[R] splitting data frame based on a criteria

[ctu at bigred.unl.edu]

Or ?gsummary


Quoting Moshe Olshansky <m_olshansky at yahoo.com>:

> Also check ?aggregate
>
>
> --- On Wed, 4/6/08, Ingmar Visser <i.visser at uva.nl> wrote:
>
>> From: Ingmar Visser <i.visser at uva.nl>
>> Subject: Re: [R] splitting data frame based on a criteria
>> To: "Marvin Lists" <marvin.lists at gmail.com>
>> Cc: r-help at r-project.org
>> Received: Wednesday, 4 June, 2008, 5:11 AM
>> ?by may be helpful here
>> eg if dat is your data.frame and yf is a factor (created
>> using ifelse)
>> use by(dat,yf,mean) to compute the means for each level of
>> yf
>> hth, Ingmar
>>
>> On Jun 3, 2008, at 8:37 PM, Marvin Lists wrote:
>>
>> > Hi,
>> > I have a data frame that I want to split into two
>> based on the
>> > values of a
>> > variable in it.
>> >
>> > The variable Y has numeric values ranging between 0
>> through 70. I
>> > want to
>> > plot the frequencies of another variable X in two
>> different cases:
>> > - When Y = 0 and
>> > - When Y > 0
>> >
>> > How does one go about doing this?
>> >
>> > In general, I want to do several analyses with this
>> data frame that
>> > are a
>> > variation of the above situation, i.e. they require
>> splitting the
>> > data into
>> > different age, gender etc. and then calculating
>> separate means,
>> > correlations
>> > and so on for the different groups into which the data
>> frame would
>> > split.
>> >
>> > I am struggling with the correct syntax for achieving
>> this.
>> >
>> > Reading through the documentation suggests that tapply
>> and split
>> > may be the
>> > functions to use for my purposes but the examples in
>> the
>> > documentations
>> > didn't help me understand how I could achieve
>> this.
>> >
>> > I would appreciate any suggestions and help.
>> >
>> > Thanks,
>> > Marvin
>> >
>> > 	[[alternative HTML version deleted]]
>> >
>> > ______________________________________________
>> > R-help at r-project.org mailing list
>> > 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.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> 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.
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.
>