whiteside | R Documentation |
Mr Derek Whiteside of the UK Building Research Station recorded the weekly gas consumption and average external temperature at his own house in south-east England for two heating seasons, one of 26 weeks before, and one of 30 weeks after cavity-wall insulation was installed. The object of the exercise was to assess the effect of the insulation on gas consumption.
whiteside
The whiteside
data frame has 56 rows and 3 columns.:
Insul
A factor, before or after insulation.
Temp
Purportedly the average outside temperature in degrees Celsius. (These values is far too low for any 56-week period in the 1960s in South-East England. It might be the weekly average of daily minima.)
Gas
The weekly gas consumption in 1000s of cubic feet.
A data set collected in the 1960s by Mr Derek Whiteside of the UK Building Research Station. Reported by
Hand, D. J., Daly, F., McConway, K., Lunn, D. and Ostrowski, E. eds (1993) A Handbook of Small Data Sets. Chapman & Hall, p. 69.
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.
require(lattice) xyplot(Gas ~ Temp | Insul, whiteside, panel = function(x, y, ...) { panel.xyplot(x, y, ...) panel.lmline(x, y, ...) }, xlab = "Average external temperature (deg. C)", ylab = "Gas consumption (1000 cubic feet)", aspect = "xy", strip = function(...) strip.default(..., style = 1)) gasB <- lm(Gas ~ Temp, whiteside, subset = Insul=="Before") gasA <- update(gasB, subset = Insul=="After") summary(gasB) summary(gasA) gasBA <- lm(Gas ~ Insul/Temp - 1, whiteside) summary(gasBA) gasQ <- lm(Gas ~ Insul/(Temp + I(Temp^2)) - 1, whiteside) coef(summary(gasQ)) gasPR <- lm(Gas ~ Insul + Temp, whiteside) anova(gasPR, gasBA) options(contrasts = c("contr.treatment", "contr.poly")) gasBA1 <- lm(Gas ~ Insul*Temp, whiteside) coef(summary(gasBA1))