MATLAB Function Reference
stream3

Compute 3-D stream line data

Syntax

• ```XYZ = stream3(X,Y,Z,U,V,W,startx,starty,startz)
XYZ = stream3(U,V,W,startx,starty,startz)
```

Description

`XYZ = stream3(X,Y,Z,U,V,W,startx,starty,startz)` computes stream lines from vector data `U`, `V`, `W`. The arrays `X`, `Y`, `Z` define the coordinates for `U`, `V`, `W` and must be monotonic and 3-D plaid (such as the data produced by `meshgrid`). `startx`, `starty`, and `startz` define the starting positions of the stream lines. The section Starting Points for Stream Plots in Visualization Techniques provides more information on defining starting points.

The returned value `XYZ` contains a cell array of vertex arrays.

`XYZ = stream3(U,V,W,startx,starty,startz)` assumes the arrays `X`, `Y`, and `Z` are defined as `[X,Y,Z] = meshgrid(1:N,1:M,1:P)` where `[M,N,P] = size(U)`.

`XYZ = stream3(...,options)` specifies the options used when creating the stream lines. Define `options` as a one or two element vector containing the step size or the step size and the maximum number of vertices in a stream line:

• ```[stepsize]
```

or

• ```[stepsize, max_number_vertices]
```

If you do not specify values, MATLAB uses the default:

• stepsize = 0.1 (one tenth of a cell)
• maximum number of vertices = 10000

Use the `streamline` command to plot the data returned by `stream3`.

Examples

This example draws 3-D stream lines from data representing air currents over regions of North America.

• ```load wind
[sx sy sz] = meshgrid(80,20:10:50,0:5:15);
streamline(stream3(x,y,z,u,v,w,sx,sy,sz))
view(3)
```

`coneplot`, `stream2`, `streamline`