Error(s) in re-building vignettes:
  ...
--- re-building ‘how-to-use.Rmd’ using rmarkdown
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
[WARNING] Deprecated: --highlight-style. Use --syntax-highlighting instead.
--- finished re-building ‘how-to-use.Rmd’

--- re-building ‘plots-gallery.Rmd’ using rmarkdown

Quitting from plots-gallery.Rmd:1148-1150 [unnamed-chunk-47]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NULL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'plots-gallery.Rmd' failed with diagnostics:
Problem while computing stat.
ℹ Error occurred in the 1st layer.
Caused by error in `compute_layer()`:
! The package "MASS" is required for calculating 2D density.
--- failed re-building ‘plots-gallery.Rmd’

SUMMARY: processing the following file failed:
  ‘plots-gallery.Rmd’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
  ...
--- re-building ‘how-to-use.Rmd’ using rmarkdown
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
[WARNING] Deprecated: --highlight-style. Use --syntax-highlighting instead.
--- finished re-building ‘how-to-use.Rmd’

--- re-building ‘plots-gallery.Rmd’ using rmarkdown

Quitting from plots-gallery.Rmd:1148-1150 [unnamed-chunk-47]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NULL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'plots-gallery.Rmd' failed with diagnostics:
Problem while computing stat.
ℹ Error occurred in the 1st layer.
Caused by error in `compute_layer()`:
! The package "MASS" is required for calculating 2D density.
--- failed re-building ‘plots-gallery.Rmd’

SUMMARY: processing the following file failed:
  ‘plots-gallery.Rmd’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
--- re-building ‘how-to-use.Rmd’ using rmarkdown
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
[WARNING] Deprecated: --highlight-style. Use --syntax-highlighting instead.
--- finished re-building ‘how-to-use.Rmd’

--- re-building ‘plots-gallery.Rmd’ using rmarkdown

Quitting from plots-gallery.Rmd:1148-1150 [unnamed-chunk-47]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NULL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'plots-gallery.Rmd' failed with diagnostics:
Problem while computing stat.
ℹ Error occurred in the 1st layer.
Caused by error in `compute_layer()`:
! The package "MASS" is required for calculating 2D density.
--- failed re-building ‘plots-gallery.Rmd’

SUMMARY: processing the following file failed:
  ‘plots-gallery.Rmd’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
--- re-building 'how-to-use.Rmd' using rmarkdown
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
--- finished re-building 'how-to-use.Rmd'

--- re-building 'plots-gallery.Rmd' using rmarkdown

Quitting from plots-gallery.Rmd:1148-1150 [unnamed-chunk-47]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NULL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'plots-gallery.Rmd' failed with diagnostics:
Problem while computing stat.
ℹ Error occurred in the 1st layer.
Caused by error in `compute_layer()`:
! The package "MASS" is required for calculating 2D density.
--- failed re-building 'plots-gallery.Rmd'

SUMMARY: processing the following file failed:
  'plots-gallery.Rmd'

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
  ...
--- re-building ‘how-to-use.Rmd’ using rmarkdown
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
[WARNING] Deprecated: --highlight-style. Use --syntax-highlighting instead.
--- finished re-building ‘how-to-use.Rmd’

--- re-building ‘plots-gallery.Rmd’ using rmarkdown

Quitting from plots-gallery.Rmd:1148-1150 [unnamed-chunk-47]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NULL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'plots-gallery.Rmd' failed with diagnostics:
Problem while computing stat.
ℹ Error occurred in the 1st layer.
Caused by error in `compute_layer()`:
! The package "MASS" is required for calculating 2D density.
--- failed re-building ‘plots-gallery.Rmd’

SUMMARY: processing the following file failed:
  ‘plots-gallery.Rmd’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
  ...
--- re-building ‘how-to-use.Rmd’ using rmarkdown
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
[WARNING] Deprecated: --highlight-style. Use --syntax-highlighting instead.
--- finished re-building ‘how-to-use.Rmd’

--- re-building ‘plots-gallery.Rmd’ using rmarkdown

Quitting from plots-gallery.Rmd:1148-1150 [unnamed-chunk-47]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NULL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'plots-gallery.Rmd' failed with diagnostics:
Problem while computing stat.
ℹ Error occurred in the 1st layer.
Caused by error in `compute_layer()`:
! The package "MASS" is required for calculating 2D density.
--- failed re-building ‘plots-gallery.Rmd’

SUMMARY: processing the following file failed:
  ‘plots-gallery.Rmd’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
--- re-building 'how-to-use.Rmd' using rmarkdown
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
--- finished re-building 'how-to-use.Rmd'

--- re-building 'plots-gallery.Rmd' using rmarkdown

Quitting from plots-gallery.Rmd:1148-1150 [unnamed-chunk-47]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NULL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'plots-gallery.Rmd' failed with diagnostics:
Problem while computing stat.
ℹ Error occurred in the 1st layer.
Caused by error in `compute_layer()`:
! The package "MASS" is required for calculating 2D density.
--- failed re-building 'plots-gallery.Rmd'

SUMMARY: processing the following file failed:
  'plots-gallery.Rmd'

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
--- re-building 'how-to-use.Rmd' using rmarkdown
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  "lwd.ticks" is not a graphical parameter
--- finished re-building 'how-to-use.Rmd'

--- re-building 'plots-gallery.Rmd' using rmarkdown

Quitting from plots-gallery.Rmd:1148-1150 [unnamed-chunk-47]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NULL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'plots-gallery.Rmd' failed with diagnostics:
Problem while computing stat.
ℹ Error occurred in the 1st layer.
Caused by error in `compute_layer()`:
! The package "MASS" is required for calculating 2D density.
--- failed re-building 'plots-gallery.Rmd'

SUMMARY: processing the following file failed:
  'plots-gallery.Rmd'

Error: Vignette re-building failed.
Execution halted