Document attribute "ratio" returned by counting_process()

[jdblischak]

I updated the documentation for counting_process() to match its latest behavior. The returned attribute is now ratio.

xref: #276, #281

Idea for future improvement: It would be a good idea to also document the attribute ratio in the documentation for sim_pw_surv() too. The counting_process() code describes the simple ratio of event counts as the "empirical ratio", so I assume that sim_pw_surv() must be doing something different to calculate its ratio.

simtrial/R/counting_process.R

Lines 151 to 158 in 85cdc8f

	# if `x` is generated by sim_pw_surv
	if ("generate_by_simpwsurv" %in% names(attributes(x))) {
	ratio <- attributes(x)$ratio
	} else {
	# if not, calcualte the emperical ratio
	ratio <- sum(x$treatment == arm) / sum(x$treatment != arm)
	}
	attr(ans, "ratio") <- ratio