Hi Robin:
I think you can avoid the loops doing this:
my.df<-data.frame(d.o.w=sample(c("mon","sat","sun"), 20, replace=T),
admissions=rnorm(20))
weight <- c(1,1,1,1,1,1.21,1.22)
names(weight) <- c("mon","tue","wed","thu","fri","sat","sun")
my.df$NewAdm <- my.df$admissions * weight[as.character(my.df$d.o.w)]
my.df
Gabriela
----- Original Message -----
From: "Robin Williams" <[EMAIL PROTECTED]>
To: <r-help@r-project.org>
Sent: Wednesday, July 23, 2008 12:44 PM
Subject: [R] Using if, else statements
Hi all,
Again I have searched the net and so on, without finding an answer to this
surely simple problem. A short bit of code would be appreciated.
I have a object named `data' with the following column headings.
Date, maxitemp, minitemp, admissions, d.o.w.
Where d.o.w. is day of the week, written "Sun" "Mon" etc.
I just need to scale the Monday admissions by 0.91, the Saturday
admissions by 1.21 and the Sunday admissions by 1.22. So basically what I
want is:
If d.o.w. == "Sat"
Multiply Sat admissions by 1.21.
(Now do I need an else statement here, or can I just do another)
If d.o.w. == "Sun"
Multiply "Sun" admissions by 1.22
(and finally)
If d.o.w. == "Mon"
Multiply Monday admissions by 0.91.
Else do nothing.
I assume in my code I need to specify that I am using the data.frame
`data', so do I need to write things like
If(data[d.o.w.]=="Mon")
I would then like to round the new admissions to integers (I assume I
just
use round(data$admissions)), and output the new data to another csv file.
I could of course do this in excel but I will need to extend this type of
idea in the future so I would like to master it in R.
Many thanks for any help/code.
Robin Williams.
[[alternative HTML version deleted]]
______________________________________________
R-help@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.
___________________________________________________________________________
Aviso:
=====
El contenido del presente e-mail y sus posibles adjuntos pertenecen al INTA y pueden contener información confidencial. Si usted no es el destinatario original de este mensaje y por este medio pudo acceder a dicha información, por favor solicitamos contactar al remitente y eliminar el mensaje de inmediato. Se encuentra prohibida la divulgación, copia, distribución o cualquier otro uso de la información contenida en el presente e-mail por parte de personas distintas al destinatario.
This e-mail contents and its possible attachments belong to INTA and may
contain confidential information. If this message was not originally addressed
to you, but you have accessed to such information by this means, please contact
the sender and eliminate this message immediately. Circulation, copy,
distribution, or any other use of the information contained in this e-mail is
not allowed on part of those different from the addressee.
Antes de imprimir este mensaje, asegúrese de que sea necesario. Proteger el
medio ambiente está también en su mano.
______________________________________________
R-help@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.
