param-unused.R

#
# param-unused.R,  5 Feb 20
#
# Data from:
# The New {C Standard}: {An} Economic and Cultural Commentary
# Derek M. Jones
#
# Example from:
# Evidence-based Software Engineering: based on the publicly available data
# Derek M. Jones
#
# TAG C function_parameter parameter_unused


source("ESEUR_config.r")


pal_col=rainbow(3)

# params,unused_param,num_funcs
num_unused=read.csv(paste0(ESEUR_dir, "sourcecode/param-unused.csv.xz"), as.is=TRUE)


x=c(1:8)

max_y=max(num_unused$num_funcs)
plot(num_unused$num_funcs, log="y", col=pal_col[1],
	 ylim=c(1, max_y),
	 xlab="Parameters in definition/Unused parameters", ylab="Function definitions\n")

fun_mod=glm(log(num_unused$num_func) ~ x)

summary(fun_mod)

pred=predict(fun_mod)
lines(exp(pred), col=pal_col[1])

points(num_unused$unused_param, col=pal_col[2])

# Derek's wet-finger fit
pred_unused=sapply(x, function(X) sum(num_unused$num_funcs[X:8]/(7*(X:8))))

lines(pred_unused, col=pal_col[3])

# Linear regression of the actual data
est_mod=glm(log(num_unused$unused_param) ~ x)

# summary(est_mod)

pred=predict(est_mod)
lines(exp(pred), col=pal_col[2])

legend(x="bottomleft", legend=c("Parameters", "Unused parameters", "Wet finger fit model"), bty="n", fill=pal_col, cex=1.2)