`data(bodyfat)`

- case
- Case number.
- brozek
- Percent body fat using Brozek's equation: 457/Density - 414.2
- siri
- Percent body fat using Siri's equation: 495/Density - 450
- density
- Density determined from underwater weighing (gm/cm**3).
- age
- Age (years).
- weight
- Weight (lbs).
- height
- Height (inches).
- neck
- Neck circumference (cm).
- chest
- Chest circumference (cm).
- abdomen
- Abdomen circumference (cm) ''at the umbilicus and level with the iliac crest''.
- hip
- Hip circumference (cm).
- thigh
- Thigh circumference (cm).
- knee
- Knee circumference (cm).
- ankle
- Ankle circumference (cm).
- biceps
- Biceps (extended) circumference (cm).
- forearm
- Forearm circumference (cm).
- wrist
- Wrist circumference (cm) ''distal to the styloid processes''.

K.W. Penrose, A.G. Nelson, A.G. Fisher (1985). Generalized body composition prediction
equation for men using simple measurement techniques. *Medicine and Science
in Sports and Exercise*, **17**, 189.

P. Royston, W. Sauerbrei (2004). Improving the robustness of fractional polynomial models by preliminary covariate transformation. Submitted.

data(bodyfat) bodyfat$height[bodyfat$case==42] <- 69.5 # apparent error bodyfat <- bodyfat[-which(bodyfat$case==39),] # cp. Royston $\amp$ Sauerbrei, 2004 mfp(siri ~ fp(age, df = 4, select = 0.1) + fp(weight, df = 4, select = 0.1) + fp(height, df = 4, select = 0.1), family = gaussian, data = bodyfat)