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Topic: intersection of a surface with a plane
Replies: 4   Last Post: Jan 17, 2013 8:19 PM

 Messages: [ Previous | Next ]
 Murthy Posts: 12 From: Tokyo Registered: 1/4/13
Re: intersection of a surface with a plane
Posted: Jan 16, 2013 6:25 AM

Thank you very much for your reply.

I tried plotting. I got the plots. But I don't how to spot the location(co-ordinates) of the intersection.

syms a b
lhs='2*cos(a)*cosh(b)-(b/a-a/b)*sin(a)*sinh(b)-2';
rhs='0';

[a]=solve(lhs,a,b);

figure
ezsurf(lhs,[-5,5,-5,5])
hold on
ezsurf(rhs,[-5,5,-5,5])

-----.
My main aim was to find the roots of the equation. So, I plotted the equations, from which I can find the roots.

zdiff = lhs - rhs;
C = contours(lhs, rhs, zdiff, [0 0]);
% Extract the x- and y-locations from the contour matrix C.
aL = C(1, 2:end);
bL = C(2, 2:end);

% Interpolate on the first surface to find z-locations for the intersection
% line.
zL = interp2(a, b, lhs, aL, bL);

% Visualize the line.
line(aL, bL, zL, 'Color', 'k', 'LineWidth', 3);

Since, I could not able to spot the value of 'a' and 'b', i was unable to find the roots of the eqn or the intersection of the curves.
Problem with this : [a]=solve(lhs,a,b); was unable to find the explicit solution.

Thank you very much,
Murthy

Date Subject Author
1/16/13 Murthy
1/16/13 Torsten Hennig
1/16/13 Murthy
1/16/13 Torsten Hennig
1/17/13 Murthy