MATLAB Function Reference

slice

Volumetric slice plot

Syntax

slice(V,sx,sy,sz)
slice(X,Y,Z,V,sx,sy,sz)
slice(V,XI,YI,ZI)
slice(X,Y,Z,V,XI,YI,ZI)
slice(...,'method')
h = slice(...)

Description

slice displays orthogonal slice planes through volumetric data.

slice(V,sx,sy,sz) draws slices along the x, y, z directions in the volume V at the points in the vectors sx, sy, and sz. V is an m-by-n-by-p volume array containing data values at the default location X = 1:n, Y = 1:m, Z = 1:p. Each element in the vectors sx, sy, and sz defines a slice plane in the x-, y-, or z-axis direction.

slice(X,Y,Z,V,sx,sy,sz) draws slices of the volume V. X, Y, and Z are three-dimensional arrays specifying the coordinates for V. X, Y, and Z must be monotonic and orthogonally spaced (as if produced by the function meshgrid). The color at each point is determined by 3-D interpolation into the volume V.

slice(V,XI,YI,ZI) draws data in the volume V for the slices defined by XI, YI, and ZI. XI, YI, and ZI are matrices that define a surface, and the volume is evaluated at the surface points. XI, YI, and ZI must all be the same size.

slice(X,Y,Z,V,XI,YI,ZI) draws slices through the volume V along the surface defined by the arrays XI, YI, ZI.

slice(...,'method') specifies the interpolation method. 'method' is 'linear', 'cubic', or 'nearest'.

• linear specifies trilinear interpolation (the default).
• cubic specifies tricubic interpolation.
• nearest specifies nearest neighbor interpolation.

h = slice(...) returns a vector of handles to surface graphics objects.

Remarks

The color drawn at each point is determined by interpolation into the volume V.

Examples

Visualize the function

over the range -2 x 2, -2 y 2, - 2 z 2:

[x,y,z] = meshgrid(-2:.2:2,-2:.25:2,-2:.16:2);
v = x.*exp(-x.^2-y.^2-z.^2);
xslice = [-1.2,.8,2]; yslice = 2; zslice = [-2,0];
slice(x,y,z,v,xslice,yslice,zslice)
colormap hsv


 

Slicing At Arbitrary Angles

You can also create slices that are oriented in arbitrary planes. To do this,

• Create a slice surface in the domain of the volume (surf, linspace).
• Orient this surface with respect the the axes (rotate).
• Get the XData, YData, and ZData of the surface (get).
• Use this data to draw the slice plane within the volume.

For example, these statements slice the volume in the first example with a rotated plane. Placing these commands within a for loop "passes" the plane through the volume along the z-axis.

for i = -2:.5:2
    hsp = surf(linspace(-2,2,20),linspace(-2,2,20),zeros(20)+i);
    rotate(hsp,[1,-1,1],30)
    xd = get(hsp,'XData');
    yd = get(hsp,'YData');
    zd = get(hsp,'ZData');
    delete(hsp)
    slice(x,y,z,v,[-2,2],2,-2) % Draw some volume boundaries
    hold on
    slice(x,y,z,v,xd,yd,zd)
    hold off
    axis tight
    view(-5,10)
    drawnow
end

The following picture illustrates three positions of the same slice surface as it passes through the volume.

Slicing with a Nonplanar Surface

You can slice the volume with any surface. This example probes the volume created in the previous example by passing a spherical slice surface through the volume.

[xsp,ysp,zsp] = sphere;
slice(x,y,z,v,[-2,2],2,-2)  % Draw some volume boundaries

for i = -3:.2:3
    hsp = surface(xsp+i,ysp,zsp);
    rotate(hsp,[1 0 0],90)
    xd = get(hsp,'XData');
    yd = get(hsp,'YData');
    zd = get(hsp,'ZData');
    delete(hsp)
    hold on
    hslicer = slice(x,y,z,v,xd,yd,zd);
    axis tight 
    xlim([-3,3])
    view(-10,35)
    drawnow
    delete(hslicer)
    hold off
end

The following picture illustrates three positions of the spherical slice surface as it passes through the volume.

See Also

interp3, meshgrid

size (serial)

smooth3