Hi
Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") : unable to connect to '
users.stat.umn.edu' on port
80.
>
Unable to read data.
>
> > interaction.plot(sex,rep(1,861),score,fun=mean,legend=F,main="profile
of
> > sex")
> Error: tapply(response, list(x.factor, trace.factor), fun) :
> arguments must have same length
However you are not telling us whole story. score shall be data frame and
length(data.frame) results in number of columns.
>From help page
x.factor a factor whose levels will form the x axis.
trace.factor another factor whose levels will form the traces.
response a numeric variable giving the response
your second variable to interaction plot is numeric - shall be factor
your third variable is probably data frame, shall be numeric.
It is advisable to give to functions values they expect. Some functions
can crunch unexpected data but the results can be misleading if not wrong.
Regards
Petr