylabel('Time,t')
zlabel('Concentration,C')

% A solution profile
figure
plot(x,u(end,:))
title('Advection Diffusion')
xlabel('Distance,x')
ylabel('Concentration,C')
grid on
axis tight
end

%PDE for Advection Diffusion Equation
function [c,f,s] = AdvDiffpde(x,t,u,DuDx)
c = 1;
f = DuDx;
s = -u*DuDx;
end

%Initial Condition Function 
function u0 = AdvDiffic(x)
u0 = exp(-x);
end

%Boundary Condition Functions
function [pl,ql,pr,qr] = AdvDiffbc(xl,ul,xr,ur,t)
pl = ul+t-1;
ql = 0;
pr = ur-(1-t)/exp(1);
qr = 0;
end

[Olawale Ikuyajolu]

Do you want to get x and u?

[Adrian Oblena]

I want to get u(x,t)

for every x and t

Answer 1

[KALYAN ACHARJYA]

Assign those varibles as output arguments

function [u,data2,x_data]=AdvDiff
m=0;
x=linspace(0,1,10);
t=linspace(0,1,10);
sol = pdepe(m,@AdvDiffpde,@AdvDiffic,@AdvDiffbc,x,t);
% Extract the first solution component as u.
u = sol(:,:,1);
% A surface plot
surf(x,t,u) 
title('Advection Diffusion')
xlabel('Distance,x')
ylabel('Time,t')
zlabel('Concentration,C')
% A solution profile
figure
data2=u(end,:);
plot(x,data2);
title('Advection Diffusion')
xlabel('Distance,x')
ylabel('Concentration,C')
grid on
axis tight
end

Call the dunctions with output arguments (Make all variable as output arguments, those data you needed in the currect working directory)

Example:

>> [u,data2,x_data]=AdvDiff
u =

    1.0000    0.8948    0.8007    0.7165    0.6412    0.5738    0.5134    0.4594    0.4111    0.3679
    0.8889    0.8584    0.8154    0.7624    0.7018    0.6356    0.5652    0.4908    0.4119    0.3270
    0.7778    0.7671    0.7441    0.7092    0.6632    0.6067    0.5401    0.4642    0.3793    0.2861
    0.6667    0.6657    0.6528    0.6279    0.5911    0.5427    0.4832    0.4131    0.3334    0.2453
    0.5556    0.5612    0.5552    0.5376    0.5083    0.4677    0.4161    0.3544    0.2834    0.2044
    0.4444    0.4560    0.4562    0.4451    0.4229    0.3899    0.3466    0.2938    0.2323    0.1635
    0.3333    0.3509    0.3573    0.3527    0.3375    0.3121    0.2771    0.2331    0.1812    0.1226
    0.2222    0.2461    0.2589    0.2610    0.2529    0.2351    0.2082    0.1730    0.1305    0.0818
    0.1111    0.1418    0.1614    0.1704    0.1695    0.1592    0.1404    0.1138    0.0803    0.0409
   -0.0000    0.0381    0.0648    0.0810    0.0874    0.0847    0.0738    0.0554    0.0305         0

data2 =
   -0.0000    0.0381    0.0648    0.0810    0.0874    0.0847    0.0738    0.0554    0.0305         0
x_data =
         0    0.1111    0.2222    0.3333    0.4444    0.5556    0.6667    0.7778    0.8889    1.0000

Now output aruguments are avalible in workspace, thease variable are avalible outside if the function also

See the function file, if you execute the main code without function file, all varible are avalible in workspace. Suggested tho see the documentation (Matlab Function Declaration) and another way define those variables as global variables, please go through this.

Any issue let me know

[Adrian Oblena]

This is really a great help. Thank you very much.