ClassifyUniqueValues
Classify functions ClassifyUniqueValues
syntax
- ClassifyUniqueValues(a, Domain unit)
- ClassifyUniqueValues(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 | sub items]] 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. |
definition
ClassifyUniqueValues(a, domain unit) results in a Data item with class breaks, based on the unique values occurring in the data item a. 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.
description
The ClassifyUniqueValues function results in a number of class breaks, based on the number of rows of the domain unit argument. If the data item to be classified contains more unique values than this number, the resulting set is cut off at this number. If the data item to be classified contains fewer unique values, the resulting Data item is completed by repeating the highest unique value.
To create a new domain unit with all unique values occurring in the original data set once, use the Unique function.
This unique function works similarly to the unique values function in the GUI, which can be applied by requesting the Palette Editor of a map layer and activating the Classify > Unique values classification.
applies to
- data item a with Numeric Value type
- domain unit with value type from group CanBeDomainUnit
since version
7.019
example
attribute<nrPersons> classifyUvNrInh (inh_4K) := ClassifyUniqueValues(NrInh, inh_4K);
| classifyUvNrInh |
|---|
| 0 |
| 2 |
| 20 |
| 55 |
Table inh_4K, nr of rows = 4
| NrInh |
|---|
| 550 |
| 1025 |
| 300 |
| 200 |
| 0 |
| null |
| 300 |
| 2 |
| 20 |
| 55 |
| 860 |
| 1025 |
| 1025 |
| 100 |
| 750 |
Table District, nr of rows = 15