## Documentation Center |

Create 3-D stream tube plot

`streamtube(X,Y,Z,U,V,W,startx,starty,startz)streamtube(U,V,W,startx,starty,startz)streamtube(vertices,X,Y,Z,divergence)streamtube(vertices,divergence)streamtube(vertices,width)streamtube(vertices)streamtube(...,[scale n])streamtube(axes_handle,...)h = streamtube(...z)`

`streamtube(X,Y,Z,U,V,W,startx,starty,startz)`
draws stream tubes from vector volume data `U`, `V`, `W`.

The arrays `X`, `Y`, and `Z`,
which define the coordinates for `U`, `V`,
and `W`, must be monotonic, but do not need to be
uniformly spaced. `X`, `Y`, and `Z` must
have the same number of elements, as if produced by `meshgrid`.

`startx`, `starty`, and `startz` define
the starting positions of the streamlines at the center of the tubes.
The section Specifying
Starting Points for Stream Plots provides more information
on defining starting points.

The width of the tubes is proportional to the normalized divergence of the vector field.

`streamtube(U,V,W,startx,starty,startz)`
assumes `X`, `Y`, and `Z` are
determined by the expression

[X,Y,Z] = meshgrid(1:n,1:m,1:p)

where `[m,n,p] = size(U)`.

`streamtube(vertices,X,Y,Z,divergence)`
assumes precomputed streamline vertices and divergence. `vertices` is
a cell array of streamline vertices (as produced by `stream3`). `X`, `Y`, `Z`,
and `divergence` are 3-D arrays.

`streamtube(vertices,divergence)`
assumes `X`, `Y`, and `Z` are
determined by the expression

[X,Y,Z] = meshgrid(1:n,1:m,1:p)

where `[m,n,p] = size(divergence)`.

`streamtube(vertices,width)`
specifies the width of the tubes in the cell array of vectors, `width`.
The size of each corresponding element of `vertices` and `width` must
be equal. `width` can also be a scalar, specifying
a single value for the width of all stream tubes.

`streamtube(vertices)` selects
the width automatically.

`streamtube(...,[scale n])`
scales the width of the tubes by `scale`. The default
is `scale = 1`. When the stream tubes are created,
using start points or divergence, specifying `scale = 0` suppresses
automatic scaling. `n` is the number of points along
the circumference of the tube. The default is `n = 20`.

`streamtube(axes_handle,...)`
plots into the axes object with the handle `axes_handle` instead
of into the current axes object (`gca`).

`h = streamtube(...z)` returns
a vector of handles (one per start point) to `surface` objects
used to draw the stream tubes.

This example uses stream tubes to indicate the flow in the `wind` data
set. Inputs include the coordinates, vector field components, and
starting location for the stream tubes.

figure load wind [sx sy sz] = meshgrid(80,20:10:50,0:5:15); streamtube(x,y,z,u,v,w,sx,sy,sz); % Define viewing and lighting view(3) axis tight shading interp; camlight; lighting gouraud

This example uses precalculated vertex data (`stream3`)
and divergence (`divergence`).

figure load wind [sx sy sz] = meshgrid(80,20:10:50,0:5:15); verts = stream3(x,y,z,u,v,w,sx,sy,sz); div = divergence(x,y,z,u,v,w); streamtube(verts,x,y,z,-div); % Define viewing and lighting view(3) axis tight shading interp camlight; lighting gouraud

`divergence` | `meshgrid` | `stream3` | `stream3` | `streamline` | `streamribbon`

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