16_other_main_geometric_objects: Other Main Geometric Objects

In vectools: Advanced Vector Toolkit

Description

Geometric objects, resembling a grid, containing quadralaterals.

These can be plotting using either the base or grid graphics systems.

These functions take three matrices.
For regularly-spaced or semi-regularly-spaced grids, it may be easier to use the rectGrid and rectVImage functions, which take two vectors and a matrix.

NOTE:
INTERNAL STRUCTURE OF OBJECTS IS SUBJECT TO CHANGE.
DO NOT USE SLOTS, DIRECTLY.

Usage

Grid (x, y, gv=NULL, ..., glist = list (), vlist=NULL)
VImage (x, y, gv=NULL, ..., tf=FALSE, colm, glist = list () )

as.Grid (v, ..., glist = list(), vlist = NULL)

Arguments

x, y	Numeric matrices of coordinates.
gv	A numeric matrix, giving the "z" value at each "x" and "y" pair. If null, a 2D grid is created. Can also be a scalar value, but this is mainly for testing and demo purposes.
v	Currently, an FGrid object, such as one returned by the cgrid function.
glist	Argument list for plotting functions.
vlist	Same as glist, except that each element is a matrix, corresponding to each quadralateral. The number of rows and columns for each element, should be one less than gv. Note that glist and vlist should contain distinct names.
tf	Logical, transpose and flip colm. By default, x and y have their standard meanings. Setting tf to true, allows raster-style data to be rendered properly.
colm	A character matrix of colors. The number of rows and columns for each element, should be one less than gv.
...	Ignored.

Details

Note that the plot methods for VImage will plots the colors (like a heatmap) if colm is provided.
Otherwise, it will plot a grid of lines.

Value

A Grid or VImage object.

See Also

Points, Line, Polygon

RImage-class

rectGrid, rectVImage
Refer to these functions, for examples.
(These use simple vectors for x and y, rather than matrices).

vectools documentation built on June 7, 2021, 9:08 a.m.