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math::geometry(n) 1.0.2 "Math"
math::geometry - Geometrical computations
TABLE OF
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SYNOPSIS
DESCRIPTION
PROCEDURES
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COPYRIGHT
package require Tcl ?8.3?
package require math::geometry ?1.0.2?
The math::geometry package is a collection of
functions for computations and manipulations on two-dimensional
geometrical objects, such as points, lines and polygons.
The geometrical objects are implemented as plain lists of
coordinates. For instance a line is defined by a list of four
numbers, the x- and y-coordinate of a first point and the x- and
y-coordinates of a second point on the line.
The various types of object are recognised by the number of
coordinate pairs and the context in which they are used: a list of
four elements can be regarded as an infinite line, a finite line
segment but also as a polyline of one segment and a point set of
two points.
Currently the following types of objects are distinguished:
- point - a list of two coordinates representing the x-
and y-coordinates respectively.
- line - a list of four coordinates, interpreted as the
x- and y-coordinates of two distinct points on the line.
- line segment - a list of four coordinates, interpreted
as the x- and y-coordinates of the first and the last points on the
line segment.
- polyline - a list of an even number of coordinates,
interpreted as the x- and y-coordinates of an ordered set of
points.
- polygon - like a polyline, but the implicit assumption
is that the polyline is closed (if the first and last points do not
coincide, the missing segment is automatically added).
- point set - again a list of an even number of
coordinates, but the points are regarded without any ordering.
The package defines the following public procedures:
- ::math::geometry::calculateDistanceToLine P line
- Calculate the distance of point P to the (infinite) line and
return the result
- list P
- List of two numbers, the coordinates of the point
- list line
- List of four numbers, the coordinates of two points on the
line
- ::math::geometry::calculateDistanceToLineSegment P linesegment
- Calculate the distance of point P to the (finite) line segment
and return the result.
- list P
- List of two numbers, the coordinates of the point
- list linesegment
- List of four numbers, the coordinates of the first and last
points of the line segment
- ::math::geometry::calculateDistanceToPolyline P polyline
- Calculate the distance of point P to the polyline and return
the result.
- list P
- List of two numbers, the coordinates of the point
- list polyline
- List of numbers, the coordinates of the vertices of the
polyline
- ::math::geometry::findClosestPointOnLine P line
- Return the point on a line which is closest to a given
point.
- list P
- List of two numbers, the coordinates of the point
- list line
- List of four numbers, the coordinates of two points on the
line
- ::math::geometry::findClosestPointOnLineSegment P linesegment
- Return the point on a line segment which is closest to
a given point.
- list P
- List of two numbers, the coordinates of the point
- list linesegment
- List of four numbers, the first and last points on the line
segment
- ::math::geometry::findClosestPointOnPolyline P polyline
- Return the point on a polyline which is closest to a
given point.
- list P
- List of two numbers, the coordinates of the point
- list polyline
- List of numbers, the vertices of the polyline
- ::math::geometry::lengthOfPolyline polyline
- Return the length of the polyline (note: it not
regarded as a polygon)
- list polyline
- List of numbers, the vertices of the polyline
Other functions: Pro Memorie
angle , distance , line , math , plane geometry , point
Copyright © 2004 by Ideogramic ApS and other parties