meshing {RGeostats}R Documentation

Perform Meshing

Description

Perform Meshing

Usage

meshing(db=NA, dbaux=NA, triswitch = "Q", gext=NA,
        extendmin=NA, extendmax=NA, cellsize=NA, rotmat=NA,
        mesh=NA, verbose = FALSE,  flag.plot=FALSE, ...)

Arguments

db

First db-class to be taken into account for meshing.

dbaux

Auxilary db-class to be taken into account for meshing.

triswitch

The argument 'triswitch' depends on the type of meshing (i.e triangles, tetrehedra or triangles on the sphere).

For Triangulation, please use the following keywords:

  • p Triangulates a Planar Straight Line Graph.

  • r Refines a previously generated mesh.

  • q Quality mesh generation. A minimum angle may be specified.

  • a Applies a maximum triangle area constraint.

  • u Applies a user-defined triangle constraint.

  • A Applies attributes to identify triangles in certain regions.

  • c Encloses the convex hull with segments.

  • D Conforming Delaunay: all triangles are truly Delaunay.

  • j Jettison unused vertices from output .node file.

  • e Generates an edge list.

  • v Generates a Voronoi diagram.

  • n Generates a list of triangle neighbors.

  • B Suppresses output of boundary information.

  • P Suppresses output of .poly file.

  • N Suppresses output of .node file.

  • E Suppresses output of .ele file.

  • I Suppresses mesh iteration numbers.

  • O Ignores holes in .poly file.

  • X Suppresses use of exact arithmetic.

  • z Numbers all items starting from zero (rather than one).

  • o2 Generates second-order subparametric elements.

  • Y Suppresses boundary segment splitting.

  • S Specifies maximum number of added Steiner points.

  • l Uses vertical cuts only, rather than alternating cuts.

  • s Force segments into mesh by splitting (instead of using CDT).

  • C Check consistency of final mesh.

  • Q Quiet: No terminal output except errors.

  • V Verbose: Detailed information on what I'm doing.

  • h Help: Detailed instructions for Meshing.

For Tetrahedralization, please use the following keywords:

  • p Tetrahedralizes a piecewise linear complex (PLC).

  • Y Preserves the input surface mesh (does not modify it).

  • r Reconstructs a previously generated mesh.

  • q Refines mesh (to improve mesh quality).

  • R Mesh coarsening (to reduce the mesh elements).

  • A Assigns attributes to tetrahedra in different regions.

  • a Applies a maximum tetrahedron volume constraint.

  • m Applies a mesh sizing function.

  • i Inserts a list of additional points.

  • O Specifies the level of mesh optimization.

  • S Specifies maximum number of added points.

  • T Sets a tolerance for coplanar test (default 1e-8).

  • X Suppresses use of exact arithmetic.

  • M No merge of coplanar facets or very close vertices.

  • w Generates weighted Delaunay (regular) triangulation.

  • c Retains the convex hull of the PLC.

  • d Detects self-intersections of facets of the PLC.

  • z Numbers all output items starting from zero.

  • J No jettison of unused vertices from output .node file.

  • B Suppresses output of boundary information.

  • N Suppresses output of .node file.

  • E Suppresses output of .ele file.

  • F Suppresses output of .face and .edge file.

  • I Suppresses mesh iteration numbers.

  • C Checks the consistency of the final mesh.

  • Q Quiet: No terminal output except errors.

  • V Verbose: Detailed information, more terminal output.

  • h Help: A brief instruction for Meshing.

For Triangulation on the Sphere, please use the following keywords (followed by 'xxx') to generate points on the Sphere

  • -nxxx Generate two times 'xxx' points according to Van der Corput algorithm (for example -n1000)

  • -rxxx Regular points in 'xxx' discretization steps of sphere (warning: the number of points grows rapidly ... Use -r4 for example)

gext

The 'dbaux' may be dilated by gext. This argument designates an array, with its dimension equal to the dimension of the space and which contains the extension in each direction.

extendmin

Array containing the minimum values along all space coordinates. This information is compulsory to run the Turbo Meshing. It will be ignored when using the Standard Meshing ('dbin' or 'dbout' defined).

extendmax

Array containing the maximum values along all space coordinates. This information is compulsory to run the Turbo Meshing. It will be ignored when using the Standard Meshing ('dbin' or 'dbout' defined).

cellsize

Array containing the spacing interval along all space coordinates. This information is compulsory to run the Turbo Meshing. It will be ignored when using the Standard Meshing ('dbin' or 'dbout' defined).

rotmat

Array containing the rotation matrix (Dimension: ndim x ndim). This argument is optional. It will be used when running the Turbo Meshing and will be ignored when using the Standard Meshing ('dbin' or 'dbout' defined).

mesh

When provided, this argument provides the already existing meshing, i.e. a mesh-class object.

verbose

Verbose flag

flag.plot

When TRUE, the constraining vertices, holes and segments are represented. The created triangles are also represented.

...

Arguments passed for graphic function such as mesh.plot.

Details

This function allows to define the meshing using ont of the following possibilities:

Note that when several entries are possible, the choice is performed according to the list given above.

Value

The resulting mesh-class object.

Examples

# Load the Data Set from Jonathan Richard Shewchuk web site.
rg.load("Demo.double.hex.db","tri.db")

# Perform the basic triangulation #
res = meshing(db=tri.db,triswitch="Q")

# Perform the triangulation with surface constraint #
res = meshing(db=tri.db,triswitch="Qa0.005")

# Remove file
rm(tri.db, tri.res)
[Package RGeostats version 14.0.10 Index]