R help - Feb 2005 - Lattice --reference line in panels does not come up

R-help,

I am quite new to lattice.
I am plotting something in which I want some reference lines.
I do the foolowing :

library ( lattice )
reference.line <- trellis.par.get ( "reference.line" ) 
reference.line$lty <- 2    ## not working with any of the
reference.line components
# reference.line$col <- "red" 
trellis.par.set("reference.line", reference.line)
xyplot ( number ~ cm | year , data = lgda., type = "l", col =
"black" ,
ylab = "Number", xlab = "Length (cm) ") ## the actual plot

The result is without reference lines.

What am I doing wrong?


Thanks in advance

Luis Ridao Cruz wrote:
> R-help,
> 
> I am quite new to lattice.
> I am plotting something in which I want some reference lines.
> I do the foolowing :
> 
> library ( lattice )
> reference.line <- trellis.par.get ( "reference.line" ) 
> reference.line$lty <- 2    ## not working with any of the
> reference.line components
> # reference.line$col <- "red" 
> trellis.par.set("reference.line", reference.line)
> xyplot ( number ~ cm | year , data = lgda., type = "l", col =
"black" ,
> ylab = "Number", xlab = "Length (cm) ") ## the actual
plot
> 
> The result is without reference lines.
> 
> What am I doing wrong?

You have forgotten to specify panel.grid() in your call, which is the 
only function accepting reference line settings, AFAIK. The following 
should do the trick:

  xyplot(.....,
    panel = function(x, y, ...){
      panel.xyplot(x, y, ...)
      panel.grid()
    }
  )



Uwe Ligges



> 
> Thanks in advance
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html

Thank you Uwe,

It worked !

Luis
>>> Uwe Ligges <ligges at statistik.uni-dortmund.de> 16/02/2005
13:21:27
>>>
Luis Ridao Cruz wrote:
> R-help,
> 
> I am quite new to lattice.
> I am plotting something in which I want some reference lines.
> I do the foolowing :
> 
> library ( lattice )
> reference.line <- trellis.par.get ( "reference.line" ) 
> reference.line$lty <- 2    ## not working with any of the
> reference.line components
> # reference.line$col <- "red" 
> trellis.par.set("reference.line", reference.line)
> xyplot ( number ~ cm | year , data = lgda., type = "l", col =
"black"
,
> ylab = "Number", xlab = "Length (cm) ") ## the actual
plot
> 
> The result is without reference lines.
> 
> What am I doing wrong?

You have forgotten to specify panel.grid() in your call, which is the 
only function accepting reference line settings, AFAIK. The following 
should do the trick:

  xyplot(.....,
    panel = function(x, y, ...){
      panel.xyplot(x, y, ...)
      panel.grid()
    }
  )



Uwe Ligges



> 
> Thanks in advance
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help 
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html

Uwe Ligges wrote:
> Luis Ridao Cruz wrote:
> 
>> R-help,
>>
>> I am quite new to lattice.
>> I am plotting something in which I want some reference lines.
>> I do the foolowing :
>>
>> library ( lattice )
>> reference.line <- trellis.par.get ( "reference.line" ) 
>> reference.line$lty <- 2    ## not working with any of the
>> reference.line components
>> # reference.line$col <- "red"
trellis.par.set("reference.line",
>> reference.line)
>> xyplot ( number ~ cm | year , data = lgda., type = "l", col =
"black" ,
>> ylab = "Number", xlab = "Length (cm) ") ## the
actual plot
>>
>> The result is without reference lines.
>>
>> What am I doing wrong?
> 
> 
> 
> You have forgotten to specify panel.grid() in your call, which is the 
> only function accepting reference line settings, AFAIK. The following 
> should do the trick:
> 
>  xyplot(.....,
>    panel = function(x, y, ...){
>      panel.xyplot(x, y, ...)
>      panel.grid()
>    }
>  )
Or, in recent versions of the lattice package,

  xyplot(..., type = c("g", "p"))