Compute a Chumbley test score

Compute a Chumbley test score

get_chumbley(y1, y2, window, reps = 3)

Arguments

window	width of the window (in indices) to consider for matching
reps	number of replicates to use in the evaluation
b1	vector of equi-distant toolmark values
b2	vector of equi-distant toolmark values

References

Chumbley, L. S., Morris, M. D., Kreiser, M. J., Fisher, C., Craft, J., Genalo, L. J., Davis, S., Faden, D. and Kidd, J. (2010), Validation of Tool Mark Comparisons Obtained Using a Quantitative, Comparative, Statistical Algorithm. Journal of Forensic Sciences, 55: 953–961. doi:10.1111/j.1556-4029.2010.01424.x

Examples

library(dplyr)

data(br411)
b1 <- get_crosscut(x = 250, bullet=br411)
b2 <- get_crosscut(x = 150, bullet = br411)
b3 <- get_crosscut(x = 10, bullet=br411)
b1.gr <- b1 %>% get_grooves(smoothfactor=30)
b2.gr <- b2 %>% get_grooves()
b3.gr <- b3 %>% get_grooves()
# check that the grooves are actually found:
b1.gr$plot
#> Warning: Removed 17 rows containing missing values (geom_point).
b2.gr$plot
#> Warning: Removed 17 rows containing missing values (geom_point).
# get signatures
b1 <- fit_loess(b1, b1.gr)$data
b2 <- fit_loess(b2, b2.gr)$data
b3 <- fit_loess(b3, b3.gr)$data
get_chumbley(b1$resid, b2$resid, window=150, reps=5)
#> Error in get_chumbley(b1$resid, b2$resid, window = 150, reps = 5): could not find function "get_chumbley"
get_chumbley(b1$resid, b2$resid, window=150, reps=5)
#> Error in get_chumbley(b1$resid, b2$resid, window = 150, reps = 5): could not find function "get_chumbley"
get_chumbley(b1$resid, b2$resid, window=50, reps=12)
#> Error in get_chumbley(b1$resid, b2$resid, window = 50, reps = 12): could not find function "get_chumbley"