rescale-functions normalize


  • normalize(a, mean, sd)


normalize(a, mean, sd) scales the attribute a to a normal distribution with as mean value the literal or parameter mean and as standard deviation the literal or parameter sd.

The resulting attribute has a new values-unit and the same domain-unit as attribute a.


The literals or parameters mean and sd have default values of zero and one.

To avoid rounding off errors in the normalize calculations, use a float32 of float64 value-type for the a, mean and sd arguments.


The value type of attribute a and literals or parameters mean and sd must match.


attribute<float32> normalize_NrInh (City) := normalize(City/NrInhabitants, 0f, 1f);
City/NrInhabitants normalize_nrInh
550 1.13
525 0.96
300 -0.48
500 0.80
200 -1.13
175 -1.29
null null

domain City, nr of rows = 7