P-profile (primary profile) is derived from the entire profile
- by removing very short wavelengths that are not included in the evaluation using the profile S-filter with the nesting index Nis (previously cut-off λs)
(the comparability is significantly improved by removing profile components < Nis) - and by excluding the nominal form using the least squares method on the line of the preselected form, e.g. a regression straight line.
Total height Pt (= total height of the P-profile) is the sum of the largest peak height and the largest pit depth of the P-profile within the evaluation length. The length of the evaluation length le (= reference length) must be specified.