Error in execution?

clear 
clc

x=[0 2 4 6 8];
y=[0 2 4 6 8];
T=[100 90 80 70 60; 85 64.49 53.50 48.15 50; 70 48.90 38.43 35.03 40; 55 38.78 30.39 27.07 30; 40 35 30 25 20];
x_target=4;
y_target=3.2;

*T_target=interp2(x,y.T,x_target,y_target)*

When I run this code it gives an error in the last line? Not sure why? Any help is much appreciated!

[Masooma Tahir]

I tried the changes you said but still same error T_target=interp2(x,y,T,x_target,y_target)

Error in ex3 (line 12) T_target=interp2(x,y,T,x_target,y_target)

Answer 1

[Geoff Hayes]

Masooma - you have a period separating the y and the T rather than a comma. Just change your last line to

 T_target=interp2(x,y,T,x_target,y_target)

and try again!

[Masooma Tahir]

I tried the changes you said but still same error T_target=interp2(x,y,T,x_target,y_target) Error in ex3 (line 12) T_target=interp2(x,y,T,x_target,y_target)

[Geoff Hayes]

If I run the code that you have posted and change from the period o the comma, then everything works fine without any errors. I suspect that you haven't posted all of your code or are doing something different without showing it. Please copy and paste the full error message into your question so that we can get an idea as to what the error is.

Answer 2

[Star Strider]

You need to use the griddata function, not interp2:

x=[0 2 4 6 8];
y=[0 2 4 6 8];
T=[100 90 80 70 60; 85 64.49 53.50 48.15 50; 70 48.90 38.43 35.03 40; 55 38.78 30.39 27.07 30; 40 35 30 25 20];
x_target=4;
y_target=3.2;

T_target=griddata(x,y,T,x_target,y_target)

T_target =
    44.4580

figure(1)
surfc(x, y, T);
hold on
stem3(x_target, y_target, T_target, '^r', 'MarkerSize',10, 'MarkerFaceColor','r')
hold off
grid on
view([-130  25])

The interp2 function requires that your data be gridded before using the function. The griddata function creates the grid itself.

Answer 3

[VBBV]

clear 
clc

x=[0 2 4 6 8];
y=[0 2 4 6 8];
T=[100 90 80 70 60; 85 64.49 53.50 48.15 50; 70 48.90 38.43 35.03 40; 55 38.78 30.39 27.07 30; 40 35 30 25 20];
x_target=4;
y_target=3.2;
T_target=interp2(x,y,T,x_target,y_target) % delete the . in interp2 and replace it with , 

T_target = 44.4580

Delete the dot. in the interp2 function