I'm using S-Plus 7.0.3 under XP on a dual-Opteron box with 4 GB of RAM.
I'm trying to do a two-sample permutation test using large objects.
Specifically, I have two vectors: one has a length of 2315245 while the
other has a length of 3033371 -- tehse vectors represent geopotential
height errors from meteorological models under different conditions. I
want to assess the significance level of the RMS value of each vector
and I'm trying to use permutationTest2() from the resample library to do
this.
Aparently, S-Plus creates an array or indices for resampling as a first
step, but because my objects are so large, such an aray with anything
more than a few tens of replicates quickly becomes too large to fit
within the addressable memory of the XP 32-bit OS. I've tried various
ways of trimming down the memory requiremenets, but with no success. For
example, I thought I might be able to use addSamples(), but there are no
default methods to use on a permutationtest object. I've played with
block.size, but that doesn't help, either. I even tried using the
bigdata library, but the resample library doesn;t play well with bigdata
objects and, in any event, certainly doesn't create any bigdata objects
internally.
Do any of you know of a way around this?
Kim Elmore
--
Kim Elmore, OU/CIMMS/NSSL
"All of weather is divided into three parts:
Yes, No and Maybe. The greatest of these is Maybe."
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