Error(s) in re-building vignettes:
--- re-building ‘introduction.Rmd’ using knitr
Loading required package: knitr
Loading required package: kfigr
knitr hook "anchor" is now available
Loading required package: ggplot2
`stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Quitting from lines 26-28 (introduction.Rmd) 
Error: processing vignette 'introduction.Rmd' failed with diagnostics:
polygon edge not found
--- failed re-building ‘introduction.Rmd’

SUMMARY: processing the following file failed:
  ‘introduction.Rmd’

Error: Vignette re-building failed.
Execution halted