MatLab: how to create a rectangular hole in a hyperbolic paraboloid

Hi all, i'm new in the world of MatLab and for a course at the University i've decided to draw a building with the software. The building is West 57 by BIG in Manhattan. It's a parallelepiped with a big hyperbolic paraboloid above. So now i have found the equation of the hyperbolic paraboloid and also i have drawn the parallelepipid on the base. The problem is that i really don't know how to create the rectangular hole, i know where it has to be, but how can i write it down in MatLab? The code for the hyperbolic paraboloid is:

[s,t]=meshgrid(linspace(0,1,20),linspace(0,1,20));

[X,Y,Z]=meshgrid(0:1:60,0:1:150,0:1:130);

X=(150*s);

Y=(60*t);

Z=((8+(X.*(Y)))-(8870*(s.*t)));

axis tight;

axis equal;

surf(X,Y,Z)

This is the building

and this is the result i've reached in MatLab

The hole is missing xD. Please someone help me :) Thank you for your attention!

Answer 1

[Joseph Cheng]

just create a mask or by change the hole into NaN

[s,t]=meshgrid(linspace(0,1,20),linspace(0,1,20));
[X,Y,Z]=meshgrid(0:1:60,0:1:150,0:1:130);
X=(150*s);
Y=(60*t);
Z=((8+(X.*(Y)))-(8870*(s.*t)));
axis tight;
axis equal;
figure(1),subplot(1,3,1),surf(X,Y,Z)
%generate mask
x = X>=25 & X<=125;
y = Y>=20 & Y<=40;
hole = double(~(x&y));
hole(hole==0)=nan;
subplot(1,3,2),surf(X,Y,Z.*hole)
%or do it all together
Z(X>=25 & X<=125 & Y>=20 & Y<=40)=nan;
subplot(1,3,3),surf(X,Y,Z)

[Image Analyst]

Marco's "Answer" moved here since it's not an answer:

Ohhh thank you very much :) i've got a last question, now ho can i close the hole with 4 surfaces in that exact space? For the biggest surface for example i have tried this code:

[u,v]=meshgrid(linspace(25,125,20),linspace(0,130,20));
w=meshgrid(linspace(40,40,20));
x=u;
y=w;
z=(8+((u.*v)-(16120*(s.*t))));
surf(x,y,z)

but it doesn't work and i don't understand why :(

thank you for the attention :)