# Documentation

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# Volume Visualization

Representing gridded volume data as iso, slice, and stream plots

## Functions

 `contourslice` Draw contours in volume slice planes `flow` Simple function of three variables `isocaps` Compute isosurface end-cap geometry `isocolors` Calculate isosurface and patch colors `isonormals` Compute normals of isosurface vertices `isosurface` Extract isosurface data from volume data `reducepatch` Reduce number of patch faces `reducevolume` Reduce number of elements in volume data set `shrinkfaces` Reduce size of patch faces `slice` Volumetric slice plot `smooth3` Smooth 3-D data `subvolume` Extract subset of volume data set `volumebounds` Coordinate and color limits for volume data
 `coneplot` Plot velocity vectors as cones in 3-D vector field `curl` Compute curl and angular velocity of vector field `divergence` Compute divergence of vector field `interpstreamspeed` Interpolate stream-line vertices from flow speed `stream2` Compute 2-D streamline data `stream3` Compute 3-D streamline data `streamline` Plot streamlines from 2-D or 3-D vector data `streamparticles` Plot stream particles `streamribbon` 3-D stream ribbon plot from vector volume data `streamslice` Plot streamlines in slice planes `streamtube` Create 3-D stream tube plot

## Examples and How To

Exploring Volumes with Slice Planes

A slice plane is a surface that takes on coloring based on the values of the volume data in the region where the slice is positioned.

Connecting Equal Values with Isosurfaces

Isosurfaces are constructed by creating a surface within the volume that has the same value at each vertex. Isosurface plots are similar to contour plots in that they both indicate where values are equal.

Isocaps are planes that are fitted to the limits of an isosurface to provide a visual context for the isosurface.

Stream Line Plots of Vector Data

This example shows how to use stream lines, slice planes, and contour lines in one graph.

Displaying Curl with Stream Ribbons

Stream ribbons illustrate direction of flow, similar to stream lines, but can also show rotation about the flow axis by twisting the ribbon-shaped flow line.

Displaying Divergence with Stream Tubes

Stream tubes are similar to stream lines, except the tubes have width, providing another dimension that you can use to represent information.

Creating Stream Particle Animations

A stream particle animation is useful for visualizing the flow direction and speed of a vector field. The particles trace the flow along a particular stream line.

Vector Field Displayed with Cone Plots

This example shows how to use cone plots, isosurfaces, lighting, and camera placement to visualize a vector field.

Gridded Data Interpolation

Interpolation of uniformly sampled data in 2-D, 3-D, N-D

## Concepts

Overview of Volume Visualization

Volume visualization is the creation of graphical representations of data sets that are defined on three-dimensional grids.

Techniques for Visualizing Scalar Volume Data

There are several techniques available for visualizing scalar volume data, such as MRI slices.

Visualizing Vector Volume Data

There are several techniques that are useful for visualizing vector data, such as stream lines, stream particles, stream ribbons, stream tubes, and cone plots.