Feature extraction: percentage of missing values

A good quality of 3d scans is crucial for an assessment of similarity of striation marks between different bullets. Here, we measure the percentage of missing values in the scan. Generally, a higher percentage of missing values is associated with a lower scan quality.

extract_na(x3p)

Arguments

x3p

scan in x3p format

Value

percentage of missing values in the surface matrix of the scan

Examples

data(fau277_bb_l2)
extract_na(fau277_bb_l2) # this scan has a particularly high percentage of missing values
#> [1] 38.26887
extract_na(fau001_ba_l1) # good scan
#> [1] 13.83538