Extract data for 3d plated grave
Afficher commentaires plus anciens
Hello everyone!
i just started learing mathlab. i did plot a simple 3d graph of circles by this code ;
clear;
clc;
figure(1)
r=3;
th=0:180/30:360;
Lgt=length(th);
for height=0:4:20;
x=r*cos(th);
y=r*sin(th);
z= height* ones(r,Lgt);
plot3(x,y,z)
hold on
r=r+5;
end
hold off
when i came to extract the ploted graph 3d data i tried different way among them
ch=get(gca,'children')
X=get(ch,'Xdata')
Y=get(ch,'Ydata')
Z=get(ch,'Zdata')
which resulted in many many date, like repeated 20 20 20 many times while it should just gave me on raw of 20s one of 16s...0s
the same with x and y .
how to extract them correctly?
thanks in advance
Réponses (1)
Let's first run your code:
figure(1)
r=3;
th=0:180/30:360;
Lgt=length(th);
for height=0:4:20;
x=r*cos(th);
y=r*sin(th);
z= height* ones(r,Lgt);
plot3(x,y,z)
hold on
r=r+5;
end
hold off
ch=get(gca,'Children')
X=get(ch,'XData')
As you can see, each circle in your plot is a separate line object. The get function will return a cell array with a cell element for each line. Since the x and y don't actually depend on your loop variable (and therefor could be computed outside the loop), you can just select one of them.
The ZData property contains 1 z value for every x and y. Otherwise it wouldn't be possible to plot them. If you're only after a single value, you could either select 1 value at random, or use unique (which will allow you to detect multiple heigths).
Z=get(ch,'ZData');
for n=1:numel(Z)
Z{n}=unique(Z{n});
end
Z
Catégories
En savoir plus sur Programming dans Centre d'aide et File Exchange
le 12 Avr 2022
le 12 Avr 2022
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
