contour3-With 3 dimensions input arguments

Hello. I have the following: Α:24X24X24, B:24X24X24 and C:24X24X24

I want to make the contour3 plot

contour3(A,B,C)

but it shows me the following error: "Input arguments must have at most 2 dimensions". Is there a way to make a contour3 plot with three dimensions?

Answer 1

[John D'Errico]

In order for a 3-d contour plot to make sense, you need to have some function, W(X,Y,Z), thuis a level surface, where you look for constant values of W as 3-d surfaces.

If all you have are A, B, and C, then a 3-d contour plot makes little sense.

If you actually have a 4th variable, you can use isosurface.

help isosurface

 ISOSURFACE  Isosurface extractor.
    FV = ISOSURFACE(X,Y,Z,V,ISOVALUE) computes isosurface geometry for
    data V at isosurface value ISOVALUE. Arrays (X,Y,Z) specify the points
    at which the data V is given. The struct FV contains the faces and
    vertices of the isosurface and can be passed directly to the PATCH
    command.
    
    FV = ISOSURFACE(V,ISOVALUE) assumes [X Y Z] = meshgrid(1:N, 1:M, 1:P) 
         where [M,N,P]=SIZE(V). 
    
    FV = ISOSURFACE(X,Y,Z,V) or FV = ISOSURFACE(V) selects an
    isosurface value automatically using the histogram of the
    data. 
    
    FVC = ISOSURFACE(..., COLORS) interpolates the array COLORS onto
    the scalar field and returns the interpolated values in
    facevertexcdata. The size of the COLORS array must be the same
    as V. 
    
    FV = ISOSURFACE(..., 'noshare') does not attempt to create
    shared vertices. This is faster, but produces a larger set of
    vertices.  
    
    FV = ISOSURFACE(..., 'verbose') prints progress messages to the
         command window as the computation progresses. 
    
    [F, V] = ISOSURFACE(...) or  [F, V, C] = ISOSURFACE(...)
    returns the faces and vertices (and facevertexcdata) in
    separate arrays instead of a struct. 
    
    ISOSURFACE(...) With no output arguments, a patch is created
    into the current axes with the computed faces and vertices. 
    If no current axes exists, a new axes will be created with 
    a 3-D view.
    
    Example 1:
       [x y z v] = flow;
       p = patch(isosurface(x, y, z, v, -3));
       isonormals(x,y,z,v, p)
       p.FaceColor = 'red';
       p.EdgeColor = 'none';
       daspect([1 1 1])
       view(3)
       camlight; lighting phong
 
    Example 2:
       [x y z v] = flow;
       q = z./x.*y.^3;
       p = patch(isosurface(x, y, z, q, -.08, v));
       isonormals(x,y,z,q, p)
       p.FaceColor = 'interp';
       p.EdgeColor = 'none';
       daspect([1 1 1]); axis tight; 
       colormap(prism(28))
       camup([1 0 0 ]); campos([25 -55 5]) 
       camlight; lighting phong
        
 
    See also ISONORMALS, ISOCAPS, SMOOTH3, SUBVOLUME, REDUCEVOLUME,
             REDUCEPATCH, SHRINKFACES.

    Documentation for isosurface
       doc isosurface

I'm not sure what you intend to see from contour3 given what you have.

Answer 2

[Bjorn Gustavsson]

Maybe you get what you need with the slice function, or perhaps isosurface. From my naive understanding we can draw iso-contours on a 2-D surface - and the extension of such iso-contours in 3-D becomes iso-surfaces. If you want one set of contours on each level in the z-direction you might get use of the attached function.

HTH