# plotting 3d graph

9 views (last 30 days)
priya on 5 Jul 2021
Commented: priya on 5 Jul 2021
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). 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 on 5 Jul 2021
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 on 5 Jul 2021
Thanks a lot !!

R2017a

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