Retrieves metadata from filename with the help of a predefined 'pattern'
metainfo_from_filename(filename, pattern)
Takes a filename (character string) and retrieves metadata from the filename
by consulting a predefined pattern. The whole process is somewhat similar to
specifying a format of a datetime object (see strftime). The pattern is
specified by placeholders (in the argument pattern ), which are in turn
specified in a dataframe (in the argument search_pattern_dict). Run
get_srm4r("search_pattern_dict") to see what these argument currently are.