[R] Beyond double-precision?

Gabor Grothendieck ggrothendieck at gmail.com
Sat May 9 18:24:50 CEST 2009


The following packages support high precision precision
arithmetic (and the last two also support exact arithmetic):

bc - interface to bc calculator
http://r-bc.googlecode.com

gmp - interface to gmp (gnu multiple precision)
http://cran.r-project.org/web/packages/gmp

rSymPy - interface to sympy computer algebra system
http://rsympy.googlecode.com

Ryacas - interface to yacas computer algebra system
http://ryacas.googlecode.com



On Fri, May 8, 2009 at 4:54 PM, joaks1 <joaks1 at gmail.com> wrote:
>
> I need to perform some calculations with some extremely small numbers (i.e.
> likelihood values on the order of 1.0E-16,000).  Even when using the
> double() function, R is rounding these values to zero.  Is there any way to
> get R to deal with such small numbers?
>
> For example, I would like to be able to calculate e^-10000 (i.e.
> exp(-10000)) without the result being rounded to zero.
>
> I know I can do it in Mathematica, but I would prefer to use R if I can.
> Any help would be appreciated!
>
> Many Thanks in Advance!
> --
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>
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