Improving PostScript math accuracy and precision?

Don Lancaster · 2006-12-28T17:22:01+00:00

Can the math precision and accuracy of PostScriptbe improved? Its out-of-the-box six decimal pointreported answers were not quite good enough for atleast some of my Magic Sinewave research.A case can be made that more than six decimalresults would only lengthen font files without anymeasurable result in most graphic applications.But 31 bit plus sign math should be good for twobillion states, or over nine decimal points. Minuswhere they stopped in any of their transcendentalapproximation algorithms.Here's a preliminary experiment: The square rootof two in PS returns 1.41421 . Rounding to fourdecimal places and subtracting gives .0000135899.Combining the two returns 1.4142 1358 99. Comparedagainst the "real" answer of 1.4142 1356 23. Whichis right on at eight decimal places, and not too badat nine.A simple text reformatter that does the combinationsfor you should be possible. And based on our Gonzomergestr convenience operator.Again, you would have to compare exactly what youwanted against the individual algorithms in use for thefancier functions.More at and -- Many thanks,Don Lancaster voice phone: (928)428-4073Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552rss: email: Please visit my GURU's LAIR web site at

Dec 28, 2006 40 Replies

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Don Lancaster 19 years ago

The argument that there is no good display PostScript is largely offset by using Distiller to get an image in a second or two.

You are always close to an image even if it is not truly realtime.

Many thanks, Don Lancaster voice phone: (928)428-4073 Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552 rss: http://www.tinaja.com/whtnu.xml email: don@tinaja.com Please visit my GURU\'s LAIR web site at http://www.tinaja.com

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