From: A. Mani <a_mani_sc_gs_at_vsnl.net>

Date: Sat 20 Aug 2005 - 07:56:12 EST

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Aug 20 07:40:43 2005

Date: Sat 20 Aug 2005 - 07:56:12 EST

On Friday 19 August 2005 11:54, Sean O'Riordain wrote:

*> Hi,
*

> I'm not sure what you actually want from your email (following the

*> posting guide is a good way of helping you explain things to the rest
**> of us in a way we understand - it might even answer your question!
**>
**> I'm only a beginner at R so no doubt one of our expert colleagues will
**> help me...
**>
**> > fred <- data.frame()
**> > fred <- edit(fred)
**> > fred
**>
**> A B C D E
**> 1 1 2 X Y 1
**> 2 2 3 G L 1
**> 3 3 1 G L 5
**>
**> > fred[,3]
**>
**> [1] X G G
**> Levels: G X
**>
**> > fred[fred[,3]=="G",]
**>
**> A B C D E
**> 2 2 3 G L 1
**> 3 3 1 G L 5
**>
**> so at this point I can create a new dataframe with column 3 (C) ==
**> "G"; either explicitly or implicitly...
**>
**> and if I want to calculate the sum() of column E, then I just say
**> something like...
**>
**> > sum(fred[fred[,3]=="G",][,5])
**>
**> [1] 6
**>
**>
**> now naturally being a bit clueless at manipulating stuff in R, I
**> didn't know how to do this before I started... and you guys only get
**> to see the lines that I typed in and got a "successful" result...
**>
**> according to section 6 of the "Introduction to R" manual which comes
**> with R, I could also have said
**>
**> > sum(fred[fred$C=="G",]$E)
**>
**> [1] 6
**>
**> Hmmm.... I wonder would it be reasonable to put an example of this
**> type into section 2.7 of the "Introduction to R"?
**>
**>
**> cheers!
**> Sean
**>
**> On 18/08/05, A. Mani <a_mani_sc_gs@vsnl.net> wrote:
**> > Hello,
**> > I want to avoid loops in the following situation. There is a
**> > 5-col dataframe with col headers alone. two of the columns are
**> > non-numeric. The problem is to calculate statistics(scores) for each
**> > element of one column. The functions depend on matching in the other
**> > non-numeric column.
**> >
**> > A B C E F
**> > 1 2 X Y 1
**> > 2 3 G L 1
**> > 3 1 G L 5
**> > and so on ...30000+ entries.
**> >
**> > I need scores for col E entries which depend on conditional implications.
**> >
**> >
**> > Thanks,
**> >
*

Hello,

Sorry about the incomplete problem. Here is a better version for the
problem: (the measure is not simple)

The data frame is like

col1 col2 col3 col4 col5 <num> <nonum> <nonum> <num> <num> A B C E FThere are repeated strings in col3, col2. Problem : Calculate Measure(Ci) = [No. of repeats of Ci *100] + [If (Bi, Ci) is same as (Bj, Cj) and 6>= Ej - Ei >=3 then add 100 else 10] .

Actually it is to stretched further by adding similar blocks.

How do we use *apply or

something else in the situation ?

In prolog it is extremely easy, but here it is not quite...

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Aug 20 07:40:43 2005

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