3D surface plotting. Error (z must be a matrix)

x_length=50;
for y_length=0:200;
z_length=y_length;
%[z,y]=meshgrid(z_length,y_length);
%i=0:200;
Hyp1=sqrt((x_length.^2)+(y_length.^2));
Hyp2=sqrt((Hyp1.^2)+(z_length.^2));
ctheta_i=y_length/Hyp2;
Lang_walldb=20*(1-ctheta_i).^2;
surf(Lang_walldb)
grid on
xlabel('y length');
ylabel('z length ');
zlabel('angular loss')
hold on
set(gca,'View',[-29,-22]);
end

[madhan ravi]

you never seem to use z & y after meshgrid() call , re-examine why you used it in the first place

[Walter Roberson]

Nothing in your calculation is a vector, let alone a matrix. Your Lang_walldb is always going to be a scalar at the point you do the surf()

Answer 1

[KSSV]

x_length=0:50;
y_length=0:200 ;
[x_length,y_length] = meshgrid(x_length,y_length);

Hyp1=sqrt((x_length.^2)+(y_length.^2));
Hyp2=sqrt((Hyp1.^2)+(y_length.^2));
ctheta_i=y_length./Hyp2;  % edited as suggested my Madhan Ravi
Lang_walldb=20*(1-ctheta_i).^2;


surf(Lang_walldb)
shading interp 
grid on
xlabel('y length');
ylabel('z length ');
zlabel('angular loss')
hold on
set(gca,'View',[-29,-22]);

[madhan ravi]

ctheta_i=y_length./Hyp2; % missed a dot in front of /

[KSSV]

Yes...edited..