An extra grey line behind the quantile plot

[xuzhenwu]

I found an extra grey line behind the quantile plot, which is slightly different from the results in
https://flr-project.org/ggplotFL/reference/geom_flquantiles.html

data(ple4)
flq <- rnorm(250, catch(ple4), 200000)
ggplot(flq, aes(x=date, y=data)) +
  geom_flquantiles(probs=c(0.25, 0.75), fill="red", alpha=0.25)

[iagomosqueira]

geom_flquantiles assumes probs is of an odd length, and the middle value is taken to be a central tendency, usually the median (0.50) and shown using geom_line. This has now been corrected, and geom_line is not called if probs has an even length.

The examples on the website have now been corrected.

[iagomosqueira]

geom_flquantiles now sets size = 0 in call to GeomRibbon, so linestyle or colour specifications only affect GeomLine. probs should specify 2 values for the ribbon, and 3 to get line and ribbon. Examples now reflect this.