Querying a data frame or data.table
On Dec 3, 2010, at 3:44 AM, Michael Bedward wrote:
Sounds just like the subset function (?) x <- as.data.frame(matrix(sample(5, 100, rep=TRUE), ncol=10)) subset(x, )
With data,table:
require(data.table)
> xd <- as.data.table(x)
> xd[ V1 > 3 & V2 < 5 , ]
V1 V2 V3 V4 V5 V6 V7 V8 V9 V10
[1,] 4 2 4 1 2 3 1 3 2 4
[2,] 4 1 2 2 4 2 3 2 4 3
[3,] 5 1 1 5 4 5 4 1 1 3
Michael On 3 December 2010 19:05, Santosh Srinivas <santosh.srinivas at gmail.com> wrote:
Hello Group, Is there an easy way to query a data.frame or data.table (this is fast!) for multiple conditions? I don't want to use a SQL kind of statement. I am looking for something like a subset with multiple conditions. Any tips of the like the binary search methodology used for data.table would also help. Thanks in advance. S
David Winsemius, MD West Hartford, CT