R help - Sep 2011 - storage and single-precision

I'm getting the impression from on-line docs that R cannot work with 
single-precision floating-point numbers, but that it has a pseudo-mode for 
single precision for communication with external programs.

I don't mind that R is using doubles internally, but what about storage? 
If all I need to store is single-precision (32-bit), can I do that?  When 
it is read back into R it can be converted from single to double (back to 
64-bit).

Furthermore, the data are numbers from 0.000 to 2.000 with no missing 
values that could be stored just as accurately as unsigned 16-bit integers 
from 0 to 2000.  That would be the best plan for me.

It looks like the ff package allows for additional formats, so I might try 
to use ff, but I still would like to get a better understanding of R's 
native capabilities in regard to representations of numbers both in RAM 
and in stored data files.

Thanks in advance.

Best,
Mike

--
Michael B. Miller, Ph.D.
Minnesota Center for Twin and Family Research
Department of Psychology
University of Minnesota

On 11-09-07 6:25 PM, Mike Miller wrote:
> I'm getting the impression from on-line docs that R cannot work with
> single-precision floating-point numbers, but that it has a pseudo-mode for
> single precision for communication with external programs.
>
> I don't mind that R is using doubles internally, but what about
storage?
> If all I need to store is single-precision (32-bit), can I do that?  When
> it is read back into R it can be converted from single to double (back to
> 64-bit).
>
> Furthermore, the data are numbers from 0.000 to 2.000 with no missing
> values that could be stored just as accurately as unsigned 16-bit integers
> from 0 to 2000.  That would be the best plan for me.
writeBin is quite flexible in converting between formats if you just 
want to store them on disk.  To use nonstandard formats in memory will 
require external support; it's not easy.

Duncan Murdoch
>
> It looks like the ff package allows for additional formats, so I might try
> to use ff, but I still would like to get a better understanding of R's
> native capabilities in regard to representations of numbers both in RAM
> and in stored data files.
>
> Thanks in advance.
>
> Best,
> Mike
>
> --
> Michael B. Miller, Ph.D.
> Minnesota Center for Twin and Family Research
> Department of Psychology
> University of Minnesota
>
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