[R] machine precision problem

David Winsemius dwinsemius at comcast.net
Mon Feb 22 15:15:45 CET 2010

On Feb 21, 2010, at 1:37 PM, wendy wrote:

> Dear all,
> I am analysising a set of gene expression data using multiplicative  
> Gaussian
> Kernel function. I calculated the kernels between two gene sets with  
> 20000
> genes for each set. The kernels are less than 1, therefore the  
> product of
> the kernels is out of the minimum precision in R. I wonder if there  
> is a way
> to lowering the minimum double precision in R. I am using R version  
> 2.10.1.

Have you considered other strategies, e.g. summing the logs and  

Your proposed solution would involve rewriting R. There is no switch  
to throw that would increase the width of doubles.


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