DexiDiscreteScale-class {DEXiR} | R Documentation |
DexiDiscreteScale
is a RC class, derived from DexiScale,
representing qualitative (symbolic, discrete, verbal) value scales in R. Such scales are
typical for DEXi models and are the only scale type supported by the DEXi software.
DEXiWin software supports both continuous and discrete scales.
An attribute associated with a discrete scale can take values from a finite (and usually small)
set of string values contained in the character vector values
. Additionally, each of these values is
associated with one of the qualities "bad"
, "none"
or "good"
.
The latter are contained in the character vector quality
,
which is of the same length as values
.
values
character. Vector of qualitative scale values.
Example: scale$values <- c("low", "medium", "high")
.
nvals
integer. Equal to length(values)
.
quality
character. Vector of qualities, corresponding to values
.
Should be the of the same length as values
.
Example: scale$quality <- c("bad", "none", "good")
.
descriptions
character. A vector of textual descriptions of the corresponding
values
. Should be of the same length as values
.
count()
Return the number of scale elements.
Equal to NA
for DexiScale
, 0
for DexiContinuousScale
, and
equal to nvals >= 0
for DexiDiscreteScale
.
equal(scl)
Check if this scale is equal to scale scl
. Needed for attribute linking.
full_range()
Return the vector that represents the full range of values on this scale.
Equal to NA
for DexiScale
and DexiContinuousScale
,
and 1 : scale$nvals
for DexiDiscreteScale
.
initialize(order = EnumOrder, ...)
Initialize a DexiScale
object.
is_discrete()
Logical: Is this scale discrete?
to_string()
Return a string representation of this scale for printing.
value_index(value)
Find the index of value
(character(1)) on this scale.
Equal to NA
for DexiScale
and DexiContinuousScale
.
With DexiDiscreteScale
objects, it returns a numeric index or NA
of value
in scale$values
.
value_quality(value)
Return the quality (preferential class) of value
on this scale:
one of the strings "bad"
, "none"
or "good"
.
Always "none"
for DexiScale
and scales with order = "none"
.
verify()
Check the correctnes of this scale object and its fields.
Result: error()
or TRUE
.
# Load "Car.dxi"
CarDxi <- system.file("extdata", "Car.dxi", package = "DEXiR")
Car <- read_dexi(CarDxi)
# For example, consider the scale of attribute PRICE
scl <- Car$attrib("PRICE")$scale
# Print fields and basic properties of scl
scl$verify()
scl$values
scl$quality
scl$descriptions
scl$nvals
scl$count()
scl$is_discrete()
scl$is_continuous()
scl$to_string()
scl$full_range()
# Find value indices
scl$value_index("medium")
scl$value_index("med")
# Is scl equal to the scale of BUY.PRICE?
scl$equal(Car$attrib("PRICE")$scale)