[R] weight

[Douglas Bates]

On 4/28/07, John Kane <jrkrideau at yahoo.ca> wrote:
> IIRC you have a yes/no smoking variable scored 1/2 ?
>
> It is possibly being read in as a factor not as an
> integer.
>
> try
>  class(df$smoking.variable)
> to see .

Good point.  In general I would recommend using

str(df)

to check on the class or storage type of all variables in a data frame
if you are getting unexpected results when manipulating it.  That
function is carefully written to provide a maximum of information in a
minimum of space.

>
>
> --- Natalie O'Toole <notoole at mtroyal.ca> wrote:
>
> > Hi,
> >
> > I'm getting an error message:
> >
> > Error in df[, 1:4] * df[, 5] : non-numeric argument
> > to binary operator
> > In addition: Warning message:
> > Incompatible methods ("Ops.data.frame",
> > "Ops.factor") for "*"
> >
> > here is my code:
> >
> >
> > ##reading in the file
> > happyguys<-read.table("c:/test4.dat", header=TRUE,
> > row.names=1)
> >
> > ##subset the file based on Select If
> >
> > test<-subset(happyguys, PROV==48 & GRADE == 7  &
> > Y_Q10A < 9)
> >
> > ##sorting the file
> >
> > mydata<-test
> > mydataSorted<-mydata[ order(mydata$Y_Q10A), ]
> > print(mydataSorted)
> >
> >
> > ##assigning  a different name to file
> >
> > happyguys<-mydataSorted
> >
> >
> > ##trying to weight my data
> >
> > data.frame<-happyguys
> > df<-data.frame
> > df1<-df[, 1:4] * df[, 5]
> >
> > ##getting error message here??
> >
> > Error in df[, 1:4] * df[, 5] : non-numeric argument
> > to binary operator
> > In addition: Warning message:
> > Incompatible methods ("Ops.data.frame",
> > "Ops.factor") for "*"
> >
> > Does anyone know what this error message means?
> >
> > I've been reviewing R code all day & getting more
> > familiar with it
> >
> > Thanks,
> >
> > Nat
> >
>
> >
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