test 08 in idiomatic PDL

t/x08.pl

@@ -98,54 +98,40 @@ sub cmap1_init {
 my $x = (sequence (XPTS) - int(XPTS / 2)) / int(XPTS / 2);
 $x *=  1.5
   if $rosen;
+my $xx = $x->dummy(1,YPTS);
 
 my $y = (sequence (YPTS) - int(YPTS / 2)) / int(YPTS / 2);
 $y += 0.5
   if $rosen;
+my $yy = $y->dummy(0,XPTS);
 
-my $z = zeroes (XPTS, YPTS);
-my ($i, $j);
-for ($i = 0; $i < XPTS; $i++) {
-  my $xx = $x->index ($i);
-  for ($j = 0; $j < YPTS; $j++) {
-    my $yy = $y->index ($j);
-    my $zz;
-    if ($rosen) {
-      $zz = (1 - $xx) ** 2 + 100 * ($yy - ($xx ** 2)) ** 2;
-      # The log argument may be zero for just the right grid.
-      if ($zz > 0.) {
-        $zz = log ($zz);
-      } else {
-        $zz = -5.; # -MAXFLOAT would mess-up up the scale
-      }
-    }
-    else {
-      my $r = sqrt ($xx * $xx + $yy * $yy);
-      $zz = exp (-$r * $r) * cos (2.0 * pi * $r);
-    }
-    $z->index ($i)->index ($j) .= $zz;
-  }
+my $z;
+if ($rosen) {
+  $z = (1 - $xx) ** 2 + 100 * ($yy - ($xx ** 2)) ** 2;
+  # The log argument may be zero for just the right grid.
+  $z = log ($z);
 }
-
-sub mymin { $_[0] < $_[1] ? $_[0] : $_[1] }
-sub mymax { $_[0] > $_[1] ? $_[0] : $_[1] }
-
+else {
+  my $r = sqrt ($xx * $xx + $yy * $yy);
+  $z = exp (-$r * $r) * cos (2.0 * pi * $r);
+}
+$z->inplace->setnonfinitetobad;
+$z->inplace->setbadtoval(-5); # -MAXFLOAT would mess-up up the scale
+
+my (@indexymin, @indexymax);
+my $i = sequence( XPTS );
+my $square_root = sqrt( 1. - hclip( ( ( $i - $x0 ) / $a ) ** 2, 1 ) );
+# Add 0.5 to find nearest integer and therefore preserve symmetry
+# with regard to lower and upper bound of y range.
+my $indexymin = lclip( 0.5 + $y0 - $b * $square_root, 0 )->indx;
+# indexymax calculated with the convention that it is 1
+# greater than highest valid index.
+my $indexymax = hclip( 1 + ( 0.5 + $y0 + $b * $square_root ), YPTS )->indx;
 my $zlimited = zeroes (XPTS, YPTS);
-my (@indexymin, @indexymax, @zlimited);
 for my $i ( $indexxmin..$indexxmax-1 ) {
-  my $square_root = sqrt( 1. - mymin( 1, ( ( $i - $x0 ) / $a ) ** 2 ) );
-  # Add 0.5 to find nearest integer and therefore preserve symmetry
-  # with regard to lower and upper bound of y range.
-  $indexymin[$i] = mymax( 0, ( 0.5 + $y0 - $b * $square_root ) );
-  # indexymax calculated with the convention that it is 1
-  # greater than highest valid index.
-  $indexymax[$i] = mymin( YPTS, 1 + ( 0.5 + $y0 + $b * $square_root ) );
-  for my $j ($indexymin[$i]..$indexymax[$i]-1) {
-    $zlimited->index($i)->index($j) .= $z->index($i)->index($j);
-  }
+  my $j = [ $indexymin->at($i), $indexymax->at($i) ];
+  $zlimited->index($i)->slice($j) .= $z->index($i)->slice($j);
 }
-my $indexymin = pdl \@indexymin;
-my $indexymax = pdl \@indexymax;
 
 my $zmin = min ($z);
 my $zmax = max ($z);