Error(s) in re-building vignettes:
--- re-building 'clustered.Rmd' using rmarkdown
Quitting from lines 11-40 (clustered.Rmd) 
Error: processing vignette 'clustered.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'clustered.Rmd'

--- re-building 'correlated.Rmd' using rmarkdown
Quitting from lines 11-39 (correlated.Rmd) 
Error: processing vignette 'correlated.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'correlated.Rmd'

--- re-building 'double_dot_extension.Rmd' using rmarkdown
Quitting from lines 11-40 (double_dot_extension.Rmd) 
Error: processing vignette 'double_dot_extension.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'double_dot_extension.Rmd'

--- re-building 'longitudinal.Rmd' using rmarkdown
Quitting from lines 11-39 (longitudinal.Rmd) 
Error: processing vignette 'longitudinal.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'longitudinal.Rmd'

--- re-building 'missing.Rmd' using rmarkdown
Quitting from lines 11-66 (missing.Rmd) 
Error: processing vignette 'missing.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'missing.Rmd'

--- re-building 'ordinal.Rmd' using rmarkdown
Quitting from lines 11-40 (ordinal.Rmd) 
Error: processing vignette 'ordinal.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'ordinal.Rmd'

--- re-building 'simstudy.Rmd' using rmarkdown
Quitting from lines 11-43 (simstudy.Rmd) 
Error: processing vignette 'simstudy.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'simstudy.Rmd'

--- re-building 'spline.Rmd' using rmarkdown
Quitting from lines 11-40 (spline.Rmd) 
Error: processing vignette 'spline.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'spline.Rmd'

--- re-building 'survival.Rmd' using rmarkdown
Quitting from lines 11-194 (survival.Rmd) 
Error: processing vignette 'survival.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'survival.Rmd'

--- re-building 'treat_and_exposure.Rmd' using rmarkdown
Quitting from lines 11-67 (treat_and_exposure.Rmd) 
Error: processing vignette 'treat_and_exposure.Rmd' failed with diagnostics:
there is no package called 'ggplot2'
--- failed re-building 'treat_and_exposure.Rmd'

SUMMARY: processing the following files failed:
  'clustered.Rmd' 'correlated.Rmd' 'double_dot_extension.Rmd'
  'longitudinal.Rmd' 'missing.Rmd' 'ordinal.Rmd' 'simstudy.Rmd'
  'spline.Rmd' 'survival.Rmd' 'treat_and_exposure.Rmd'

Error: Vignette re-building failed.
Execution halted