in reply to significant digits in computations

This is slightly off-topic since the original poster was asking about fixed-point arithmetic, and not really significant digits, but....

It would be cool to have a perl library that would automatically apply the scientific "number of significant digits" rules. 

my $n1=new Number::Scientific(5500,3); #5500 w/ 3 significatn digits
my $n2=new Number::Scientific(3.141592,7) # pi w/ 7 siginificant digit
+s
my $n3=$n1*$n2;
my $n4=$n2/$n1;
my $n5=$n1+$n2;
print "$n3 $n4 $n5\n";

[download]
would output 17300 0.000571 5500. Unfortunately I don't think any such beast exists.

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RE: Re: significant digits in computations
by chromatic (Archbishop) on Jun 12, 2000 at 19:23 UTC
    What about Math::BigFloat? It's in the standard distribution since about 5.002, I think. Or do you mean something to track Significant Digits and make the results of their calculations return only the sigdigs?
[reply]
      What I am talking about is something that would track (and apply) significant digits internally. I could multiply a number with 2 significant digits by a number with 3 significant digits and when I went to display the results it would know that there were 2 significant digits and display apropriately without having to manually keep track of significant digits or decimal places myself.
[reply]

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