urine package:cond R Documentation
Urine Data
Description:
The 'urine' data frame has 77 rows and 7 columns.
79 urine specimens were analyzed in an effort to determine if
certain physical characteristics of the urine might be related to
the formation of calcium oxalate crystals.
Usage:
data(urine)
Format:
This data frame contains the following columns:
'r' indicator of the presence of calcium oxalate crystals;
'gravity' the specific gravity of the urine, i.e. the density of
urine relative to water;
'ph' the pH reading of the urine;
'osmo' the osmolarity of the urine. Osmolarity is proportional to
the concentration of molecules in solution (mOsm).
'conduct' The conductivity of the urine. Conductivity is
proportional to the concentration of charged ions in
solution (mMho milliMho).
'urea' the urea concentration in millimoles per litre;
'calc' the calcium concentration in millimoles per litre.
Source:
The data were obtained from
Andrews, D. F. and Herzberg, A. M. (1985) _Data: A Collection
of Problems from Many Fields for the Student and Research Worker_,
Cambridge: Cambridge University Press.
References:
Davison, A. C. and Hinkley, D. V. (1997). _Bootstrap Methods and
Their Application _ (Example 7.8). Cambridge: Cambridge
University Press.
Examples:
data(urine)
summary(urine)
pairs(urine)
##
data(urine)
urine.glm <- glm(r ~ gravity + ph + osmo + conduct + urea + log(calc),
family = binomial, data = urine)
labels(coef(urine.glm))
urine.cond <- cond(urine.glm, log(calc))
##
## (large estimate of regression coefficient)
urine.glm <- glm(r ~ gravity + ph + osmo + conduct + urea + calc,
family = binomial, data = urine)
coef(urine.glm)
urine.glm <- glm(r ~ I(gravity * 100) + ph + osmo + conduct + urea + calc,
family = binomial, data = urine)
coef(urine.glm)
urine.cond <- cond(urine.glm, I(gravity * 100))