```{index} single: hdrcpy (PDL) ``` ```{index} single: PDL::hdrcpy ``` # hdrcpy Get or set whether the header travels with derived ndarrays. $pdl->hdrcpy(1); my $on = $pdl->hdrcpy; With the flag on, ndarrays made from `$pdl` by an operation get a deep copy of its header, and the flag; with it off - the default - they start without a header. It returns the setting, after any change.