[R] Lattice, combine histogram and line graph

[David Winsemius]

On Jan 9, 2011, at 8:13 PM, Jim Burke wrote:

> Hello everyone,
>
> I have a simple histogram of gasoline prices going back a few years  
> that I want to insert a line graph of consumer price index (cpi)  
> over the histogram.  I have looked through the "Lattice" book by  
> Deepayan Sarkar but don't see anything there. How might this be  
> done? An example would be wonderful.
>
> Current code snippet follows. For example additional field to add as  
> a line graph would be a cpi calculation like "gas_data$regular *  
> (2010_cpi / gas_data$year )".
>
> xyplot( regular ~ as.Date(gas_data$dates,"%b %d, %Y") , data =  
> gas_data,
>       type = c("g", "h" ))

http://finzi.psych.upenn.edu/R/library/latticeExtra/html/doubleYScale.html

-- 

David Winsemius, MD
Heritage Laboratories
West Hartford, CT