# xyFrom2PointLine: Extraction of values of a line In ecor/horizons: How to get horizon profiles from some points with an elevation raster map.

## Description

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

## Usage

 ```1 2 3``` ```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

 `x` a Raster* object `points` data frame containing x and y coordinaates from start and end point `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. `step` step used for the extraction of the segment points `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

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16``` ```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,points=data.frame(x=xP,y=yP),radius=10000,angle=35,units_angle="deg") max_xy_B <- xyFrom2PointLine(r=dem,points,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,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,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,points=data.frame(x=xP,y=yP),radius=10000,angle=35,units_angle="deg",fun=median,na.rm=TRUE) ```

ecor/horizons documentation built on May 13, 2017, 1:04 p.m.