Undefined function 'mtimes' in line 56

1 次查看（过去 30 天）
Teag
Teag 2023-11-14
评论： Walter Roberson 2023-11-14
Ran in:
Line 56 (M = (m/-dt)-(qdot/(dens*dx*cp))*dx-(h*dx/(dens*dx*cp))*Tinf;) creates a 'mtimes' error and evrything I can find says this has to do with multiplying function handles, but I don't have any function handles anywhere in the code.
cp = 1007;
dens = 1.18;
k = 60;
h = 100;
dx = 0.01;
dt = 0.1;
endTime = 50;
qdot = 1000;
alpha = 3.243*10^-5;
F = alpha * dt / dx^2;
C = 0.05;
Bi = (h*C)/k;
Tinf = 27;
T2 = 20;
T = zeros(4, 5);
Z = dens*dx*cp;
Y = (1+2*F*(2+Bi));
Coef = 2*Bi*F*Tinf;
CoefBottom = 2*Bi*F*T2;
Y2 = 1+4*F;
Q = 1-4*k*Z;
Q2 = 2*qdot*Z*dx;
U = ((-h*dx/Z)-(2*k/Z)-(1/dt));
R = (1+4*F*(1+Bi));
numTimeSteps = ceil(endTime / dt);
for t = 1:numTimeSteps
Tnew = T;
A = [U k/Z 0 0 0 k/Z 0 0 0 0 0 0 0 0 0 0 0 0 0 0,%1
k*Z Q k*Z 0 0 0 2*k*Z 0 0 0 0 0 0 0 0 0 0 0 0 0,%2
0 k*Z Q k*Z 0 0 0 2*k*Z 0 0 0 0 0 0 0 0 0 0 0 0,%3
0 0 k*Z Q k*Z 0 0 0 2*k*Z 0 0 0 0 0 0 0 0 0 0 0,%4
0 0 0 k/Z U 0 0 0 0 k/Z 0 0 0 0 0 0 0 0 0 0,%5
-F 0 0 0 0 Y -2*F 0 0 0 0 -F 0 0 0 0 0 0 0 0,%6
0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0 0 0 0 0 0 0,%7
0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0 0 0 0 0 0,%8
0 0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0 0 0 0 0,%9
0 0 0 0 -F 0 0 0 -2*F Y 0 0 0 0 -F 0 0 0 0 0,%10
0 0 0 0 0 -F 0 0 0 0 Y -2*F 0 0 0 0 -F 0 0 0,%11
0 0 0 0 0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0 0,%12
0 0 0 0 0 0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0,%13
0 0 0 0 0 0 0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0,%14
0 0 0 0 0 0 0 0 0 -F 0 0 0 -2*F Y 0 0 0 0 -F,%15
0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 0 R -2*F 0 0 0,%16
0 0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 -F Y -F 0 0,%17
0 0 0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 -F Y -F 0,%18
0 0 0 0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 -F Y -F,%19
0 0 0 0 0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 -2*F R];%20
m = T(1,1);
n = T(1,5);
M = (m/-dt)-(qdot/(dens*dx*cp))*dx-(h*dx/(dens*dx*cp))*Tinf;
N = (n/-dt)-(qdot/(dens*dx*cp))*dx-(h*dx/(dens*dx*cp))*Tinf;
B = [M,
-T(1,2)-Q2,
-T(1,3)-Q2,
-T(1,4)-Q2,
N,
Coef+T(2,1),
T(2,2),
T(2,3),
T(2,4),
Coef+T(2,5),
Coef+T(1,3),
T(3,2),
T(3,3),
T(3,4),
Coef+T(3,5),
2*CoefBottom+T(1,4),
CoefBottom+T(4,2),
CoefBottom+T(4,3),
CoefBottom+T(4,4),
2*CoefBottom+T(4,5)];
C = A^-1 * B;
Tnew = [C(1) C(2) C(3) C(4) C(5),
C(6) C(7) C(8) C(9) C(10),
C(11) C(12) C(13) C(14) C(15),
C(16) C(17) C(18) C(19) C(20)];
T = Tnew;
h = imagesc(T);
title(['Time = ' num2str(t*dt) ' ']);
colorbar;
axis equal;
xlabel('X-axis');
ylabel('Y-axis');
drawnow;
end
Operator '*' is not supported for operands of type 'matlab.graphics.primitive.Image'.

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2023-11-14
h = 100;
h is numeric.
M = (m/-dt)-(qdot/(dens*dx*cp))*dx-(h*dx/(dens*dx*cp))*Tinf;
You do calculations with h inside the loop.
h = imagesc(T);
But now h is the handle to the image() object that is created by imagesc().
Next iteration will try to multiply the handle to the image object, by numeric values... but that is going to fail.

