Error(s) in re-building vignettes:
  ...
--- re-building ‘MatchingOrder.Rmd’ using rmarkdown
** Processing: /home/hornik/tmp/R.check/r-release-gcc/Work/PKGS/PSAboot.Rcheck/vign_test/PSAboot/vignettes/MatchingOrder_files/figure-html/lalonde-boxplot-1.png
2304x768 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 47516 bytes
Input file size = 47654 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5		IDAT size = 45386
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 5		IDAT size = 45386

Output IDAT size = 45386 bytes (2130 bytes decrease)
Output file size = 45464 bytes (2190 bytes = 4.60% decrease)

** Processing: /home/hornik/tmp/R.check/r-release-gcc/Work/PKGS/PSAboot.Rcheck/vign_test/PSAboot/vignettes/MatchingOrder_files/figure-html/lalonde-balance-1.png
2304x768 pixels, 8 bits/pixel, 256 colors in palette
Reducing image to 8 bits/pixel, grayscale
Input IDAT size = 37018 bytes
Input file size = 37924 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 30060
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5		IDAT size = 27987
  zc = 9  zm = 8  zs = 1  f = 5		IDAT size = 27757
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 1  f = 5		IDAT size = 27757

Output IDAT size = 27757 bytes (9261 bytes decrease)
Output file size = 27835 bytes (10089 bytes = 26.60% decrease)

** Processing: /home/hornik/tmp/R.check/r-release-gcc/Work/PKGS/PSAboot.Rcheck/vign_test/PSAboot/vignettes/MatchingOrder_files/figure-html/tutoring-boxplot-1.png
2304x768 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 43580 bytes
Input file size = 43718 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5		IDAT size = 41812
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 5		IDAT size = 41812

Output IDAT size = 41812 bytes (1768 bytes decrease)
Output file size = 41890 bytes (1828 bytes = 4.18% decrease)

** Processing: /home/hornik/tmp/R.check/r-release-gcc/Work/PKGS/PSAboot.Rcheck/vign_test/PSAboot/vignettes/MatchingOrder_files/figure-html/tutoring-balance-1.png
2304x768 pixels, 8 bits/pixel, 256 colors in palette
Reducing image to 8 bits/pixel, grayscale
Input IDAT size = 37423 bytes
Input file size = 38329 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 28191
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5		IDAT size = 24894
  zc = 9  zm = 8  zs = 1  f = 5		IDAT size = 24686
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 1  f = 5		IDAT size = 24686

Output IDAT size = 24686 bytes (12737 bytes decrease)
Output file size = 24764 bytes (13565 bytes = 35.39% decrease)

--- finished re-building ‘MatchingOrder.Rmd’

--- re-building ‘PSAboot.Rmd’ using rmarkdown

Quitting from lines 134-143 [lalonde.boot] (PSAboot.Rmd)
Error: processing vignette 'PSAboot.Rmd' failed with diagnostics:
$ operator is invalid for atomic vectors
--- failed re-building ‘PSAboot.Rmd’

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

Error: Vignette re-building failed.
Execution halted