Soil Chemistry Properties Data

Description

Soil chemistry properties measured on a regular grid with 10 x 25 points spaced by 5 meters.

• COORD.X - X coordinate.

• COORD.Y - Y coordinate.

• SAND - Sand portion of the sample.

• SILT - Silt portion of the sample.

• CLAY - Clay portion of the sample.

• PHWATER - Soil pH at water.

• CA - Calcium content.

• MG - Magnesium content.

• K - Potassio content.

Usage

data(soil)

Format

a data.frame with 250 records and 9 variables.

Source

Bonat, W. H. (2016). Multiple Response Variables Regression Models in R: The mcglm Package. Journal of Statistical Software, submitted.

Examples

data(soil, package="mcglm")
neigh <- tri2nb(soil[,1:2])
Z1 <- mc_car(neigh)
# Linear predictor
form.ca <- CA ~ COORD.X*COORD.Y + SAND + SILT + CLAY + PHWATER
fit.ca <- mcglm(linear_pred = c(form.ca), matrix_pred = list(Z1),
               link = "log", variance = "tweedie", covariance = "inverse",
               power_fixed = FALSE, data = soil,
               control_algorith = list(max_iter = 500, tunning = 0.1))
summary(fit.ca)
# Conditional hypothesis test
mc_conditional_test(fit.ca, parameters = c("power11","tau11","tau12"),
                   test = 2:3, fixed = 1)
# Spatial autocorrelation
mc_compute_rho(fit.ca)

Results