rPAex (version 1.0.1)

borderPoint: Build the Edge Equations the Experimental Plot

Description

With 4 points and their x and y coordinates of a Raster image, the function constructs the equations of the edge of the experimental plot. Its usefulness is to discriminate the unused area and also to study the responses of the spectrum electromagnetic radiation of the external environment of the area under study.

Usage

borderPoint(Q)

Value

models

list regression linear models

Arguments

Q

list, Matrix, data.frame or arrays with coordinates x,y

Author

Felipe de Mendiburu

Details

The four points can be obtained from a plot with locator(4) function. If the input data is a matrix, its size will be 4 rows and 2 columns.

See Also

externalPoint, fixedPoint, fourPoint, imageField, designRaster, movePlot

Examples

# use corn crop information
library(rPAex)
crop <- system.file("external/corn.csv", package="rPAex")
s<-read.csv(crop,header = TRUE)
r <- raster::rasterFromXYZ(s)
raster::image(r,useRaster=FALSE,main="Area outside the experimental plot")
#P<-locator(3)
# simulated area
P<-list(x=c(287705.9, 287711.8, 287712.8),y=c(8664203.15, 8664204.8, 8664193.67))
Q<-fourPoint(P)
models<-borderPoint(Q)
abline(models$m1)
abline(models$m2)
abline(models$m3)
abline(models$m4)
text(Q,cex=2)