xdata => \@xarray,
ydata => \@yarray,

##</code><code>##

# die Plotfelder/-hashe belegen und hash istart
$ii = -1;
for ($i = 0; $i <= $#yfeld; $i++) {
#   next if ($yfeld[$i] == 0);
   $ii = $ii + 1;
   print "$i $ii ";
   push(@ploty,$yfeld[$i]);
   push @{$istart{$ii}}, $istart[$i];
   push @{$ianz{$ii}}, $ianz[$i];
   if ($xfeld[$i] eq 'x') {
      push @{$plotx{$ii}}, @xfix;
      print "x\n";
   } elsif ($xfeld[$i] eq 'y') {
      push @{$plotx{$ii}}, @yfix;
      print "y\n";
   } else {
      push @{$plotx{$ii}}, $fnfeld[$xfeld[$i]]->{'fn'};
      print "$xfeld[$i]\n";
   }
}
print "\n";
print "2 $plotx{2}[3]\n";
print "3 $plotx{3}[3]\n";
print "5 $plotx{5}[3]\n"; # ?
print "6 $plotx{6}[3]\n";
print "7 $plotx{7}[3]\n"; # ?
print "8 $plotx{8}[3]\n"; # ?
print "9 $plotx{9}[3]\n";

##</code><code>##

0 0 0
1 1 0
2 2 y
3 3 y
4 4 0
5 5 5
6 6 x
7 7 5
8 8 5
9 9 y

##</code><code>##

2 3.640000E-04
3 3.640000E-04
Use of uninitialized value in concatenation (.) or string at test.pl line 590.
5 
6 3.640250E-04
Use of uninitialized value in concatenation (.) or string at test.pl line 592.
7 
Use of uninitialized value in concatenation (.) or string at test.pl line 593.
8 
9 3.640000E-04

##</code><code>##

ydata => $fnfeld[$ploty[$ii]]->{'fn'},