as.character.clip_rect
                        Convert clipping spec into PDF string
as.character.pdf_dict   Render 'pdf_dict' as character string
as.character.pdf_stream
                        Convert 'pdf_stream' to character
as.character.pdf_translate
                        Convert scale/rotate/translate specification to
                        a PDF transformation string
clip_polygon            Define a clipping polygon for use as a 'clip'
                        argument
clip_rect               Define a clipping rectangle for use as a 'clip'
                        argument
create_pdf              Create an new PDF
pdf_bezier              Add a cubic bezier to a PDF doc
pdf_circle              Add a circle to a PDF doc
pdf_clip_polygon        Add a global clipping polygon to a PDF doc
pdf_clip_rect           Add a global clipping rectangle to a PDF doc
pdf_image               Add image to a PDF doc
pdf_line                Add a line to a PDF doc
pdf_newpage             Start a new page in a PDF odc
pdf_polygon             Add a polygon to a PDF doc
pdf_polyline            Add a polyline to a PDF doc
pdf_rect                Add a rectangle to a PDF doc
pdf_rotate              Modify global transformation matrix with
                        additional rotation
pdf_scale               Modify global transformation matrix with
                        additional scaling
pdf_text                Add text to a PDF doc
pdf_translate           Modify global transformation matrix with
                        additional translation
pgpar                   Create graphical parameters for PDF objects
print.pdf_doc           Print a 'pdf' object to the console
tf_rotate               Create a rotation specification (for use as
                        'tf' argument)
tf_scale                Create a scaling specification (for use as 'tf'
                        argument)
tf_translate            Create a translation specification (for use as
                        'tf' argument)
write_pdf               Write pdf to file or string
