[R] using edit to extract codes from vignette failed

[PO SU]

Dear expeRts,
    When i using the following code, i get a error as follows:



 edit(file=vignette("grobs",package = "grid"))
Error in edit.vignette(file = vignette("grobs", package = "grid")) : 
  argument "name" is missing, with no default


I investigated edit function, but still can't  get codes from a vignette, May you help me?


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PO SU
mail: desolator88 at 163.com 
Majored in Statistics from SJTU