Compute 2-D streamline data

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

XY = stream2(u,v,startx,starty)

XY = stream2(...,options)

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

computes streamlines from vector data `u`

and `v`

.

The arrays `x`

and `y`

, which
define the coordinates for `u`

and `v`

,
must be monotonic, but do not need to be uniformly spaced. `x`

and `y`

must
have the same number of elements, as if produced by `meshgrid`

.

`startx`

and `starty`

define
the starting positions of the streamlines. The section "Specifying Starting
Points for Stream Plots" 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 streamlines. 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 streamline:

[stepsize]

or

[stepsize, max_number_vertices]

If you do not specify a value, MATLAB^{®} software uses the
default:

Step size = 0.1 (one tenth of a cell)

Maximum number of vertices = 10000

Use the `streamline`

command
to plot the data returned by `stream2`

.

This example draws 2-D streamlines 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));

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