**From:** ANA KOZOMARA (*magnolia@absolutok.net*)

**Date:** Mon 21 Apr 2003 - 19:43:19 EST

**Next message:**Luis Silva: "Re: [R] loop"**Previous message:**Peter Dalgaard BSA: "Re: [R] how to use apply with a function created by ourselfs...?"**Maybe in reply to:**Peter Dalgaard BSA: "Re: [R] how to use apply with a function created by ourselfs...?"

Message-id: <000e92043091543SILJA@silja.absolutok.com>

hey thanks a lot...

finally I decided to write my own fonction which will do it...

I was completely lost with rbind, mode="list"...

I find slightely weird the R-kind-of-thinking...:)))

Anyway, i'm trying to acomplish my project in R and not c spirit,

so i'll try what u suggests,

..hey, thanks a lot again...

______________________________________________________________________

Original poruka

Od: Peter Dalgaard BSA <p.dalgaard@biostat.ku.dk>

Za: ANA KOZOMARA <magnolia@absolutok.net>

Tema: Re: [R] how to use apply with a function created by ourselfs...?

Primljena: 21 Apr 2003 11:27:48

"ANA KOZOMARA" <magnolia@absolutok.net> writes:

*> ..hey thanks for the answer, both of you...
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*> but :-(, I don't seem to have an answer to my problem...
*

*> I tried with what u suggested, but it doesn't work yet...
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*> so I will precise it...
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*> I have a data frame...
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*> and I would like to apply the function "prediction" which acts on two
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*> vectors
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*> prediction(linear,ind),
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*> to my data frame,I mean to all the rows of my data frame...
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*> something like a function "Map" in Mathematica...
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*> Shortly, I want to apply function "prediction" to a list of arguments,
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not

*> to a single argument...
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*> I hope now it is more clear...
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*> Thanks for the answers once more,
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*> best regards,
*

*> ana
*

It depends on your prediction function. The best thing is to arrange

that it vectorizes over its arguments, as Spencer Graves suggested.

Then it's just

prediction(df[,1],df[,2])

or, if you want something that works for more than two rows,

do.call("prediction", df)

if your prediction() does not vectorize (i.e. a and b has to be

scalars), you can do two things:

pr.row <- function(row) do.call("prediction",row)

apply(df, 1, pr.row)

or create a vectorized prediction(), as in

pr.vec <- function(a,b)

sapply(seq(along=a),function(i)prediction(a[i],b[i]))

-- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk) FAX: (+45) 35327907______________________________________________ R-help@stat.math.ethz.ch mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help

**Next message:**Luis Silva: "Re: [R] loop"**Previous message:**Peter Dalgaard BSA: "Re: [R] how to use apply with a function created by ourselfs...?"**Maybe in reply to:**Peter Dalgaard BSA: "Re: [R] how to use apply with a function created by ourselfs...?"

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