Iron Ore Data

SUMMARY:

The iron.ore data frame is a spatial data set with 112 rows and 4 columns: easting, northing, ore, and residuals.

DATA DESCRIPTION:

The data frame contains the following columns:

ARGUMENTS:

easting
relative longitude position.
northing
relative latitude position.
ore
percent iron (Fe2O3) at location easting, northing.
residuals
residuals from a median polish fit to the data. These are analyzed in Cressie (1991) and Zimmerman and Zimmerman (1991).

The original data have been modified slightly (for confidentiality reasons) by multiplying by and adding unspecified constants. Grid spacing is 50 meters by 50 meters.

SOURCE:

The modified data appear in Cressie (1986) and also in Zimmerman and Zimmerman (1991).

REFERENCES:

Cressie, Noel. (1986). Kriging nonstationary data. Journal American Statistical Association, 81, 625-634.

Zimmerman, Dale L. and Zimmerman, M. Bridget. (1991). A comparison of spatial semivariogram estimators and corresponding ordinary kriging predictors. Technometrics, 33, 77-91.