Error(s) in re-building vignettes:
  ...
--- re-building ‘Cox-Beta-Model.Rmd’ using rmarkdown
── Attaching packages ────────────────────────────────── tidyverse 1.2.1 ──
✔ ggplot2 3.1.0       ✔ purrr   0.3.2  
✔ tibble  2.1.1       ✔ dplyr   0.8.0.1
✔ tidyr   0.8.3       ✔ stringr 1.4.0  
✔ readr   1.3.1       ✔ forcats 0.4.0  
── Conflicts ───────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
`geom_smooth()` using method = 'loess' and formula 'y ~ x'
`geom_smooth()` using method = 'loess' and formula 'y ~ x'
`geom_smooth()` using method = 'loess' and formula 'y ~ x'
`geom_smooth()` using method = 'loess' and formula 'y ~ x'
Quitting from lines 82-84 (Cox-Beta-Model.Rmd) 
Error: processing vignette 'Cox-Beta-Model.Rmd' failed with diagnostics:
VECTOR_ELT() can only be applied to a 'list', not a 'double'
--- failed re-building ‘Cox-Beta-Model.Rmd’

--- re-building ‘Distance_Measures.Rmd’ using rmarkdown
--- finished re-building ‘Distance_Measures.Rmd’

--- re-building ‘RandomForest-Model.Rmd’ using rmarkdown
── Attaching packages ────────────────────────────────── tidyverse 1.2.1 ──
✔ ggplot2 3.1.0       ✔ purrr   0.3.2  
✔ tibble  2.1.1       ✔ dplyr   0.8.0.1
✔ tidyr   0.8.3       ✔ stringr 1.4.0  
✔ readr   1.3.1       ✔ forcats 0.4.0  
── Conflicts ───────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
`geom_smooth()` using method = 'loess' and formula 'y ~ x'
`geom_smooth()` using method = 'loess' and formula 'y ~ x'
`geom_smooth()` using method = 'loess' and formula 'y ~ x'
`geom_smooth()` using method = 'loess' and formula 'y ~ x'
Quitting from lines 82-84 (RandomForest-Model.Rmd) 
Error: processing vignette 'RandomForest-Model.Rmd' failed with diagnostics:
VECTOR_ELT() can only be applied to a 'list', not a 'double'
--- failed re-building ‘RandomForest-Model.Rmd’

SUMMARY: processing the following files failed:
  ‘Cox-Beta-Model.Rmd’ ‘RandomForest-Model.Rmd’

Error: Vignette re-building failed.
Execution halted