The observations in the
evap.x
and
evap.y
data sets represent 46 consecutive days from June 6 through July 21.
From Freund (1979): "It is desired to estimate the daily amount of evaporation from the soil as a function of air temperature, relative humidity, and wind.
Since these factors vary considerably throughout the day it is not clear what function or aspect of these variables is most important.
For this reason the following ten variables relating to these factors are recorded."
Freund, R.J. (1979). Multicollinearity etc., Some "new" Examples. American Statistical Association Proceedings of Statistical Computing Section, pp. 111-112. Republished by permission of the American Statistical Association.