get_chumbley: Compute a Chumbley test score

Description Usage Arguments References Examples

Description

Compute a Chumbley test score

Usage

1
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

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
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$plot
b2.gr$plot
# 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$resid, window=150, reps=5)
get_chumbley(b1$resid, b2$resid, window=150, reps=5)
get_chumbley(b1$resid, b2$resid, window=50, reps=12)

erichare/bulletr documentation built on May 16, 2019, 8:26 a.m.