[R] Error because of large dimension

[Oliver Keyes]

Hey Hanna,

nrow and ncol in matrix() are integer-based, for the moment at least;
accordingly they have a maximum value. (3195*1290*495*35*35*35*15) is
actually larger than an integer can hold - you can test this with:

str((3195*1290*495*35*35*35*15))

Which shows that it's stored as a numeric value. And if you try
as.integer((3195*1290*495*35*35*35*15)) you'll get an NA - because
it's too large for an integer to hold.

You could try using the "bigmemory" package, which is designed to
handle very very large matrices (and other datatypes) but I believe
that handling is in terms of making sure you can store the thing by
storing it in a file if necessary - I'm not sure if it allows for
longs (which can store much larger values) for nrow and ncol and
indexing generally. So it may be that, for now, you're out of luck I'm
afraid :(.

On 24 January 2016 at 11:46, li li <hannah.hlx at gmail.com> wrote:
> Hi all,
>   I am doing some calculation with very large dimension. I need to create a
> matrix
> with three columns and a very large number of rows
> (3195*1290*495*35*35*35*15=1.312083e+15) i
> n order to allocate calculation result from a for loop.
> R does not allow me to create such a matrix because of the large dimension
> (see below). Is there a way to go around this?
>   Thanks very much!!
>      Hanna
>
>
>> matrix(0, 3195*1290*495*35*35*35*15, 3)
> Error in matrix(0, 3195 * 1290 * 495 * 35 * 35 * 35 * 15, 3) :
>   invalid 'nrow' value (too large or NA)
> In addition: Warning message:
> In matrix(0, 3195 * 1290 * 495 * 35 * 35 * 35 * 15, 3) :
>   NAs introduced by coercion
>>
>
>         [[alternative HTML version deleted]]
>
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-- 
Oliver Keyes
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