[R] strip levels

[Christine Lee]

To whom it may help,

I am new to R.

I have been tring to have a lattice plot in two strip levels: 4 stations in 2 years.  

I type in:

histogram(~Raw.no10$Width|Raw.no10$Station*Raw.no10$Year, data=Raw.no10, layout=c(4,2),nin=30,xlab="Prosomal Width (mm)", strip=strip.custom(bg='white'),ylab="Frequencies",tick=-1,col='grey',as.table=TRUE)

The second level, i.e. Year, showed as "Raw.no10$Year" in the each of the lattice plot, instead of its respective year, such as "2002" and "2014".

I changed to the following programme language, therefore:

histogram(~Raw.no10$Width|Raw.no10$Station*Raw.no10$Year, data=Raw.no10, layout=c(4,2),nin=30,xlab="Prosomal Width (mm)", strip=strip.custom(bg='white',var.name=c("2002","2014")),ylab="Frequencies",tick=-1,col='grey',as.table=TRUE) 

in order to specify the variable names of the strip.

Instead of showing "Raw.no10$Year", each of the lattice plot states "2014"!  They should have 4 plots showing "2002" and another 4 showing "2014".

Could any one help indicating what has gone wrong?

I am really helpless and frustrated now.  T_T

Regards,
Christine