Question

Matlab: When I plot "figure (3)", I would like it to produce three lines/curves instead of data points. Currently, the code will only produce a plot when I use characters and symbols. Please help...

%-------------------------------------------------------------------------------------------------------------%

clear all

close all

clc

xmax=1;

ne=100;

nx=ne+1;

dx=xmax/ne;

dxdx=dx+dx;

dx2=dx*dx;

dt=0.02;

%-------------------------------------------------------------------------------------------------------------%

for i=1:nx

u(i)=0;

bvec(i)=0;

end

u=u';

bvec=bvec';

amat(1,1)=1;

for i=2:nx-1

amat(i,i)=(2/dx2)+(1/dt);

amat(i,i-1)=-(1/dx2);

amat(i,i+1)=-(1/dx2);

end

amat(nx,nx)=1;

av=inv(amat);

for it=1:100

zt(it)=(it-1)*dt;

bvec(1)=-exp(-(zt(it)-0.5)^2/0.03);

for j=2:nx-1

bvect(j)=(u(j)/dt)+(1/2*u(j));

end

bvec(nx)=zt(it)*(sin(4*zt(it)))^4;

u=av*bvec;

for j=1:nx

out(it,j)=u(j);

end

end

%-------------------------------------------------------------------------------------------------------------%

figure(1)

mesh(out)

xlabel('X')

ylabel('Time')

zlabel('Temperature')

title('Temperature as a Function of Time and Space')

%-------------------------------------------------------------------------------------------------------------%

figure(2)

pcolor(out)

xlabel('X')

ylabel('Time')

title('Temperature as a Function of Time and Space')

%-------------------------------------------------------------------------------------------------------------%

figure(3)

for k=1:ne

plot(zt(k),out(k,1),'r*')

hold on

plot(zt(k),out(k,31),'b*')

hold on

plot(zt(k),out(k,61),'g*')

hold on

end

title('Time History of Temperature at Different Locations')

xlabel('Time')

ylabel('Temperature')

legend('x=0.0','x=0.3','x=0.6')

Answer 1

`Hey,

Note: Brother in case of any queries, just comment in box I would be very happy to assist all your queries

%-------------------------------------------------------------------------------------------------------------%

clear all

close all

clc

xmax=1;

ne=100;

nx=ne+1;

dx=xmax/ne;

dxdx=dx+dx;

dx2=dx*dx;

dt=0.02;

%-------------------------------------------------------------------------------------------------------------%

for i=1:nx

u(i)=0;

bvec(i)=0;

end

u=u';

bvec=bvec';

amat(1,1)=1;

for i=2:nx-1

amat(i,i)=(2/dx2)+(1/dt);

amat(i,i-1)=-(1/dx2);

amat(i,i+1)=-(1/dx2);

end

amat(nx,nx)=1;

av=inv(amat);

for it=1:100

zt(it)=(it-1)*dt;

bvec(1)=-exp(-(zt(it)-0.5)^2/0.03);

for j=2:nx-1

bvect(j)=(u(j)/dt)+(1/2*u(j));

end

bvec(nx)=zt(it)*(sin(4*zt(it)))^4;

u=av*bvec;

for j=1:nx

out(it,j)=u(j);

end

end

%-------------------------------------------------------------------------------------------------------------%

figure(1)

mesh(out)

xlabel('X')

ylabel('Time')

zlabel('Temperature')

title('Temperature as a Function of Time and Space')

%-------------------------------------------------------------------------------------------------------------%

figure(2)

pcolor(out)

xlabel('X')

ylabel('Time')

title('Temperature as a Function of Time and Space')

%-------------------------------------------------------------------------------------------------------------%

figure(3)
plot(zt(1:ne),out(1:ne,1),'-r');
hold on;
plot(zt(1:ne),out(1:ne,31),'-b');
hold on;
plot(zt(1:ne),out(1:ne,61),'-g');
title('Time History of Temperature at Different Locations')

xlabel('Time')

ylabel('Temperature')

legend('x=0.0','x=0.3','x=0.6')

​​​​​​​

Kindly revert for any queries

Thanks.