[R] Re: [R-SIG-Mac]how much memory does one need...

Thomas Lumley tlumley at u.washington.edu
Mon Oct 1 18:38:40 CEST 2001

On Sat, 29 Sep 2001, David A Richmond wrote:
> Several questions arise from this problem: 1) how do I determine how much
> memory is free within the program?, 2) how do I determine how much memory
> is being consumed by a given object?, 3) how do I force R to create a
> matrix as a single rather than a double?

1) gc() or memory.profile()

2) Not well-defined in general, but for a matrix it is usually 8 bytes per
element for real, 4 for integer (plus a fairly small fixed overhead).

3) You don't.  R doesn't have single precision.  as.single() is just a
request that when the object is passed to .C or .Fortran it should be
converted to single precision.


Thomas Lumley			Asst. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle

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