| hills | R Documentation |
The record times in 1984 (hills) for 35 Scottish hill races,
or in 2000 (hills2000) for 56 hill races. The hills2000
dataset is the subset of races2000 for which type
is hill.
data(hills)
data(hills2000)
distance, in miles (on the map)
total height gained during the route, in feet
record time in hours
record time in hours for females, in the
hills2000 dataset.
A.C. Atkinson (1986) Comment: Aspects of diagnostic regression analysis. Statistical Science 1, 397-402.
Also, in MASS library, with time in minutes.
The Scottish Running Resource, http://www.hillrunning.co.uk
A.C. Atkinson (1988) Transformations unmasked. Technometrics 30,
311-318. [ "corrects" the time for Knock Hill, in the hills
dataset, from 78.65 to 18.65. It
is unclear if this based on the original records.]
print("Transformation - Example 6.4.3")
pairs(hills, labels=c("dist\n\n(miles)", "climb\n\n(feet)",
"time\n\n(hours)"))
pause()
pairs(log(hills), labels=c("dist\n\n(log(miles))", "climb\n\n(log(feet))",
"time\n\n(log(hours))"))
pause()
hills0.loglm <- lm(log(time) ~ log(dist) + log(climb), data = hills)
oldpar <- par(mfrow=c(2,2))
plot(hills0.loglm)
pause()
hills.loglm <- lm(log(time) ~ log(dist) + log(climb), data = hills[-18,])
summary(hills.loglm)
plot(hills.loglm)
pause()
hills2.loglm <- lm(log(time) ~ log(dist)+log(climb)+log(dist):log(climb),
data=hills[-18,])
anova(hills.loglm, hills2.loglm)
pause()
step(hills2.loglm)
pause()
summary(hills.loglm, corr=TRUE)$coef
pause()
summary(hills2.loglm, corr=TRUE)$coef
par(oldpar)
pause()
print("Nonlinear - Example 6.9.4")
hills.nls0 <- nls(time ~ (dist^alpha)*(climb^beta), start =
c(alpha = .909, beta = .260), data = hills[-18,])
summary(hills.nls0)
plot(residuals(hills.nls0) ~ predict(hills.nls0)) # residual plot
pause()
hills$climb.mi <- hills$climb/5280
hills.nls <- nls(time ~ alpha + beta*dist + gamma*(climb.mi^delta),
start=c(alpha = 1, beta = 1, gamma = 1, delta = 1), data=hills[-18,])
summary(hills.nls)
plot(residuals(hills.nls) ~ predict(hills.nls)) # residual plot
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