ClassifyEqualInterval - ObjectVision/GeoDMS GitHub Wiki

Classify functions ClassifyEqualInterval

• ClassifyEqualInterval(a, domain unit)
• ClassifyEqualInterval(values, count, domain unit)

Since GeoDMS 20.20.0 the second form classifies a value-count table that was calculated before, with values and count the two subitem of a weeded_counts result. Use it when more than one result is derived from the same scan of a, since the calculation cache then calculates that scan once; the GeoDMS GUI uses it for the classification it generates for a map layer without a configured Classification. Below 4096 distinct values it gives the same class breaks as the two argument form; above it they can differ, because weeded_counts merges values that the two argument form counts separately.

ClassifyEqualInterval(a, domain unit) results in a data item with class breaks, based on an equal interval distribution of classes. The resulting values unit is the values unit of data item a, the resulting domain unit is the domain unit argument.

• a: numeric data item to be classified
• domain unit: determining the number of class breaks.

An equal distribution of classes means the data item to be classified is split up in classes with, as far as possible, an equal interval size of each class.

The same function can also be applied from the GUI, by requesting the Palette Editor of a map layer and activating the Classify > Equal Interval classification.

The ClassifyEqualInterval results in a set of ClassBreaks that can be used in the classify function to classify a data item.

• data item a with Numeric value type
• domain unit with value type from group CanBeDomainUnit

7.019

attribute<nrPersons> classifyEiNrInh (inh_4K) := ClassifyEqualInterval(NrInh, inh_4K);

Table inh_4K, nr of rows = 4

Table District, nr of rows = 15