walkThroughFlag_field: To determine a tree-level flag in a walk-through sample in...

In bcgov/FAIBBase: Basic functions for forest mensuration and ecology

To determine a tree-level flag in a walk-through sample in the field

Description

This function determines the walk-through area and assign walk-through flag for a tree

Usage

walkThroughFlag_field(
  bearingBoundary,
  distanceBoundary,
  radiusYSM = 11.28,
  treeList
)

Arguments

bearingBoundary	numeric, The bearing (degree) for a walk-through edge.
distanceBoundary	numeric, The distance (m) between IPC to the walk-through edge.
radiusYSM	numeric, The radius (m) of a fixed area plot, default is 11.28, which is BC's YSM plot radius.
treeList	list, Defines a tree number, bearing and distance of a tree from IPC.

Value

The function returns three objects: 1. a figure shows the plot and boundary and trees with wkthrough codes 2. a lookup table in which a field crew can identify a tree's wkthrough codes based on a tree's bearing. 3. assigned wkthrough codes for the trees provided.

Note

This method is adapted from Ducey 2004 paper. The population boundary is a simple straight line, which is defined by the boundary bearing (bearingBoundary) and boundary distance (distanceBoundary). Purple line (from P1 to P4) is the boundary. P1 to P4 are the four pins. The dark grey area is the walkthrough area, in which all trees should be marked as W. The white area in the circular plot is out of the plot, in which trees should be marked as O. No mark should be made for trees in rest of the plot (light grey area). pin1 (P1 in green) is always the right direction (90 degree on your right) from the distance point (D in red) with your back to the IPC. The bearing of boundary is clock-wise angle from the North to the D-P1. The distance of boundary is between IPC and D.

Author(s)

Yong Luo

Examples

## Not run: 
# for bearing of 45 with distance of 4.5
plot_exam_fld <- walkThroughFlag_field(bearingBoundary = 45,
                              distanceBoundary = 11.30,
                              treeList = list(c(1, 30, 2),
                                              c(5, 120, 6),
                                              c(6, 160, 10),
                                              c(8, 250, 7),
                                              c(9, 110, 9),
                                              c(10, 340, 9),
                                              c(12, 340, 11),
                                              c(13, 320, 13)))

## End(Not run)

bcgov/FAIBBase documentation built on Feb. 12, 2025, 7:28 p.m.