MATLAB Function Reference

streamline

Draw stream lines from 2-D or 3-D vector data

Syntax

h = streamline(X,Y,Z,U,V,W,startx,starty,startz)
h = streamline(U,V,W,startx,starty,startz)
h = streamline(XYZ)
h = streamline(X,Y,U,V,startx,starty)
h = streamline(U,V,startx,starty)
h = streamline(XY)
h = streamline(...,options)

Description

h = streamline(X,Y,Z,U,V,W,startx,starty,startz) draws stream lines from 3-D 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, 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 output argument h contains a vector of line handles, one handle for each stream line.

h = streamline(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).

h = streamline(XYZ) assumes XYZ is a precomputed cell array of vertex arrays (as produced by stream3).

h = streamline(X,Y,U,V,startx,starty) draws stream lines from 2-D vector data U, V. The arrays X, Y define the coordinates for U, V and must be monotonic and 2-D plaid (such as the data produced by meshgrid). startx and starty define the starting positions of the stream lines. The output argument h contains a vector of line handles, one handle for each stream line.

h = streamline(U,V,startx,starty) assumes the arrays X and Y are defined as [X,Y] = meshgrid(1:N,1:M) where [M,N] = size(U).

h = streamline(XY) assumes XY is a precomputed cell array of vertex arrays (as produced by stream2).

streamline(...,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)
• naximum number of vertices = 1000

Examples

This example draws stream lines from data representing air currents over a region of North America. Loading the wind data set creates the variables x, y, z, u, v, and w in the MATLAB workspace.

The plane of stream lines indicates the flow of air from the west to the east (the x direction) beginning at x = 80 (which is close to the minimum value of the x coordinates). The y and z coordinate starting points are multivalued and approximately span the range of these coordinates. meshgrid generates the starting positions of the stream lines.

load wind
[sx,sy,sz] = meshgrid(80,20:10:50,0:5:15);
h = streamline(x,y,z,u,v,w,sx,sy,sz);
set(h,'Color','red')
view(3)

See Also

stream2, stream3, coneplot, isosurface, smooth3, subvolume, reducevolume

stream3

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