DexiContinuousScale is a RC class, derived from DexiScale,
representing continuous value scales in R.
low_pointnumeric. A bound for the quality interval [-Inf, low_point].
high_pointnumeric. A bound for the quality interval [high_point, +Inf].
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.
initialize(order = EnumOrder, ...)Initialize a DexiScale object.
to_string()Return a string representation of this scale for printing.
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.
An attribute associated with a continuous scale can take any single numeric value from
[-Inf, +Inf].
DexiContinuousScale defines two numeric bounds, called low_point and
high_point, such that low_point <= high_point. These values partition
preferentially ordered scales in three preferential classes ("qualities"):
"bad", "none" (in the sense of "neutral"), and "good".
For a scale with order = "ascending", the three corresponding intervals are
[-Inf, low_point], (low_point, high_point) and [high_point, +Inf].
For order = "descending", the order of qualities is reversed.
Scales with order = "none" have only one associated quality,
"none", for the whole range of values.
Continuous scales are supported in DEXi Suite software (DEXiWin), but not in older DEXi Classic software (DEXi).