Issue #13 resolved
Cannot knit Lineage-Vignette.Rmd with error:
Quitting from lines 124-127 (Lineage-Vignette.Rmd) Error in mapply(save_plot, width = options$fig.width, height = options$fig.height, : zero-length inputs cannot be mixed with those of non-zero length
Knitting of HTML works without error.
Not sure what's up... I suspect some bug in knitr or rmarkdown.