USDA Textural Soil Classification

Included in the next version (1.0.3.1) of ggtern, will be a new data set, taken from the USDA Textural Soil Classification[1] which we can use to reproduce the original diagram published by the United Stated Department of Agriculture.

Firstly let us load the packages and data:

# Load the required libraries
library(ggtern)
library(plyr)
library(grid)

# Load the Data. (Available in ggtern 1.0.3.0 next version)
data(USDA)

# Put tile labels at the midpoint of each tile.
USDA.LAB = ddply(USDA, 'Label', function(df) {
    apply(df[, 1:3], 2, mean)
})

# Tweak
USDA.LAB$Angle = 0
USDA.LAB$Angle[which(USDA.LAB$Label == 'Loamy Sand')] = -35

Reconstructing the USDA’s Original Plot

Now let us construct the plot from the prepared data

# Construct the plot.
ggplot(data = USDA, aes(y=Clay, x=Sand, z=Silt)) +
  coord_tern(L="x",T="y",R="z") +
  geom_polygon(aes(fill = Label), 
               alpha = 0.75, size = 0.5, color = 'black') +
  geom_text(data = USDA.LAB,
            aes(label = Label, angle = Angle),
            color = 'black',
            size = 3.5) +
  theme_rgbw() +
  theme_showsecondary() +
  theme_showarrows() +
  custom_percent("Percent") +
  theme(legend.justification = c(0, 1),
        legend.position      = c(0, 1)) +
  labs(title = 'USDA Textural Classification Chart',
       fill  = 'Textural Class',
       color = 'Textural Class')

plot of chunk unnamed-chunk-2

Comparison to Existing Format

The above reproduction looks considerably better than the originally published format [1].

plot of original

Adding Additional Points

A number of people have asked how to add additional points, try the following:

  df <- data.frame(SAND=runif(10),SILT=runif(10),CLAY=runif(10))
  last_plot() + geom_point(data=df,aes(y=CLAY,x=SAND,z=SILT))

References

[1] Unknown-Author, Soil Mechanics Level 1, Module 3, USDA Textural Classification Study Guide, United States Department of Agriculture, 1987.
[Bibtex]
@Book{usda,
Title = {Soil Mechanics Level 1, Module 3, USDA Textural Classification Study Guide},
Author = {Unknown-Author},
Publisher = {United States Department of Agriculture},
Year = {1987},
Owner = {Nick Hamilton},
Timestamp = {20140116}
}
Facebooktwitterredditlinkedinmail
Comments
  1. Abdelhamid Elshater
  2. Renata
  3. Nicholas Hamilton
  4. Rodrigo
    • Nicholas Hamilton
      • Raph
        • Nicholas Hamilton
          • Raph
  5. Ken
    • Nicholas Hamilton
      • Ken
        • Songchao
          • Ken
  6. Tyler
    • Nicholas Hamilton
      • Tyler
  7. Songchao
    • Nicholas Hamilton
      • Songchao
  8. Kate
  9. iva and debt management
  10. Judi Ayam Online
  11. Leandro
  12. cara daftar sbobet casino
  13. Dessie
  14. sbobet casino indonesia
  15. Sbomabos
  16. bukauser.com
  17. depoxito.com
  18. mahabet.com
  19. linksbo

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.