soil.texture.uk {plotrix}R Documentation

Soil texture triangle plot using UK conventions

Description

Display a UK style soil texture triangle with optional grid, labels and soil texture points.

Usage

 soil.texture.uk(soiltexture = NULL, main = "",at = seq(0.1, 0.9, by = 0.1),
  axis.labels = c("percent sand", "percent silt", "percent clay"),
  tick.labels = list(l = seq(10, 90, by = 10), r = seq(10, 90, by = 10),
  b = seq(10, 90, by = 10)), show.names = TRUE,
  show.lines = TRUE, col.names = "gray", bg.names = par("bg"),
  show.grid = FALSE, col.axis = "black", col.lines = "gray",
  col.grid = "gray", lty.grid = 3, show.legend = FALSE, label.points = FALSE,
  point.labels = NULL, col.symbols = "black", pch = par("pch"),
  h1 = NA, h3 = NA, t1 = NA, t3 = NA, lwduk = 2, xpos = NA, ypos = NA,
  snames = NA, cexuk = 1.1, ...)

Arguments

soiltexture Matrix of soil textures where each row is a soil sample and three columns containing the percentages of the components sand, silt and clay in the range 0 to 100.
main The title of the soil texture plot. Defaults to nothing.
at Positions on the three axes where ticks will be drawn.
axis.labels Labels for the axes.
tick.labels The tick labels for the three axes.
show.names Logical - whether to show the names of different soil types within the soil triangle.
show.lines Logical - whether to show the boundaries of the different soil types within the soil triangle.
col.names Color of the soil names. Defaults to gray.
bg.names Color to use when drawing a blank patch for the names of soil types.
show.grid Logical - whether to show grid lines at each 10 level of each soil component.
col.axis Color of the triangular axes, ticks and labels.
col.lines Color of the boundary lines. Defaults to gray.
col.grid Color of the grid lines. Defaults to gray.
lty.grid Type of line for the grid. Defaults to dashed.
show.legend Logical - whether to display a legend.
label.points Logical - whether to call thigmophobe.labels to label the points.
point.labels Optional labels for the points or legend.
col.symbols Color of the symbols representing each value.
pch Symbols to use in plotting values.
h1,h3,t1,t3 Points used in drawing boundaries for soil types.
lwduk Line width for the boundaries
xpos,ypos Positions for the soil type labels.
snames Soil type labels.
cexuk Character expansion for the soil type labels.
... Additional arguments passed to triax.points and then points.

Details

soil.texture.uk displays a triangular plot area on which soil textures defined as proportions of sand, silt and clay can be plotted. It is similar to the soil.texture function but uses the UK display conventions.

Value

If soiltexture was included, a list of the x,y positions of the soil types plotted. If not, nil.

Author(s)

Julian Stander

See Also

triax.plot

Examples

 soils.sw.percent<-data.frame(
  Sand=c(67,67,66,67,36,25,24,59,27,9,8,8,20,
  45,50,56,34,29,39,41,94,98,97,93,96,99),
  Silt=c(17,16,9,8,39,48,54,27,46,70,68,68,66,
  34,30,24,48,53,46,48,2,2,2,4,1,1),
  Clay=c(16,17,25,25,25,27,22,14,27,21,24,24,
  14,21,20,20,18,18,15,11,4,0,1,3,3,0))
 soils.sw.cols <- c(1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3,
  3, 3, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6)
 soils.sw.names <- c("Ardington","Astrop","Atrim",
  "Banbury","Beacon","Beckfoot")
 soil.texture.uk(soils.sw.percent,
  main = "Ternary Diagram for Some Soils from South West England",
  col.lines = "black", col.names = "black", show.grid = TRUE,
  col.grid = "blue", lty.grid = 2,  pch = 16, cex = 1.0,
  col.symbols = soils.sw.cols, h1 = NA, h3 = NA, t1 = NA,
  t3 = NA , lwduk = 2, xpos = NA, ypos = NA,
  snames = NA, cexuk = 1.1)
 legend("topleft", legend = soils.sw.names, col = 1:max(soils.sw.cols),
  pch = 16, cex = 1.1, title = "Location", bty = "n")

[Package plotrix version 2.5-5 Index]