2100c70dd6
bitmapped vectors of booleans (no NAs), coercion from and to logicals,
integers and integer subscripts; fast boolean operators and fast
summary statistics. With 'bit' vectors you can store true binary
booleans {FALSE,TRUE} at the expense of 1 bit only, on a 32 bit
architecture this means factor 32 less RAM and ~ factor 32 more speed
on boolean operations. Due to overhead of R calls, actual speed gain
depends on the size of the vector: expect gains for vectors of size >
10000 elements. Even for one-time boolean operations it can pay-off to
convert to bit, the pay-off is obvious, when such components are used
more than once. Reading from and writing to bit is approximately as
fast as accessing standard logicals - mostly due to R's time for
memory allocation. The package allows to work with pre-allocated
memory for return values by calling .Call() directly: when evaluating
the speed of C-access with pre-allocated vector memory, coping from
bit to logical requires only 70% of the time for copying from logical
to logical; and copying from logical to bit comes at a performance
penalty of 150%. the package now contains further classes for
representing logical selections: 'bitwhich' for very skewed selections
and 'ri' for selecting ranges of values for chunked processing. All
three index classes can be used for subsetting 'ff' objects (ff-2.1-0
and higher).
6 lines
402 B
Text
6 lines
402 B
Text
$NetBSD: distinfo,v 1.1 2018/03/06 17:06:28 minskim Exp $
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SHA1 (R/bit_1.1-12.tar.gz) = 1558824a8ec06179098cdc5ef69a4f06a852a535
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RMD160 (R/bit_1.1-12.tar.gz) = ab0bbd383c9bd1ee5beb8169cfee6c4c1afce937
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SHA512 (R/bit_1.1-12.tar.gz) = 635dd28d43fecb3b580155e02430d3c894cb8d443177ad0e7757ad0344f742405dd9d147758eda442ebae3fbf8bfb14c927659d9df417f40979a93d402e9ab99
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Size (R/bit_1.1-12.tar.gz) = 53737 bytes
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