R-value

R-value can refer to:

Properties of materials:
- R-value (insulation), the efficiency of insulation of a house
- R-value (soils), stability of soils and aggregates for pavement construction
r-value, in computer science, a value that does not have an address in a computer language
R-factor (crystallography), a measure of the agreement between the crystallographic model and the diffraction data
In statistics, r (or r value) refers to the Pearson product-moment correlation coefficient, often called simply correlation coefficient
In ophthalmic optics, r-value refers to the distance between the segment optical center and the segment top

See also