更多回答（1 个）

atharva
atharva 2023-11-14
Hey teag,
I understand that you are facing the error "Operator '*' is not supported for operands of type 'matlab.graphics.primitive.Image'."
The error you are encountering is due to the fact that while looping you are trying to add a value to the handle h, which is already an image object created by the imagesc function. To fix this, you should use a different variable for the temperature distribution plot and avoid overwriting it with the image handle.
Here is the code you can try
cp = 1007;
dens = 1.18;
k = 60;
h = 100;
dx = 0.01;
dt = 0.1;
endTime = 50;
qdot = 1000;
alpha = 3.243*10^-5;
F = alpha * dt / dx^2;
C = 0.05;
Bi = (h*C)/k;
Ttinf = 27;
T2 = 20;
T = zeros(4, 5);
Z = dens*dx*cp;
Y = (1+2*F*(2+Bi));
Coef = 2*Bi*F*Ttinf;
CoefBottom = 2*Bi*F*T2;
Y2 = 1+4*F;
Q = 1-4*k*Z;
Q2 = 2*qdot*Z*dx;
U = ((-h*dx/Z)-(2*k/Z)-(1/dt));
R = (1+4*F*(1+Bi));
numTimeSteps = ceil(endTime / dt);
for t = 1:numTimeSteps
Tnew = T;
A = [U k/Z 0 0 0 k/Z 0 0 0 0 0 0 0 0 0 0 0 0 0 0,%1
k*Z Q k*Z 0 0 0 2*k*Z 0 0 0 0 0 0 0 0 0 0 0 0 0,%2
0 k*Z Q k*Z 0 0 0 2*k*Z 0 0 0 0 0 0 0 0 0 0 0 0,%3
0 0 k*Z Q k*Z 0 0 0 2*k*Z 0 0 0 0 0 0 0 0 0 0 0,%4
0 0 0 k/Z U 0 0 0 0 k/Z 0 0 0 0 0 0 0 0 0 0,%5
-F 0 0 0 0 Y -2*F 0 0 0 0 -F 0 0 0 0 0 0 0 0,%6
0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0 0 0 0 0 0 0,%7
0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0 0 0 0 0 0,%8
0 0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0 0 0 0 0,%9
0 0 0 0 -F 0 0 0 -2*F Y 0 0 0 0 -F 0 0 0 0 0,%10
0 0 0 0 0 -F 0 0 0 0 Y -2*F 0 0 0 0 -F 0 0 0,%11
0 0 0 0 0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0 0,%12
0 0 0 0 0 0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0 0,%13
0 0 0 0 0 0 0 0 -F 0 0 0 -F Y2 -F 0 0 0 -F 0,%14
0 0 0 0 0 0 0 0 0 -F 0 0 0 -2*F Y 0 0 0 0 -F,%15
0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 0 R -2*F 0 0 0,%16
0 0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 -F Y -F 0 0,%17
0 0 0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 -F Y -F 0,%18
0 0 0 0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 -F Y -F,%19
0 0 0 0 0 0 0 0 0 0 0 0 0 0 -2*F 0 0 0 -2*F R];%20
m = T(1,1);
n = T(1,5);
M = ((m/-dt)-(qdot/(dens*dx*cp))*dx-(h*dx/(dens*dx*cp)))*Ttinf;
N = ((n/-dt)-(qdot/(dens*dx*cp))*dx-(h*dx/(dens*dx*cp)))*Ttinf;
B = [M,
-T(1,2)-Q2,
-T(1,3)-Q2,
-T(1,4)-Q2,
N,
Coef+T(2,1),
T(2,2),
T(2,3),
T(2,4),
Coef+T(2,5),
Coef+T(1,3),
T(3,2),
T(3,3),
T(3,4),
Coef+T(3,5),
2*CoefBottom+T(1,4),
CoefBottom+T(4,2),
CoefBottom+T(4,3),
CoefBottom+T(4,4),
2*CoefBottom+T(4,5)];
C = A^-1 * B;
Tnew = [C(1) C(2) C(3) C(4) C(5),
C(6) C(7) C(8) C(9) C(10),
C(11) C(12) C(13) C(14) C(15),
C(16) C(17) C(18) C(19) C(20)];
T = Tnew;
temp = imagesc(T);
title(['Time = ' num2str(t*dt) ' ']);
colorbar;
axis equal;
xlabel('X-axis');
ylabel('Y-axis');
drawnow;
end
I hope this helps!

类别

在 Help Center 和 File Exchange 中查找有关 Startup and Shutdown 的更多信息

标签

产品


版本

R2023b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by