Description Usage Arguments Value Author(s) References See Also Examples
The function optimises 4-parameter van Genuchten particle size distribution function of Zhuang et al(2001).
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | zhuang4(data = NULL, D = NULL, fr = NULL, p = NULL, group = NULL,
a = 1, b = 1, e = 1e-05, z = 1)
## Default S3 method:
zhuang4(data = NULL, D = NULL, fr = NULL, p = NULL,
group = NULL, a = 1, b = 1, e = 1e-05, z = 1)
## S3 method for class 'zhuang4'
plot(x, main = "Particle Size Distribution Function",
xlab = "Particle Diameter", ylab = "Fraction", ...)
## S3 method for class 'zhuang4'
coef(object, ...)
## S3 method for class 'zhuang4'
predict(object, D, ...)
|
data |
a dataframe of Particle Size Distribution. It can have column names of diameter of the particles "D" [mm], and fraction of the particles "fr" that ranges from 0-1. |
D |
character. The corresponding diameter in the data. |
fr |
character. The corresponding fraction of the particles. |
p |
porosity[g/m^3] |
group |
character. The name of the group variables if the data is from different areas. |
a |
an initial value of 'a' parameter to be optimised |
b |
an initial value of 'b' parameter to be optimised |
e |
an initial value of 'e' parameter to be optimised |
z |
an initial value of 'z' parameter to be optimised |
x |
a return object of the function. |
main |
Title of the plot |
xlab |
x label of the plot |
ylab |
y label of the plot |
... |
Any other graphical parameter |
object |
Model output object |
PD: predicted fraction by mass of particles passing a particular diameter
sand: percentage of sand
clay: percentage of clay
silt: percentage of silt
a: optimised a parameter
b: optimised b parameter
e: optimised e parameter
z: optimised z parameter
George Owusu
Zhuang, J., Jin, Y., & Miyazaki, T. (2001). Estimating water retention characteristic from soil particle-size distribution using a non-similar media concept. Soil Sci., 166, 308-321.
zhuang3
, haverkamp
,lass3
,logarithmic
,
logistic2
, logistic3
,logistic4
,fredlund3
,
fredlund4
, jaky
,andersson
,gompertz
Other van-Genuchten functions: haverkamp
,
zhuang3
1 2 3 4 5 6 7 8 9 10 |
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.