func skillFactorListToScheduleStep(facs []factor.Factor, idx int) []sched.RunnableSchedule {
steps := []sched.RunnableSchedule{}
for _, f := range facs {
step := sched.NewStep(f.UpdateMessage, idx)
steps = append(steps, step)
}
return steps
}
// buildSkillFactorSchedule builds a full schedule that represents all the steps
// in a factor graph.
func buildSkillFactorSchedule(numPlayers int, sf skillFactors, loopMaxDelta float64) sched.RunnableSchedule {
// Prior schedule initializes the skill priors for all players and updates
// the performance
priorSchedule := sched.NewSequence(
sched.NewSequence(skillFactorListToScheduleStep(sf.skillPriorFactors, 0)...),
sched.NewSequence(skillFactorListToScheduleStep(sf.skillToPerformanceFactors, 0)...),
)
// Loop schedule iterates until desired accuracy is reached
var loopSchedule sched.RunnableSchedule
if numPlayers == 2 {
// In two player mode there is no loop, just send the performance
// difference and the greater-than.
loopSchedule = sched.NewSequence(
sched.NewStep(sf.performanceToPerformanceDifferencFactors[0].UpdateMessage, 0),
sched.NewStep(sf.greatherThanOrWithinFactors[0].UpdateMessage, 0),
)
} else {
// Forward schedule updates the factor graph in one direction
forwardSchedule := []sched.RunnableSchedule{}
// ... and the backward schedule in the other direction
backwardSchedule := []sched.RunnableSchedule{}
for i := 0; i < numPlayers-2; i++ {
forwardSteps := []sched.RunnableSchedule{
sched.NewStep(sf.performanceToPerformanceDifferencFactors[i].UpdateMessage, 0),
sched.NewStep(sf.greatherThanOrWithinFactors[i].UpdateMessage, 0),
sched.NewStep(sf.performanceToPerformanceDifferencFactors[i].UpdateMessage, 2),
}
forwardSchedule = append(forwardSchedule, forwardSteps...)
backwardSteps := []sched.RunnableSchedule{
sched.NewStep(sf.performanceToPerformanceDifferencFactors[numPlayers-2-i].UpdateMessage, 0),
sched.NewStep(sf.greatherThanOrWithinFactors[numPlayers-2-i].UpdateMessage, 0),
sched.NewStep(sf.performanceToPerformanceDifferencFactors[numPlayers-2-i].UpdateMessage, 1),
}
backwardSchedule = append(backwardSchedule, backwardSteps...)
}
// Combine the backward and forward schedule so that they are run in
// said order
combinedForwardBackwardSchedule := sched.NewSequence(
sched.NewSequence(forwardSchedule...),
sched.NewSequence(backwardSchedule...),
)
// Loop through the forward and backward schedule until the delta stops
// changing by more than loopMaxDelta
loopSchedule = sched.NewLoop(combinedForwardBackwardSchedule, loopMaxDelta)
}
innerSchedule := sched.NewSequence(
loopSchedule,
sched.NewStep(sf.performanceToPerformanceDifferencFactors[0].UpdateMessage, 1),
sched.NewStep(sf.performanceToPerformanceDifferencFactors[numPlayers-2].UpdateMessage, 2),
)
// Finally send the skill performances of all players
posteriorSchedule := sched.NewSequence(skillFactorListToScheduleStep(sf.skillToPerformanceFactors, 1)...)
// Combine all schedules into one runnable sequence
fullSchedule := sched.NewSequence(priorSchedule, innerSchedule, posteriorSchedule)
return fullSchedule
}