stream2 (MATLAB Function Reference)

Compute 2-D stream line data

Syntax

XY = stream2(x,y,u,v,startx,starty)
XY = stream2(u,v,startx,starty)
XY = stream2(...,options)

Description

XY = stream2(x,y,u,v,startx,starty) computes stream lines from vector data u and v. The arrays x and y define the coordinates for u and 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 section Starting Points for Stream Plots in Visualization Techniques provides more information on defining starting points.

The returned value XY contains a cell array of vertex arrays.

XY = stream2(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).

XY = stream2(...,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]

[stepsize, max_number_vertices]

If you do not specify a value, MATLAB uses the default:

stepsize = 0.1 (one tenth of a cell)
naximum number of vertices = 1000

Use the streamline command to plot the data returned by stream2.

Examples

This example draws 2-D stream lines from data representing air currents over regions of North America.

load wind
[sx,sy] = meshgrid(80,20:10:50);
streamline(stream2(x(:,:,5),y(:,:,5),u(:,:,5),v(:,:,5),sx,sy));

strcmpi stream3