Many warnings when running `vpcstats()` on a binless VPC

[billdenney]

When running a vpc that looks like this:

vpc_plotprep <-
  observed(d_mod_pk_aug, x = TIME, y = AVALN, lloq = ALLOQ) %>%
  simulated(vpc_prep_aug, x = time, y = sim) %>%
  stratify(~TRTP) %>%
  predcorrect(pred = PRED) %>%
  binless(loess.ypc = TRUE) %>%
  vpcstats(qpred = c(0.1, 0.5, 0.9))

I get many of the following warnings. Are they concerning?

1: In .local(x, ...) : singularity problem
2: In rq.fit.sfn(x, y, tau = tau, rhs = rhs, control = control,  ... :
  tiny diagonals replaced with Inf when calling blkfct

The warnings appear to come from this code:

tidyvpc/R/vpcstats.R

Lines 1621 to 1663 in af467fe

	# Internal Function
	.sic.strat.ypc <- function(llam, quant) {
	a <- AIC(
	rqss(
	l.ypc ~
	qss(x, lambda=exp(llam)),
	tau=quant, na.action=na.exclude, data = strat.split[[i]]
	),
	k=-1
	)
	}
	.sic.strat <- function(llam, quant){
	a <- AIC(
	rqss(
	y ~
	qss(x, lambda=exp(llam)),
	tau=quant, na.action=na.exclude, data = strat.split[[i]]
	),
	k=-1
	)
	}
	.sic.ypc <- function(llam, quant){
	a <- AIC(
	rqss(
	l.ypc ~
	qss(x, lambda=exp(llam)),
	tau=quant, na.action=na.exclude, data = obs
	),
	k=-1
	)
	}
	.sic <- function(llam, quant){
	a <- AIC(
	rqss(
	y ~
	qss(x, lambda=exp(llam)),
	tau=quant, na.action=na.exclude, data = obs
	),
	k=-1
	)
	}

P.S. I'm having other issues, too. This could be related to something else in my work.