borderPoint {rPAex}

Border in the experimental units

Description

Generates the spectral information of the edge of the EUs for analysis of the border effect, it requires the spectral image, the distance of the border and the segmentation of the EUs generated by imageField.

Usage

borderPoint(r,Rbook,distance,plotting=TRUE,...)

Arguments

r

spectral image

Rbook

Object generated by imageField

distance

distance defining the border of the exterior to the experimental plot

plotting

Logic value to display the image of the border effect around the EUs

...

plot parameter to document the image as main, axis, etc

Details

Set the border in terms of distance in units measured in the field

Value

Qborder

Border bounds matrix

border

dataframe spectral border and that is expressed in the image.

Author(s)

Felipe de Mendiburu

See Also

cassava, fourPoint, imageField

Examples

# use cassava crop information
library(rPAex)
data(cassava)
r <- terra::rast(cassava,type="xyz")
# cassava area
# Apply: x11()
terra::image(r,axes=FALSE)
# p <- locator(3) to generate 3 points in the area
p<-list(x=c(287689.4, 287702.8, 287706.2),y=c(8664210, 8664214, 8664179))
# Generate the fourth points of the area
q<-fourPoint(p)
op<-par(mfrow=c(1,3),mar=c(0,0,0,0))
terra::image(r,axes=FALSE)
text(287693.3,8664215,"Image crop",cex=1.5)
r <- terra::rast(cassava,type="xyz")
# cassava area
# Apply: p <- locator(3) to generate 3 points in the area

p<-list(x=c(287689.4, 287702.8, 287706.2),y=c(8664210, 8664214, 8664179))
# Generate the fourth points of the area
q<-fourPoint(p)
op<-par(mfrow=c(1,3),mar=c(0,0,0,0))
terra::image(r,axes=FALSE)
text(287693.3,8664215,"Image crop",cex=1.5)
# The area is divided into 3x2 plots of 11x6 meters per experimental unit
Rbook<-imageField(r,q,3,2,11,6,plotting=TRUE)
out<-borderPoint(r,Rbook,distance=1,axes=FALSE)
text(287693.4, 8664214, "Border",cex=1.5)
# NDVI in border
ndvi<-with(out$Border, (L1-L2)/(L1+L2))
# NDVI > 0.5 more probability of vegetation
plt<-out$Border[ndvi>0.5,1:2]
w<-terra::rast(out$Border)
text(287693.3,8664215,"Border",cex=1,5)
terra::image(w,axes=FALSE)
text(287693.3,8664215,"Vegetation",cex=1.5)
points(plt,cex=0.2,col=colors()[51],pch=20)
par(op)