texture: ASTM soil texture analysis

Description Usage Arguments Value Author(s) References See Also Examples

View source: R/texture.R

Description

Calculates the particle size distribution and both DIN and USDA texture classes from a series of hydrometer readings according to ASTM D422-63 (2007).

Usage

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texture(reading, ...)

## S3 method for class 'formula'
texture(formula, data = NULL, ...)

## Default S3 method:
texture(
  reading,
  blank,
  time,
  temp,
  conc = 50,
  Gs = 2.65,
  hydrometer = "auto",
  model = "auto",
  plot = F,
  ...
)

## S3 method for class 'texture'
print(x, ...)

## S3 method for class 'texture'
plot(x, ...)

Arguments

reading

a numeric vector of data values providing the hydrometer readings at the bottom of the meniscus.

...

further arguments to be passed to texture() (currently not used), print(), or plot().

formula

an object of class 'formula' of the form reading ~ blank + time + temp.

data

a data frame containing the variables in formula.

blank

a numeric vector containing the blank readings taken in 5 g/L sodium hexametaphosphate solution (composite correction).

time

a numeric vector containing the time passed since the beginning of the measurement in minutes.

temp

an integer vector containing the measured temperature.

conc

the concentration of the soil solution, default is 50 g/L as proposed in the ASTM guideline.

Gs

specific gravity of the suspension.

hydrometer

a character string specifying the hydrometer used; accepted values are "auto" for auto-detection (default), "151H", and "152H".

model

string is passed to drm(), "auto" chooses the best fitting model automatically.

plot

logical; if TRUE the particle size distribution is plotted.

x

an object of class 'texture'.

Value

texture returns an object of class 'texture. The functions print() and plot() are available to retrieve the soil texture classes and the particle size distribution, respectively.

An object of class 'texture' is a list containing the following components:

meta Measurement meta data
distribution data frame providing the particle size distribution
model information on the fitted drm model
din Main DIN texture classes
usda Main USDA texture classes

Author(s)

Zacharias Steinmetz

References

ASTM D422-63 (2007). Standard Test Method for Particle-Size Analysis of Soils. Technical standard. ASTM International, West Conshohocken, PA. Available from http://www.astm.org/Standards/D422.htm

See Also

Other texture: clayloam

Examples

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data(clayloam)

## Default method
attach(clayloam)
texture(reading, blank, time, temperature)
detach(clayloam)

## Formula interface
texture(reading ~ blank + time + temperature, clayloam)

envalysis documentation built on March 6, 2021, 1:07 a.m.