cleveland.soil {agridat} | R Documentation

## Soil resistivity in a field

### Description

Soil resistivity in a field

### Format

A data frame with 8641 observations on the following 5 variables.

`northing`

  y ordinate

`easting`

  x ordinate

`resistivity`

  Soil resistivity, ohms

`is.ns`

  Indicator of north/south track

`track`

  Track number

### Details

Resistivity is related to soil salinity.

### Source

William Cleveland, (1993), Visualizing Data. Electronic version from StatLib: http://lib.stat.cmu.edu/datasets/

Cleaned version from Luke Tierney http://homepage.stat.uiowa.edu/~luke/classes/248/examples/soil

### Examples

    data(cleveland.soil)
    dat <- cleveland.soil

    # Similar to Cleveland fig 4.64
    ## require(latticeExtra)
    ## redblue <- colorRampPalette(c("firebrick", "lightgray", "#375997"))
    ## levelplot(resistivity ~ easting + northing, data = dat,
    ##           col.regions=redblue,
    ##           panel=panel.levelplot.points,
    ##           aspect=2.4, xlab= "Easting (km)", ylab= "Northing (km)",
    ##           main="cleveland")

    # 2D loess plot. Cleveland fig 4.68
    sg1 <- expand.grid(easting = seq(.15, 1.410, by = .02),
                       northing = seq(.150, 3.645, by = .02))
    lo1 <- loess(resistivity~easting*northing, data=dat, span = 0.1, degree = 2)
    fit1 <- predict(lo1, sg1)
    require(lattice)
    redblue <- colorRampPalette(c("firebrick", "lightgray", "#375997"))
    levelplot(fit1 ~ sg1$easting * sg1$northing,
              col.regions=redblue,
              cuts = 9,
              aspect=2.4, xlab = "Easting (km)", ylab = "Northing (km)",
              main="cleveland.soil - 2D smooth of Resistivity")

    # ----------------------------------------------------------------------------

    ## Not run:
      # 3D loess plot with data overlaid
      require(rgl)
      bg3d(color = "white")
      clear3d()
      points3d(dat$easting, dat$northing, dat$resistivity / 100,
               col = rep("gray50", nrow(dat)))
      rgl::surface3d(seq(.15, 1.410, by = .02),
                     seq(.150, 3.645, by = .02),
                     fit1/100, alpha=0.9, col=rep("wheat", length(fit1)),
                     front="fill", back="fill")
      rgl.close()

    ## End(Not run)

[Package agridat version 1.16 Index]