Normalize
rescale-functions normalize
syntax
- normalize(a, mean, sd)
definition
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.
description
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.
conditions
The value type of attribute a and literals or parameters mean and sd must match.
example
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