TT.polygon.area

Vector of numericals. X coordinates of each vertices of the 
polygon.

pol.x

Vector of numericals. Y coordinates of each vertices of the 
polygon.

pol.y

Determines the area of 1 non-intersecting polygon (in x-y 
coordinates). Used by TT.polygon.centroids(). pol.x[1]:pol.y[1] 
is supposed different from pol.x[n]:pol.y[n] (i.e. the polygon 
is NOT closed). 
After "http://local.wasp.uwa.edu.au/~pbourke/geometry/polyarea/
Calculating The Area And Centroid Of A Polygon. Written by 
Paul Bourke, July 1988".

"The Soil Texture Wizard" is a set of R functions designed
        to produce texture triangles (also called texture plots,
        texture diagrams, texture ternary plots), classify and
        transform soil textures data. These functions virtually allows
        to plot any soil texture triangle / classification into any
        triangle geometry (isosceles, right-angled triangles, etc.).
        This set of function is expected to be useful to people using
        soil textures data from different soil texture classification
        or different particle size systems. Several texture triangles
        are predefined: USDA; FAO (which is also the triangle for the
        soil map of Europe); Aisne (France); GEPPA (France); German
        triangles "Bodenkundliche Kartieranleitung 1994", "SEA 1974"
        and "TGL 1985"; Soil Survey of England and Wales; Australian
        triangle; Belgian triangle; Canadian triangle; ISSS triangle;
        Romanian triangle; Polish triangle.

TT.polygon.area: Determines the area of 1 polygon (in x-y coordinates).

Description

Usage

Arguments

Value