diff --git a/lib/PDL/Graphics/Gnuplot.pm b/lib/PDL/Graphics/Gnuplot.pm
index 74108ba..157e43e 100644
--- a/lib/PDL/Graphics/Gnuplot.pm
+++ b/lib/PDL/Graphics/Gnuplot.pm
@@ -5562,50 +5562,44 @@ our $footicsAbbrevs = _gen_abbrev_list(qw/axis border mirror in out scale rotate
 
 $_pOHInputs = {
     ## Simple cases - boolean, number, scalar
-    'b' => sub { ( (defined $_[1]) ? ($_[1] ? 1 : 0) : undef ); },
-    'n' => sub { ( (defined $_[1]) ? ($_[1] + 0)     : undef ); },
-    's' => sub { ( (defined $_[1]) ? "$_[1]"         : undef ); },
+    b => sub {return $_[1] if !defined $_[1]; $_[1] ? 1 : 0 },
+    n => sub {return $_[1] if !defined $_[1]; $_[1] + 0 },
+    s => sub {return $_[1] if !defined $_[1]; "$_[1]" },
 
     ## one-line list (can also be boolean)
-    'l' => sub { return undef unless(defined $_[1]);
-		 return "" unless(length($_[1]));                                 # false value yields false
+    l => sub { return $_[1] if !defined $_[1] or !length $_[1] or ref $_[1] eq 'ARRAY';
 		 return [$_[1]] if( (!ref($_[1])) && "$_[1]" =~ m/^\s*\-?\d+\s*$/); # nonzero integers yield true
 		 # Not setting a boolean value - it's a list (or a trivial list).
-		 return $_[1] if ref $_[1] eq 'ARRAY';
 		 # anything that's not an array ref (and not a number) gets put in the array
 		 return [$_[1]];
     },
 
     ## one-line list (no booleanity: scalars always get copied to the list)
-    'ln' => sub { return undef unless(defined $_[1]);
-		  return "" unless(length($_[1]));
-		  return [$_[1]] unless(ref($_[1]) eq 'ARRAY');
-		  return $_[1];
+    ln => sub { return $_[1] if !defined $_[1] or !length $_[1] or ref $_[1] eq 'ARRAY';
+                return [$_[1]];
     },
 
     ## one-line list (can also be boolean or hash)
-    'lh' => sub { return undef unless(defined $_[1]);
-		 return "" unless(length($_[1]));                                 # false value yields false
-		 return $_[1] if( (!ref($_[1])) && "$_[1]" =~ m/^\s*\-?\d+\s*$/); # nonzero integers yield true
+    lh => sub { return $_[1] if !defined $_[1] or !length $_[1]
+                  or ref $_[1] eq 'ARRAY' or ref $_[1] eq 'HASH'
+                  or ((!ref($_[1])) && "$_[1]" =~ m/^\s*\-?\d+\s*$/); # nonzero integers yield true
 		 # Not setting a boolean value - it's a list (or a trivial list).
-		 return $_[1] if ref $_[1] eq 'ARRAY' or ref $_[1] eq 'HASH';
 		 return [$_[1]];
-                },
+    },
 
     ## list or 2-PDL for a range parameter
-    'lr' => sub { return undef unless(defined $_[1]);
-		 return "" unless(length($_[1]));                                 # false value yields false
-		 return $_[1] if( (!ref($_[1])) && "$_[1]" =~ m/^\s*\-?\d+\s*$/); # nonzero integers yield true
-		 # Not setting a boolean value - it's a list (or a trivial list).
-		 return $_[1] if ref $_[1] eq 'ARRAY';
+    lr => sub { return $_[1] if !defined $_[1] or !length $_[1]
+                  or ((!ref($_[1])) && "$_[1]" =~ m/^\s*\-?\d+\s*$/) # nonzero integers yield true
+                  # Not setting a boolean value - it's a list (or a trivial list).
+                  or ref $_[1] eq 'ARRAY';
 		 return [$_[1]] if !$_[1]->$_isa('PDL');
 		 barf "PDL::Graphics::Gnuplot: range parser found a PDL, but it wasn't a 2-PDL (max,min)"
 		     unless( $_[1]->dims==1 and $_[1]->nelem==2 );
 		 return [$_[1]->list];
-                },
+    },
 
     ## cumulative list (delete on "undef")
-    'C' => sub { return undef unless(defined $_[1]);
+    C => sub { return $_[1] if !defined $_[1];
 		 return 0 unless($_[1]);                             # false value yields false
 		 return 1 if( $_[1] && "$_[1]" =~ m/^\s*-?\d+\s*$/); # nonzero integers yield true
 		 # Not setting a boolean value - it's a list, so append it.
@@ -5615,10 +5609,9 @@ $_pOHInputs = {
                 },
 
     ## set hash values
-    'H' => sub { return undef unless(defined $_[1]);
+    H => sub { return $_[1] if !defined $_[1];
 		 my $out = (ref $_[0] eq 'HASH') ? $_[0] : {};
 		 my $in = $_[1];
-		 return undef unless defined($in);
 		 if(ref($in) eq 'ARRAY') {
 		     my %h = (@$in);
 		     $in = \%h;
@@ -5644,8 +5637,8 @@ $_pOHInputs = {
 
     ## number-indexed list
     ##
-    'N' => sub { my($old,$new,$h) = @_;
-		 return undef unless(defined $new);
+    N => sub { my($old,$new,$h) = @_;
+		 return $_[1] if !defined $_[1];
 		 my $out = (ref($old) eq 'ARRAY') ? $old : [];
 
                  # Split strings into lists if necessary.
@@ -5680,8 +5673,8 @@ $_pOHInputs = {
 
     ## <foo>tics option list
     ## (For valid hash keys, see footicsAbbrevs definition above)
-    'lt' => sub { my($old, $new, $h, $fieldname) = @_;
-		  return undef unless(defined($new));
+    lt => sub { my($old, $new, $h, $fieldname) = @_;
+		  return $_[1] if !defined $_[1];
 		  return 0 unless($new);
 		  if (!ref($new) or ref($new) eq 'ARRAY') {
 		      my @list;
@@ -5731,22 +5724,18 @@ $_pOHInputs = {
     },
 
     ## dashtype option
-    'dt' => sub { my($old, $new, $h, $fieldname) = @_;
+    dt => sub { my($old, $new, $h, $fieldname) = @_;
 		  if($gp_version < 5.0) {
 		      carp "WARNING: 'dashtype' is not supported by your <5.0 gnuplot.  Ignoring...\n";
 		      return $old;
 		  }
-		  if(ref $new  and   ref $new ne 'ARRAY') {
-		      barf "Error:  dashtype curve option requires a scalar or an array ref";
-		  }
+		  barf "Error: dashtype curve option requires a scalar or an array ref"
+                    if ref $new and ref $new ne 'ARRAY';
 		  return $new;
-    }
-
+    },
 };
 
 
-
-
 ##############################
 # _emitOpts
 #