Octave has the functions triplot
, trimesh
, and trisurf
to plot the Delaunay triangulation of a 2-dimensional set of points.
tetramesh
will plot the triangulation of a 3-dimensional set of points.
Plot a 2-D triangular mesh.
tri is typically the output of a Delaunay triangulation over the grid of x, y. Every row of tri represents one triangle and contains three indices into [x, y] which are the vertices of the triangles in the x-y plane.
The linestyle to use for the plot can be defined with the argument linespec of the same format as the
plot
command.The optional return value h is a graphics handle to the created patch object.
Plot a 3-D triangular wireframe mesh.
In contrast to
mesh
, which plots a mesh using rectangles,trimesh
plots the mesh using triangles.tri is typically the output of a Delaunay triangulation over the grid of x, y. Every row of tri represents one triangle and contains three indices into [x, y] which are the vertices of the triangles in the x-y plane. z determines the height above the plane of each vertex. If no z input is given then the triangles are plotted as a 2-D figure.
The color of the trimesh is computed by linearly scaling the z values to fit the range of the current colormap. Use
caxis
and/or change the colormap to control the appearance.Optionally, the color of the mesh can be specified independently of z by supplying a color matrix, c. If z has N elements, then c should be an Nx1 vector for colormap data or an Nx3 matrix for RGB data.
Any property/value pairs are passed directly to the underlying patch object.
The optional return value h is a graphics handle to the created patch object.
See also: mesh, tetramesh, triplot, trisurf, delaunay, patch, hidden.
Plot a 3-D triangular surface.
In contrast to
surf
, which plots a surface mesh using rectangles,trisurf
plots the mesh using triangles.tri is typically the output of a Delaunay triangulation over the grid of x, y. Every row of tri represents one triangle and contains three indices into [x, y] which are the vertices of the triangles in the x-y plane. z determines the height above the plane of each vertex.
The color of the trimesh is computed by linearly scaling the z values to fit the range of the current colormap. Use
caxis
and/or change the colormap to control the appearance.Optionally, the color of the mesh can be specified independently of z by supplying a color matrix, c. If z has N elements, then c should be an Nx1 vector for colormap data or an Nx3 matrix for RGB data.
Any property/value pairs are passed directly to the underlying patch object.
The optional return value h is a graphics handle to the created patch object.
Display the tetrahedrons defined in the m-by-4 matrix T as 3-D patches.
T is typically the output of a Delaunay triangulation of a 3-D set of points. Every row of T contains four indices into the n-by-3 matrix X of the vertices of a tetrahedron. Every row in X represents one point in 3-D space.
The vector C specifies the color of each tetrahedron as an index into the current colormap. The default value is 1:m where m is the number of tetrahedrons; the indices are scaled to map to the full range of the colormap. If there are more tetrahedrons than colors in the colormap then the values in C are cyclically repeated.
Calling
tetramesh (..., "property", "value", ...)
passes all property/value pairs directly to the patch function as additional arguments.The optional return value h is a vector of patch handles where each handle represents one tetrahedron in the order given by T. A typical use case for h is to turn the respective patch
"visible"
property"on"
or"off"
.Type
demo tetramesh
to see examples on usingtetramesh
.
The difference between triplot
, and trimesh
or triplot
,
is that the former only plots the 2-dimensional triangulation itself, whereas
the second two plot the value of a function f (
x,
y)
. An
example of the use of the triplot
function is
rand ("state", 2) x = rand (20, 1); y = rand (20, 1); tri = delaunay (x, y); triplot (tri, x, y);
which plots the Delaunay triangulation of a set of random points in 2-dimensions. The output of the above can be seen in fig:triplot.