correlation

 syntax

1. corr(a, b)
2. corr(a, b, partioning)

definition

1. corr(a, b) results in the correlation coefficient of attribute a and b.
2. corr(a, b, partioning) results in the correlation coefficient of attribute a and b, grouped by the partioning attribute. The domain unit of the resulting attribute is the values unit of the partioning attribute.

The value type of the values unit of the resulting attribute should be configured with the value type float32 or float64.

applies to

Attributes a and b with value types:

conditions

1. Attributes a and b need to match with regard to their value type.
2. Attributes a, b and partioning need to match with regard to their domain unit.

since version

5.15

1. parameter<float32> corrNrInhabitantsTemp: 
     expr = "corr(float32(City/NrInhabitants), City/avgDailyTemperature)"; 
     result = -0.89948
2. attribute<float32> corrNrInhabitantsTempRegion (RegionDomain):expr =
      "corr("
         " float32(City/NrInhabitants)"
         ", City/avgDailyTemperature"
         ", City/RegionNr"
      ")";