[PD] directory of root canvas

[Orm Finnendahl]

Hi,

 sorry, this is probably trivial, but I can't seem to find the
solution: I use a self written external in a pd patch, which on setup
loads initialization data from subdirectories with relative pathnames
to the directory the patch lives in.

Loading the pd patch from a terminal within the patches' directory
leads to pd having this directory as the current directory with all
relative paths working from there. Loading the patch with
double-clicking it will lead to pd starting from it's default
directory and the relative pathnames don't work from within the
external's setup routine.

How is it possible to determine and then set pd's current/default
directory to the path, the external's root canvas is located at from
within the external?

--
Orm