plotting 3d graph

I have a surface, with a function Z plotted as a function of two variables X and Y. The code is:

x = -100:25:100 ;

y = 600:120:1500 ;

[X, Y] = meshgrid(x, y);

Z = 3 *X + 2 ./(Y);

surf(X, Y, Z);

I want to plot the minimum of function Z plotted on the x-axis, for every value of Y.

Something like this (the red line and green marks).

Please help.

I want to plot this:

for y =600, the minimum value of z is -300 at x= -100; plot (x=-100, z=-300)

then for y = 720, the minimum value of z is -300 at x= -100; plot (x=-100, z=-300)

and so on.

Pleas help.

Answer 1

[Amit Bhowmick]

x = -100:25:100 ;
y = 600:120:1500 ;
[X, Y] = meshgrid(x, y);
Z = 3 *X + 2 ./(Y);
surf(X, Y, Z);
fminx=min(abs(Z),[],1)
fminy=min(abs(Z),[],2)
hold;
plot3(zeros(size(y)),y,fminy','ro')

[priya]

I want to plot this:

for y =600, the minimum value of z is -300 at x= -100; plot (x=-100, z=-300)

then for y = 720, the minimum value of z is -300 at x= -100; plot (x=-100, z=-300)

and so on.

Pleas help

[Amit Bhowmick]

[fminx,idx]=min(Z,[],1)
[fminy,idy]=min(Z,[],2)
hold;
plot3(X(:,idy),Y(:,idy),fminy,'ro')

[priya]

Thanks a lot !!