Hi,
I have been using the QCA package, in particular the "eqmcc" function
and I am having some issues when trying to use this to minimise a
particular boolean function.
The boolean function in question has 16 variables, and I am providing
the full truth table for the function (65536 with 256 true entries),
in the following way :
library(QCA)
func_tt = read.table("func.tt",header=TRUE)
eqmcc(func_tt, outcome="O", expl.0=TRUE)
However, after calculating for a little while, the system throws up a
memory error :
Error in vector("double", length) :
cannot allocate vector of length 2130706560
However, looking at the memory usage, I seem to have far more than 2GB free.
Is there some kind of built-in limit on the size of the heap in R? If
so, is there some way I can extend this?
Does anyone have any insight into this? Perhaps I am doing something stupid?
Thanks
Matthew
It is a little stupid, but the length of a vector is limited to 2^31-1 entries on any platform. A matrix is stored as a vector, so the product of all dimensions is also limited to 2^31-1. Allan. Matthew Gwynne wrote:> Hi, > > I have been using the QCA package, in particular the "eqmcc" function > and I am having some issues when trying to use this to minimise a > particular boolean function. > > The boolean function in question has 16 variables, and I am providing > the full truth table for the function (65536 with 256 true entries), > in the following way : > > library(QCA) > > func_tt = read.table("func.tt",header=TRUE) > eqmcc(func_tt, outcome="O", expl.0=TRUE) > > However, after calculating for a little while, the system throws up a > memory error : > > Error in vector("double", length) : > cannot allocate vector of length 2130706560 > > > However, looking at the memory usage, I seem to have far more than 2GB free. > > Is there some kind of built-in limit on the size of the heap in R? If > so, is there some way I can extend this? > > Does anyone have any insight into this? Perhaps I am doing something stupid? > > Thanks > > Matthew > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >
But: > 2^31-1 # is more than the specified problem length [1] 2147483647 > 2130706560 You may be dealing with a system that is not facile at memory allocation. Windows? On Jul 22, 2009, at 9:16 AM, Allan Engelhardt wrote:> It is a little stupid, but the length of a vector is limited to > 2^31-1 entries on any platform. A matrix is stored as a vector, so > the product of all dimensions is also limited to 2^31-1. > > Allan. > > Matthew Gwynne wrote: >> Hi, >> >> I have been using the QCA package, in particular the "eqmcc" function >> and I am having some issues when trying to use this to minimise a >> particular boolean function. >> >> The boolean function in question has 16 variables, and I am >> providing >> the full truth table for the function (65536 with 256 true entries), >> in the following way : >> >> library(QCA) >> >> func_tt = read.table("func.tt",header=TRUE) >> eqmcc(func_tt, outcome="O", expl.0=TRUE) >> >> However, after calculating for a little while, the system throws up a >> memory error : >> >> Error in vector("double", length) : >> cannot allocate vector of length 2130706560 >> >> >> However, looking at the memory usage, I seem to have far more than >> 2GB free. >> >> Is there some kind of built-in limit on the size of the heap in R? If >> so, is there some way I can extend this? >> >> Does anyone have any insight into this? Perhaps I am doing >> something stupid? >> >> Thanks >> >> Matthew >> >> ______________________________________________ >> R-help at r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.David Winsemius, MD Heritage Laboratories West Hartford, CT