layer.SoilProfileCollection: Writes a list of soil profiles to KML

In Envirometrix/plotKML: Visualization of Spatial and Spatio-Temporal Objects in Google Earth

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)

See Also

kml_layer.SpatialPhotoOverlay, plotKML-method

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)

Envirometrix/plotKML documentation built on June 13, 2022, 11:21 p.m.