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Lattice, combine histogram and line graph

5 messages · Jim Burke, David Winsemius, Joshua Wiley +1 more

Jim Burke
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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" ))

Thanks,
Jim Burke
David Winsemius
#
On Jan 9, 2011, at 8:13 PM, Jim Burke wrote:

            

      
      
      
    

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

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Joshua Wiley
    

    

      
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Hi Jim,

Some example data would help us.  I typically think of a histogram as
the frequency of values falling within a certain range (determined by
bins).  Since they are univariate plots, I'm not sure how you are
planning on adding a line graph to that.  If you just want bars of the
average gasoline price at different years, perhaps something along
these lines would work for you:

## Load required packages
require(lattice)
require(latticeExtra)

## Sample Data
dat <- data.frame(year = 1996:2010,
  x1 = rnorm(15, 3, .2), x2 = rnorm(15, 200, 1))

## Base xyplot (not a histogram) adding a layer with different y axis
xyplot(x1 ~ year, data = dat, type = "h") +
  as.layer(xyplot(x2 ~ year, data = dat, type = "l", col = "black"),
  y.same = FALSE)

## See
?xyplot
?as.layer
?hist # for info about histograms

HTH,

Josh

        
On Sun, Jan 9, 2011 at 5:13 PM, Jim Burke <j.burke at earthlink.net> wrote:

            

      
      
      
    

        

      
      
    

        

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Gabor Grothendieck
    

    

      
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On Sun, Jan 9, 2011 at 8:13 PM, Jim Burke <j.burke at earthlink.net> wrote:

            

      
      
      
    

        
xyplot.zoo in the zoo package has facilities for drawing multiple time
series using lattice graphics or in different panels.  The
documentation has many examples.

library(zoo)
library(lattice)

z1 <- zoo(1:6)
z2 <- z1^2
z <- cbind(z1, z2)
xyplot(z) # different panels
xyplot(z, screen = 1) # all on one panel

?xyplot.zoo
example(xyplot.zoo)
vignette(package = "zoo") # lists available vignettes

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Jim Burke
    

    

      
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Thanks Josh, Gabor, and David,

I appreciate your suggestions and the time you took to think about this. 
This was all most helpful. Gabor I will look at the zoo package soon. 
Sounds interesting.

Below is what worked for me from Josh to overlay a line graph on a 
histogram.


obj1 <- xyplot( regular ~ as.Date(gas_data$dates,"%b %d, %Y") , data = 
gas_data,
type = c("g", "h" ) )

obj2 <- xyplot( (gas_data$regular * (cpi_2010 / gas_data$cpi) ) ~ 
as.Date(gas_data$dates,"%b %d, %Y") , data = gas_data,
type = c( "l" ), col = "black" )

obj1 + as.layer(obj2, style = 2, axes = NULL, )


Have a great week,
Jim

        
Joshua Wiley wrote: