plot 3D fun in x, y and z

i want to draw a function f varied in x, y and z such that f = xyz using matlab 2014a

Answer 1

[John BG]

Hi hend

since your function takes in all 3 coordinates, the only way to 'see' or plot the function is slicing the volume comprised by the domain used.

For such purpose the command slice comes really handy, have a look:

N=10
range=[-N:1:N]
[x,y,z] = meshgrid(range,range,range);
v = x.*y.*z;
figure
colormap hsv
for k = range
   hsp = surf(linspace(-N,N,numel(range)),linspace(-N,N,numel(range)),  zeros(numel(range)) + k);
   rotate(hsp,[2,-2,2],15)
   xd = hsp.XData;yd = hsp.YData;zd = hsp.ZData;
   delete(hsp)
   slice(x,y,z,v,[-N,N],2*N,-2*N) %  static volume boundaries
   hold on
   h1=slice(x,y,z,v,xd,yd,zd)  % this is the slicing plane
   hold off
   view(-5,10)
   axis([-10 10 -10 10 -10 10])
   drawnow
   colorbar
end

note the handle h1 to pull the values on the slice plane, that may be useful to extract the slicing plane points with

Xslice=h1.XData 
Yslice=h1.YData 
Zslice=h1.ZData

the colour bar is also useful to visualise the actual value of the function.

if you find these lines useful would you please be so kind consider marking my answer as Accepted Answer?

To any other reader, if you find this answer of any help would you please click on the thumbs-up vote link,

thanks in advance for time and attention

John BG

<mailto:[e-mail] [e-mail]>

Answer 2

[KSSV]

N = 10 ;
x = linspace(0,1,N) ;
y = linspace(0,1,N) ;
z = linspace(0,1,N) ;

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

f = X.*Y.*Z ;

figure(1)
hold on
for i = 1:N
    surf(X(:,:,i),Y(:,:,i),Z(:,:,i),f(:,:,i))
end

[hend]

thanks for help, but that is not a shape for the desired fn, just levels of coloured blocks as image fn not as a shape

[KSSV]

You check the ranges of x, y, z for the given function that's the shape. What you expect? Any image available? Attach it.

[KSSV]

N = 10 ;
x = linspace(0,1,N) ;
y = linspace(0,1,N) ;
z = linspace(0,1,N) ;
[X,Y,Z] = meshgrid(x,y,z) ;

F = X.*Y.*Z ;

isosurface(X,Y,Z,F,0)