[R] Understand Rcode- subset

[Thierry Onkelinx]

# logical vector, TRUE when record_type equals 1
id <- transact$record_type == 1
# lagged vector of id. TRUE is shifted one position ahead
id.lag <- c(id[2:length(id)], FALSE)
sub <- transact[id.lag, ]
# have a look at the row numbers
transact[id, ]
sub

Best regards,
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature
and Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
Kliniekstraat 25
1070 Anderlecht
Belgium

To call in the statistician after the experiment is done may be no
more than asking him to perform a post-mortem examination: he may be
able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher
The plural of anecdote is not data. ~ Roger Brinner
The combination of some data and an aching desire for an answer does
not ensure that a reasonable answer can be extracted from a given body
of data. ~ John Tukey


2015-08-24 17:32 GMT+02:00 Jhon Grey <butt_its_me op hotmail.com>:
> Hi!
>
> Thanks for pointing out the mistake.
>
> I am resubmitting my question as follows:
>
> Hi!
> I am facing a problem in understanding the R-Code
> Suppose I have a transactional dataset named- "transact" with its values
> like following:
> customer_ID
> <-c(10000000,10000000,10000000,10000000,10000000,10000000,10000000,10000000,10000000,10000005,10000005,10000005,10000005,10000005,10000005,10000007,10000007,10000007,10000007,10000007,10000007,10000007,10000007,10000013,10000013)
> shopping_pt <- c(1,2,2,3,4,5,6,7,8,9,1,2,3,4,5,6,1,2,3,4,5,6,7,8,1,2)
> record_type <- c(0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0)
> transact <- data.frame(customer_ID, shopping_pt, record_type)
>
> How does the following code work
> id<-transact$record_type==1
> sub<-transact[c(id[2:length(id)],FALSE),]
> id<-c(id[3:length(id)],FALSE,FALSE)
> sub2<-transact[id,]
> Thanks in advance!
>
>> Date: Mon, 24 Aug 2015 15:25:09 +0200
>> Subject: Re: [R] Understand Rcode- subset
>> From: thierry.onkelinx op inbo.be
>> To: butt_its_me op hotmail.com
>> CC: r-help op r-project.org
>
>>
>> Posting in HTML mangles up your code, making it hard to read. Please
>> resend your question in plain text and make the code reproducible. See
>> http://adv-r.had.co.nz/Reproducibility.html for more details on that.
>> ir. Thierry Onkelinx
>> Instituut voor natuur- en bosonderzoek / Research Institute for Nature
>> and Forest
>> team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
>> Kliniekstraat 25
>> 1070 Anderlecht
>> Belgium
>>
>> To call in the statistician after the experiment is done may be no
>> more than asking him to perform a post-mortem examination: he may be
>> able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher
>> The plural of anecdote is not data. ~ Roger Brinner
>> The combination of some data and an aching desire for an answer does
>> not ensure that a reasonable answer can be extracted from a given body
>> of data. ~ John Tukey
>>
>>
>> 2015-08-24 13:00 GMT+02:00 Jhon Grey <butt_its_me op hotmail.com>:
>> > Hi!
>> > I am facing a problem in understanding the R-Code
>> > Suppose I have a dataset named- transact with its values like following:
>> >
>> >
>> >
>> >
>> >
>> > customer_ID
>> > shopping_pt
>> > record_type
>> >
>> >
>> > 10000000
>> > 1
>> > 0
>> >
>> >
>> > 10000000
>> > 2
>> > 0
>> >
>> >
>> > 10000000
>> > 3
>> > 0
>> >
>> >
>> > 10000000
>> > 4
>> > 0
>> >
>> >
>> > 10000000
>> > 5
>> > 0
>> >
>> >
>> > 10000000
>> > 6
>> > 0
>> >
>> >
>> > 10000000
>> > 7
>> > 0
>> >
>> >
>> > 10000000
>> > 8
>> > 0
>> >
>> >
>> > 10000000
>> > 9
>> > 1
>> >
>> >
>> > 10000005
>> > 1
>> > 0
>> >
>> >
>> > 10000005
>> > 2
>> > 0
>> >
>> >
>> > 10000005
>> > 3
>> > 0
>> >
>> >
>> > 10000005
>> > 4
>> > 0
>> >
>> >
>> > 10000005
>> > 5
>> > 0
>> >
>> >
>> > 10000005
>> > 6
>> > 1
>> >
>> >
>> > 10000007
>> > 1
>> > 0
>> >
>> >
>> > 10000007
>> > 2
>> > 0
>> >
>> >
>> > 10000007
>> > 3
>> > 0
>> >
>> >
>> > 10000007
>> > 4
>> > 0
>> >
>> > How does the following code work and the results of sub and id-
>> >
>> > id<-transact$record_type==1sub<-train[c(id[2:length(id)],FALSE),]id<-c(id[3:length(id)],FALSE,FALSE)
>> > sub2<-train[id,]
>> > Thanks in advance!
>> >
>> > [[alternative HTML version deleted]]
>> >
>> > ______________________________________________
>> > R-help op r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> > 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.