sqrtWayne.frink

View or download sqrtWayne.frink in plain text format


/** This is an attempt to convert the algorithm of Prof. Wayne at Princeton
    for arbitrary precision sqrt (which only allows integer arguments) to a
    more generalized algorithm that allows floating-point arguments.

    https://introcs.cs.princeton.edu/java/92symbolic/ArbitraryPrecisionSqrt.java.html

    Thanks to Jeremy Roach for the research.
*/

sqrt[n, digits] :=
{
   // Intial estimate.  Find smallest power of 2 >= sqrt[n]
   // TODO:  Make this work with arbitrary precision?  Or faster?
   initial = 2.^ceil[ln[n] / ln[2] / 2]
   //   println["initial is $initial"]

   t = initial
   precision = 1

   origPrecision = getPrecision[]
   try
   {
      while (precision <= 2 * digits)
      {
         setPrecision[1 + 2 * precision]
         t = (n/t + t) / 2.
         precision = precision * 2
      }

      setPrecision[digits]
      return 1. t
   }
   finally
      setPrecision[origPrecision]
}


    


View or download sqrtWayne.frink in plain text format

This is a program written in the programming language Frink.
For more information, view the Frink Documentation or see More Sample Frink Programs.

Alan Eliasen was born 18078 days, 11 hours, 41 minutes ago.