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treecm (version 1.2.2)

getCoordinatesAndMoment: Returns the coordinates of centre of mass of branches and logs

Description

Computes the cartesian coordinates of centre of mass of branches and logs along with their $x$, $y$, $z$ moments

The $x$ and $y$ coordinates are computed from the polar coordinates (angle and distance, defined as the length of its projection on ground), measured in the field. The $z$ coordinate is computed by adding the height of branch insertion on the stem (measured in the field) to the height of the branch (calculated through its mean tilt, in case it was measured in the filed). The $x$, $y$, $z$ coordinates are corrected to take into account where the actual centre of mass lies on the branches themselves by multiplying them by branchesCM, a real number from 0.01 (CM at branch base) to 1.00 (CM at branch tip). As a rule of thumb, average live branches, with an average amount of foliage, have CM approx. $2/3$ of their length, ie. branchesCM = 0.66. $x$, $y$, $z$ moments are computed by multiplying the corresponding cartesian coordinates by branch or log mass, e.g. $m_x = F \cdot l_x$, where $F$ is branch or log mass, $l_x$ is the $x$ component of the lever arm (e.g. the $x$ component of the branch or log projection on the ground).

Usage

getCoordinatesAndMoment(azimuth, dBase, dTip, length, tipD, height, tilt, toBePruned, biomass, branchesCM)

Arguments

azimuth
Branch compass heading
dBase
unused argument
dTip
unused argument
length
Branch length
tipD
unused argument
height
Height of branch insertion on the stem or the height of log lower section
tilt
Inclination of the branch or log in degrees
toBePruned
unused argument
biomass
Mass of the branch or log
branchesCM
a real number varying from 0.01 to 1 proportional to the centre of mass position along the branch (0.01 branch base, 1 branch tip)

Value

a vector holding 5 reals:
  • the $x$ coordinate of branch CM
  • the $y$ coordinate of branch CM
  • the $x$ moment of the branch
  • the $y$ moment of the branch
  • the $z$ moment of the branch