R help - Apr 2011 - Allocation of memory to a data frame

Hello gRoup,

A while back I was advised that overallocating an object and filling
it up is better than rbind.

I am trying to optimize some code. I have the following object (empty
which I know in advance).
Is there an easy to create an empty data frame with 100,000 empty rows
based on the structure below?
> dput(d)
structure(list(A = character(0), B = character(0), C = numeric(0),
    D = character(0), E = character(0), F = character(0), G character(0),
    H = structure(numeric(0), class = "Date"), I = numeric(0),
    J = integer(0)), .Names = c("A", "B", "C",
"D", "E", "F",
"G", "H", "I", "J"), row.names =
integer(0), class = "data.frame")

I can use dataFrame in R.utils and do it explicitly but wondering if
there an easier way since I have the structure with me.

Thank you.

On 20.04.2011 09:46, santosh wrote:
> Hello gRoup,
>
> A while back I was advised that overallocating an object and filling
> it up is better than rbind.
>
> I am trying to optimize some code. I have the following object (empty
> which I know in advance).
> Is there an easy to create an empty data frame with 100,000 empty rows
> based on the structure below?
>
>> dput(d)
> structure(list(A = character(0), B = character(0), C = numeric(0),
>      D = character(0), E = character(0), F = character(0), G >
character(0),
>      H = structure(numeric(0), class = "Date"), I = numeric(0),
>      J = integer(0)), .Names = c("A", "B",
"C", "D", "E", "F",
> "G", "H", "I", "J"), row.names =
integer(0), class = "data.frame")

Replace the zeros by your number of rows?

Uwe Ligges


> I can use dataFrame in R.utils and do it explicitly but wondering if
> there an easier way since I have the structure with me.
>
> Thank you.
>
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