[R] C module causing rounding errors?

[Duncan Murdoch]

Joseph N. Paulson wrote:
> Hi all!
>
> I am currently writing a C-module for a for loop in which I permute columns
> in a matrix (bootstrapping) and I send a couple of variables into C
> initially. All of it is working, except the initial values I send to R are
> rounded/truncated (I believe rounded).
>
> I am using a 32 bit machine to compile, I am using (I believe) 32 bit R....
>
> While debugging I print the values I am sending to C, and then I print the
> same values using Rprintf and the number gets rounded to 10^-6, which is
> actually causing some errors for me. Is there any way to correct/prevent the
> error?
>
>
> sample output from R
>
>  [1,]  1.0000000
>  [2,]  1.0256242
>  [3,]  1.1826277
>  [4,] -0.6937246
>  [5,]  1.3633604
>
> sample output from C
> 1.000000
> 1.025624
> 1.182628
> 0.693725
> 1.363360
>   

It looks as though you are confusing the display of numbers with their 
internal values.  R is printing 7 decimal places, C is printing 6.  As 
far as we can tell, that's the only difference.

Duncan Murdoch
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