checkpoint: Make subjects wait for other subjects.
In hughjonesd/betr: betr: Behavioral Experiments Toolkit in R

Description Usage Arguments Details Value See Also Examples

Make subjects wait for other subjects.

1	checkpoint(wait_for = "all", name = "No name")

`wait_for`	"all", "none", "ever" or a vector of length N
`name`	optional name of the stage.

If wait_for is "all", then subjects must wait till all subjects in the experiment have arrived. If wait_for is "none" then checkpoint does nothing. If wait_for is "ever" then subjects wait forever (or until moved on manually by the experimenter, using next_stage).

If wait_for is a vector, then it is assumed to represent subject groups. So, if wait_for is vec then a subject with ID x will wait here until all subjects with IDs which(vec==vec[x]) have arrived at this stage.

A typical use of this might be mydf$groups[order(mydf$id),]

If all relevant subjects are ready, the subject moves on.

An object of class CheckPoint

Other stages: NEXT, WAIT, stage; form_stage; period; program; text_stage; timed

expt <- experiment(N=4)
groups <- c("A", "A", "B", "B")
s1 <- text_stage(page="<html><body><form action=''>
     <input type='submit' value='Next'></form></body></html>")

# wait for everyone:
add_stage(expt, period(), s1, checkpoint(), s1)

# players 1 and 2 wait for each other, so do 3 and 4:
add_stage(expt, period(), s1, checkpoint(c(1, 1, 2, 2)), s1)