Representation of and operations on multidimensional arrays
General representation of multidimensional arrays (with named dimnames, also called named arrays.)
parray(varNames, levels, values = 1, normalize = "none", smooth = 0) as.parray(values, normalize = "none", smooth = 0) data2parray(data, varNames = NULL, normalize = "none", smooth = 0) makeDimNames(varNames, levels, sep = "")
varNames |
Names of variables defining table; can be a right hand sided formula. |
levels |
Either 1) a vector with number of levels of the factors in varNames or 2) a list with specification of the levels of the factors in varNames. See 'examples' below. |
values |
Values to go into the array |
normalize |
Either "none", "first" or "all". Should result be normalized, see 'Details' below. |
smooth |
Should values be smoothed, see 'Details' below. |
data |
Data to be coerced to a 'parray'; can be 'data.frame', 'table', 'xtabs', 'matrix'. |
sep |
Desired separator in dim names; defaults to "". |
A named array object represents a table defined by a set of variables and their levels, together with the values of the table. E.g. f(a,b,c) can be a table with a,b,c representing levels of binary variable
If normalize="first" then for each configuration of all
other variables than the first, the probabilities are normalized to
sum to one. Thus f(a,b,c) becomes a conditional probability table
of the form p(a|b,c).
If normalize="all" then the sum over all entries of f(a,b,c)
is one.
If smooth is positive then smooth is added to
values before normalization takes place.
A a named array.
Søren Højsgaard, sorenh@math.aau.dk
t1 <- parray(c("gender","answer"), list(c('male','female'),c('yes','no')), values=1:4)
t1 <- parray(~gender:answer, list(c('male','female'),c('yes','no')), values=1:4)
t1 <- parray(~gender:answer, c(2,2), values=1:4)
t2 <- parray(c("answer","category"), list(c('yes','no'),c(1,2)), values=1:4+10)
t3 <- parray(c("category","foo"), c(2,2), values=1:4+100)
varNames(t1)
nLevels(t1)
valueLabels(t1)
## Create 1-dimensional vector with dim and dimnames
x1 <- 1:5
as.parray(x1)
x2 <- parray("x", levels=length(x1), values=x1)
dim(x2)
dimnames(x2)
## Matrix
x1 <- matrix(1:6, nrow=2)
as.parray(x1)
parray(~a:b, levels=dim(x1), values=x1)
## Extract parrays from data
## 1) a dataframe
data(cad1)
data2parray(cad1, ~Sex:AngPec:AMI)
data2parray(cad1, c("Sex","AngPec","AMI"))
data2parray(cad1, c(1,2,3))
## 2) a table
data2parray(UCBAdmissions,c(1,2), normalize="first")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.