| acid {assist} | R Documentation |
Lake Acidity Study
Description
The acid data frame has 112 rows and 4 columns of data derived based on the Eastern Lakes Survey of 1984 implemented by the Environmental Protection Agency of the USA.
Usage
data(acid)
Format
The data frame contains the following columns:
ph a numeric vector of surface pH values.
t1 a numeric vector of calcium concentrations in log10 milligrams per liter.
x1, x2 numeric vectors of the lakes' geographic locations.
Details
112 lakes are extracted in the southern Blue Ridge mountains area. The surface pH values were recorded together with the calcium concentration and geographic locations.
Source
Douglas, A. and Delampady, M. (1990), Eastern Lake Survey Phase I: Documentation for the Data Base and the Derived Data sets. Tech Report 160 (SIMS), Dept. Statistics, University of British Columbia.
References
Gu, C. and Wahba, G. (1993) Smoothing Spline ANOVA with component-wise Bayesian confidence intervals. Journal of Computational and Graphic Statistics 55, 353-368.