R: Writes a list of soil profiles to KML

kml_layer.SoilProfileCollection {plotKML}

R Documentation

Writes a list of soil profiles to KML

Description

Writes object of type "SoilProfileCollection" (a number of soil profiles with site and horizon data) to KML. Several attributes such as horizontal and vertical exaggeration can be passed via arguments.

Usage

kml_layer.SoilProfileCollection(obj, 
     var.name, var.min = 0, var.scale, 
     site_names = profile_id(obj), 
     method = c("soil_block", "depth_function")[1], 
     block.size = 100, 
     color.name, z.scale = 1, x.min, max.depth = 300,
     plot.points = TRUE, 
     LabelScale = get("LabelScale", envir = plotKML.opts) * 0.7,
     IconColor = "#ff0000ff", 
     shape = paste(get("home_url", envir = plotKML.opts), 
         "circlesquare.png", sep = ""), 
     outline = TRUE, visibility = TRUE, extrude = TRUE, tessellate = TRUE, 
     altitudeMode = "relativeToGround", camera.distance = 0.01, 
     tilt = 90, heading = 0, roll = 0, 
     metadata = NULL, html.table = NULL, plot.scalebar = TRUE,
     scalebar = paste(get("home_url", envir = plotKML.opts), 
         "soilprofile_scalebar.png", sep = ""), 
     ... )

Arguments

`obj`	object of class `"SoilProfileCollection"` (package aqp)
`var.name`	target column name in the `horizons` slot
`var.min`	smallest value
`var.scale`	exaggeration in vertical dimension
`site_names`	site names as listed in the site table
`method`	visualization type (soil block or depth-function)
`block.size`	(optional) size of the block of land
`color.name`	(optional) column name carrying the color information for each horizon
`z.scale`	exaggeration in horizontal direction
`x.min`	offset in longitude direction (in decimal degrees)
`max.depth`	maximum height/depht of a profile in cm
`plot.points`	logical; specifies whether to plot horizon centres with attribute values
`LabelScale`	numeric; specifies size of the labels for each horizon
`IconColor`	colors for the labels for each horizon
`shape`	default icon for Google placemarks
`outline`	logical; specifies whether to draw outline for the soil-depth functions (or simply a line)
`visibility`	logical; specifies whether to make the layer visible
`extrude`	logical; specifies whether to extrude horizon centers
`tessellate`	logical; specifies whether to tessellate polygons
`altitudeMode`	by default `relativeToGround`
`camera.distance`	distance from a profile in arc degrees
`tilt`	angle between the direction of the LookAt position and the normal to the surface of the earth
`heading`	orientation towards north
`roll`	rotation about the y axis
`metadata`	(optional) spatial metadata for the input object
`html.table`	(optional) tabular content (attributes) for each horizon
`plot.scalebar`	logical; specifies whether to plot a scale bar next to the profile plot
`scalebar`	default icon for the scale bar
`...`	additional style arguments

Details

Horizon depths are typically expressed in cm, hence the default exaggeration factor (z.scale) is 10. It is highly recommended to turn off the terrain layer in Google Earth, otherwise Google Earth will deform the plots in areas of high relief.

Note

The spatial exaggeration needs to be used because often the detail in the background imagery in Google Earth is limited to a spatial accuracy of 2–20 m, hence there is no point of zooming into objects of size of few meters. These exaggeration factors were selected empirically and will need to be adjusted as the detail in the background imagery increases.

Author(s)

Tomislav Hengl, Dylan Beaudette and Pierre Roudier

References

Algorithms for Quantitative Pedology (https://CRAN.r-project.org/package=aqp)

Examples

## Not run: ## install.packages("aqp", repos="http://R-Forge.R-project.org")
library(aqp)
library(fossil)
library(plyr)
data(ca630)
## Promote to SoilProfileCollection
ca <- join(ca630$lab, ca630$site, type='inner')
depths(ca) <- pedon_key ~ hzn_top + hzn_bot
## extract site data
site(ca) <- ~ mlra + ssa + lon + lat + cntrl_depth_to_top + cntrl_depth_to_bot + sampled_taxon_name
# generate SpatialPoints
library(sp)
coordinates(ca) <- ~ lon + lat
## assign CRS data
proj4string(ca) <- "+proj=longlat +datum=NAD83"
## plot changes in base saturation by sum of cations method (pH 8.2):
kml(ca, method = "depth_function", file.name = "ca_bs_8_2.kml", 
  var.name="bs_8.2", balloon = TRUE)
## plot changes in cation exchange capacity by sum of cations method (pH 8.2):
kml(ca, file.name = "ca_CEC8_2.kml", var.name="CEC8.2", IconColor = "#ff009000")
## plot soil profile as 'block':
kml(ca, file.name = "ca_CEC8_2_block.kml", var.name="CEC8.2", balloon = TRUE)

## End(Not run)

[Package plotKML version 0.5-9 Index]