xyFrom2PointLine: Extraction of values of a line

In ecor/horizons: How to get horizon profiles from some points with an elevation raster map.

Extraction of values of a line

Description

This function extract the values or the xy coordinate of a line passing through two points.

Usage

xyFrom2PointLine(
  r = NULL,
  points = data.frame(x = c(0, 1), y = c(0, 1)),
  step = NULL,
  radius = NA,
  angle = NA,
  units_angle = c("deg", "rad"),
  fun = NULL,
  ...
)

Arguments

r	a Raster* object
points	data frame containing x and y coordinaates from start and end point
step	step used for the extraction of the segment points
radius	length of the segment from the start point (optional)
angle	angle direction of the segment from the start point (optional). It is counterclockwise from East.
units_angle	string measurement unit angle. It is c("deg","rad")[1], i.e. deg is the default value.
fun	optional aggregation function. Default is NULL. If it not NULL the functions return a vector containing an atomic aggregate value for each raster layer.
...	further arguments for fun

Examples

xy_A <- xyFrom2PointLine(points=data.frame(x=c(0,1),y=c(0,1)),step=0.1)


dem <- raster(system.file("dem/dem_rendena.asc",package="horizons"))

xP <- (xmax(dem)*0.4+xmin(dem)*0.6)
yP <- (ymax(dem)*0.4+ymin(dem)*0.6)

xy_B <- xyFrom2PointLine(r=dem,points=data.frame(x=xP,y=yP),radius=10000,angle=35,units_angle="deg")

max_xy_B <- xyFrom2PointLine(r=dem,points=data.frame(x=xP,y=yP),radius=10000,angle=35,units_angle="deg",fun=max,na.rm=TRUE)
min_xy_B <- xyFrom2PointLine(r=dem,points=data.frame(x=xP,y=yP),radius=10000,angle=35,units_angle="deg",fun=min,na.rm=TRUE)


median_xy_B <- xyFrom2PointLine(r=dem,points=data.frame(x=xP,y=yP),radius=10000,angle=35,units_angle="deg",fun=median,na.rm=TRUE)
median_xy_BA <-  xyFrom2PointLine(r=brick(dem,dem+1),points=data.frame(x=xP,y=yP),radius=10000,angle=35,units_angle="deg",fun=median,na.rm=TRUE)

ecor/horizons documentation built on Jan. 4, 2024, 6:25 p.m.