(anymap-ocol anymap)
The procedures bitmap-ocol, greymap-ocol, graymap-ocol and colormap-ocol are aliases being bound to this primitive procedure for compatibility.
The original column value of the anymap is returned (-1 for unknown/unspecified).
> (define bitmap (bitmap-create 100 100))
bitmap
> bitmap
#<bitmap orow:-1 ocol:-1 xres:-1 yres:-1 h:100 w:100>
> (anymap-ocol bitmap)
-1
>