Try replacing the data output line with: 
warn sprintf "scale:         %.40f\nscaled_index:  %.40f\n"
               . "index:         %.40f\nadjusted_hue: %.40f\n\n",
                  $scale, $scaled_index, $index, $adjusted_hue;

[download]
then you'll see the following two outputs for the supposedly identical 0.3 cases: 
  adjusted_hue (75) equals 75
scale:         0.2999999999999999888977697537484345957637
scaled_index:  3.0000000000000000000000000000000000000000
index:         3.0000000000000000000000000000000000000000
adjusted_hue: 75.0000000000000000000000000000000000000000

  adjusted_hue (75) does not equal 75
scale:         0.3000000000000000444089209850062616169453
scaled_index:  3.0000000000000004440892098500626161694527
index:         3.0000000000000000000000000000000000000000
adjusted_hue: 75.0000000000000142108547152020037174224854

[download]

Dave.

In reply to Re: Why is this comparison failing? by dave_the_m
in thread Why is this comparison failing? by johnrcomeau

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