[R] reading in ASCII files
johann at ai.univie.ac.at
Mon Oct 1 09:50:49 CEST 2001
Mark Myatt wrote:
> Johann Petrak <johann at ai.univie.ac.at> writes:
>>- factors/levels are created automatically: often, the possible
>> labels are known in advance and could immediately be
>> converted. This would save a lot of memory and time for
>> bigger files, I assume.
> You can use levels() and factor() to do this.
I know ... the point I wanted to make is that for
very big files, this is an awful waste of memory
everything gets first stored as strings and only
after being read in gets converted to levels.
I am currently trying to understand the R source code
to do it another way: first convert a single
ASCII file to several binary coded column-files,
then read in those columns needed using readBin.
This should allow greates flexibility when
files are really big.
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