[R] Newbie question : selecting subset of a Matrix

[arun]

Hi,
Try this:
wok<-read.table(text="
  who  task
  joe task1
  joe task2
  joe task3
  jack task1
  jack task2
",sep="",header=TRUE,stringsAsFactors=FALSE)


wok2<- wok[wok[,1]=="joe" & wok[,2]!="task2",]
wok2

#  who  task
#1 joe task1
#3 joe task3
A.K.




----- Original Message -----
From: "thocar at free.fr" <thocar at free.fr>
To: r-help at r-project.org
Cc: 
Sent: Wednesday, November 7, 2012 5:20 PM
Subject: [R] Newbie question : selecting subset of a Matrix

I have a matrix, I would like to use it like I use where query on an SQL table

Let's say my matrix is

> wok
    who  task
1   joe task1
2   joe task2
3   joe task3
4  jack task1
5  jack task2

I want to extract a matrix that contains only rows where
    who = "joe" and task != "task2"

The result would be the following matrix

1   joe task1
2   joe task3

How can I do that with R ?

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