fit_data(\@array);
sub fit_data {
	my $refCopy=$_[0];
	*ydata=$refCopy;
	print "array contains: ",join(",",@ydata)," \n";
	print "last index is $#ydata \n";
}

##</code><code>##

use strict;
my @valueArr = (1,2,3,4);

fit_data(\@valueArr);
fit_dataLex(\@valueArr);
fit_dataGlobal(\@valueArr);

sub fit_data {
	no strict "vars";
	my $refCopy=$_[0];
	*ydata=$refCopy;
	print "array contains: ",join(",",@ydata)," \n";
	print "last index is $#ydata \n";
	#but you can't use strict on @ydata references 
}

#if we define @ydata with my, it's not in the glob table, but strict is happy.
sub fit_dataLex {
	use strict;
	my @ydata;
	
	my $refCopy=$_[0];
	*ydata=$refCopy;  #but @ydata not set
	print "array contains: ",join(",",@ydata)," \n";
	print "last index is $#ydata \n";
}

# if we create @ydata as global, we have to qualify it every time,
# and dirty our global space with 'local' vars.
@main::ydata = (); #to use a typeglob below, 
sub fit_dataGlobal {
	use strict;
	my $refCopy=$_[0];
	*ydata=$refCopy;
	print "array contains: ",join(",",@main::ydata)," \n";
	print "last index is $#main::ydata \n";}