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Plot velocity vectors as cones in a 3-D vector field



coneplot(X,Y,Z,U,V,W,Cx,Cy,Cz) plots velocity vectors as cones pointing in the direction of the velocity vector and having a length proportional to the magnitude of the velocity vector.

coneplot(U,V,W,Cx,Cy,Cz) (omitting the X, Y, and Z arguments) assumes [X,Y,Z] = meshgrid(1:n,1:m,1:p) where [m,n,p]= size(U).

coneplot(...,s) MATLAB automatically scales the cones to fit the graph and then stretches them by the scale factor s. If you do not specify a value for s, MATLAB uses a value of 1. Use s = 0 to plot the cones without automatic scaling.

coneplot(...,color) interpolates the array color onto the vector field and then colors the cones according to the interpolated values. The size of the color array must be the same size as the U, V, W arrays. This option works only with cones (i.e., not with the quiver option).

coneplot(...,'quiver') draws arrows instead of cones (see quiver3 for an illustration of a quiver plot).

coneplot(...,'method') specifies the interpolation method to use. method can be linear, cubic, or nearest. linear is the default (see interp3 for a discussion of these interpolation methods).

coneplot(X,Y,Z,U,V,W,'nointerp') does not interpolate the positions of the cones into the volume. The cones are drawn at positions defined by X, Y, Z and are oriented according to U, V, W. Arrays X, Y, Z, U, V, W must all be the same size.

coneplot(axes_handle,...) plots into the axes with handle axes_handle instead of the current axes (gca).

h = coneplot(...) returns the handle to the patch object used to draw the cones. You can use the set command to change the properties of the cones.


coneplot automatically scales the cones to fit the graph, while keeping them in proportion to the respective velocity vectors.

It is usually best to set the data aspect ratio of the axes before calling coneplot. You can set the ratio using the daspect command,


This example plots the velocity vector cones for vector volume data representing the motion of air through a rectangular region of space. The final graph employs a number of enhancements to visualize the data more effectively. These include

1. Load and Inspect Data

The winds data set contains six 3-D arrays: u, v, and w specify the vector components at each of the coordinates specified in x, y, and z. The coordinates define a lattice grid structure where the data is sampled within the volume.

It is useful to establish the range of the data to place the slice planes and to specify where you want the cone plots (min, max).

2. Create the Cone Plot

3. Add the Slice Planes

4. Define the View

5. Add Lighting to the Scene

The light source affects both the slice planes (surfaces) and the cone plots (patches). However, you can set the lighting characteristics of each independently.

See Also

isosurface, patch, reducevolume, smooth3, streamline, stream2, stream3, subvolume

Volume Visualization for related functions

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