The function edit is generic. These functions
  are methods for spatial
  objects of class "ppp", "psp" and "im".
The spatial dataset name is converted to a data frame or array,
  and the text editor is invoked. The user can change the values of spatial
  coordinates or marks of the points in a point pattern,
  or the coordinates or marks of the segments in a segment pattern,
  or the pixel values in an image. 
  The names of the columns of marks can also be edited.
If name is a pixel image, it is converted to a matrix 
  and displayed in the same spatial orientation as if
  the image had been plotted.
Note that the original object name is not changed;
  the function returns the edited dataset.