# [R] how to use apply with a function created by ourselfs...?

ANA KOZOMARA magnolia at absolutok.net
Mon Apr 21 10:26:16 CEST 2003

```..hey thanks for the answer, both of you...
but :-(, I don't seem to have an answer to my problem...
I tried with what u suggested, but it doesn't work yet...
so I will precise it...
I have a data frame...
and I would like to apply the function "prediction" which acts on two
vectors
prediction(linear,ind),
to my data frame,I mean to all the rows of my data frame...
something like a function "Map" in Mathematica...
Shortly, I want to apply function "prediction" to a list of arguments, not
to a single argument...
I hope now it is more clear...
Thanks for the answers once more,
best regards,
ana
______________________________________________________________________
Original poruka
Od: Peter Dalgaard BSA <p.dalgaard at biostat.ku.dk>
Za: Spencer Graves <spencer.graves at pdf.com>
Tema: Re: [R] how to use apply with a function created by ourselfs...?
Primljena: 20 Apr 2003 22:31:52

Spencer Graves <spencer.graves at pdf.com> writes:

> By default, arithmetic in R is vectorized, with a scalar being a
> vector of length 1.
>
> Consider the following example:
>
> prediction <- function(a, b)
> {
> a+b
> }
>  > prediction(1:3, 4:6)
> [1] 5 7 9
>
> hope this helps, spencer graves

Not sure that was the question... If something else was meant, the

lapply(v,prediction,b=5)

or

do.call("prediction",as.list(v))

Rephrasing the question might help...

--
O__  ---- Peter Dalgaard             Blegdamsvej 3
c/ /'_ --- Dept. of Biostatistics     2200 Cph. N
(*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907

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