plotHSA_ray: plot the ray design from fit object returned by fitHSA_ray
In lshen1/drexplorer2: Dose-response Explorer2

plot the ray design from fit object returned by fitHSA_ray

plotHSA_ray(
  fit,
  cols = c(1, 2, 3),
  lwds = 3,
  xlim = NULL,
  ylim = NULL,
  xlab = NULL,
  ylab = "Relative viability",
  main = NULL,
  tag = NULL,
  type = c("line", "HSA", "Bliss", "se"),
  legend = TRUE,
  legend.cex = 0.6,
  plotSetup = TRUE,
  digit = 3
)

`fit`	the fitted result from fitHSA_ray().
`cols`	color corresponding to mixture, drugA, drugB.
`lwds`	line width.
`xlim`	x-axis limit.
`ylim`	y-axis limit.
`xlab`	x-axis label.
`ylab`	y-axis label.
`main`	figure title.
`tag`	title tag.
`type`	plot types.
`legend`	whether to show legend.
`legend.cex`	cex of the legend.
`plotSetup`	whether initiate a new figure; set to False when just to add curve as lines.
`digit`	Default is set to 3.