contrast.bayes {arm} | R Documentation |
Return a matrix of contrasts used in bayesglm
.
contr.bayes.unordered(n, base = 1, contrasts = TRUE) contr.bayes.ordered (n, scores = 1:n, contrasts = TRUE)
n |
a vector of levels for a factor, or the number of levels. |
base |
an integer specifying which group is considered the baseline
group. Ignored if contrasts is FALSE . |
contrasts |
a logical indicating whether contrasts should be computed. |
scores |
the set of values over which orthogonal polynomials are to be computed. |
These functions are adapted from contr.treatment
and contr.poly
in stats
package. The purpose for these functions are to keep
the baseline levels of categorical variables and thus to suit the use of
bayesglm
.
contr.bayes.unordered
is equivalent to contr.treatment
whereas
contr.bayes.ordered
is equivalent to contr.poly
.
Yu-Sung Su ys463@columbia.edu
C
,
contr.helmert
,
contr.poly
,
contr.sum
,
contr.treatment
;
glm
,
aov
,
lm
,
bayesglm
.
cat.var <- rep(1:3, 5) dim(contr.bayes.unordered(cat.var)) # 15*15 baseline level kept! dim(contr.treatment(cat.var)) # 15*14