[R] Displaying numerics to full double precision

[Ben Bolker]

Jeff Delmerico wrote:
> 
> I'm working on a shared library of C functions for use with R, and I want
> to create a matrix in R and pass it to the C routines.  I know R computes
> and supposedly stores numerics in double precision, but when I create a
> matrix of random numerics using rnorm(), the values are displayed in
> single precision, and also exported in single precision when I pass them
> out to my C routines.  An example is below:
> 
>> a <- matrix(rnorm(16, mean=10, sd=4), nrow=4)
>> a
>           [,1]      [,2]      [,3]      [,4]
> [1,] 14.907606 17.572872 19.708977  9.809943
> [2,]  9.322041 13.624452  7.745254  7.596176
> [3,] 10.642408  6.151546  9.937434  6.913875
> [4,] 14.617647  5.577073  8.217559 12.115465
>> storage.mode(a)
> [1] "double"
> 
> Does anyone know if there is a way to change the display or storage
> settings so that the values will be displayed to their full precision?  
> Or does rnorm only produce values to single precision? 
> 
> Any assistance would be greatly appreciated.
> 
> Thanks,
> Jeff Delmerico
> 

options("digits") # 7
options(digits=x)

  I may be mistaken, but I think the values are indeed exported
as double precision -- the issue here is just a display setting.

  Ben Bolker


-- 
View this message in context: http://www.nabble.com/Displaying-numerics-to-full-double-precision-tf4950807.html#a14178707
Sent from the R help mailing list archive at Nabble.com.