[R] multiple lty on same panel in xyplot

[Deepayan Sarkar]

On Wed, Aug 5, 2009 at 2:24 PM, Jacob Wegelin<jacob.wegelin at gmail.com> wrote:
> On Wed, 5 Aug 2009, Deepayan Sarkar wrote:
>
>> On 8/5/09, Jacob Wegelin <jacob.wegelin at gmail.com> wrote:
>>> I would like to use lattice graphics to plot multiple functions (or
> groups
>>>  or subpopulations) on the same plot region, using different line types
> "lty"
>>>  or colors "col" to distinguish the functions (or groups).
>>>
>>>  In traditional graphics, this seems straightforward: First plot all the
> data
>>>  using 'type="n"', and subsequently execute a series of "points" or
> "lines"
>>>  commands, one for each different group or function.
>>>
>>>  What is the elegant way to do this using xyplot?
>>>
>>>  To make this concrete, consider the following toy example:
>>>
>>>  k<- 10
>>>  x<- (1:k)/3
>>>  yM<-6 + x^2
>>>  yF<-12 + x^(1.5)
>>>  xNA<-x[length(x)]
>>>
>>>  # Insertion of NA row is necessary to prevent a meaningless line
>>>  # from being drawn from the females to the males across the entire plot.
>>>
>>>  DAT<-data.frame(
>>>  x=c(x, xNA, x)
>>>  ,
>>>  y=c(yF, NA, yM)
>>>  ,
>>>  sex=c( rep(0, k ), 0,  rep(1, k))
>>>  )
>>
>> It's much simpler in lattice, and you don't need to play such tricks.
> Option 1:
>>
>> xyplot(yM + yF ~ x, type = "l", auto.key = list(points = FALSE, lines =
> TRUE))
>>
>> and if you want to control lty etc:
>>
>> xyplot(yM + yF ~ x, type = "l", auto.key = list(points = FALSE, lines =
> TRUE),
>>       par.settings = simpleTheme(lty = c(2, 3)))
>>
>>
>> Option 2 (a bit more work, but less mysterious under the hood):
>>
>> DAT<-
>>    data.frame(x = c(x, x), y=c(yF, yM),
>>               sex= rep(c("Female", "Male"), each = length(x)))
>>
>> xyplot(y ~ x, data = DAT, groups = sex, type = "l")
>
> Dear Bill and Deepayan,
>
> Thanks. This is helpful. Where can one find a thorough documentation of all
> these features like par.settings, simpleTheme, the options for where to
> place the legend or "key", auto.key, the different locations besides "top"
> where one can place the "auto.key", etc.?  I don't think this is all clearly
> laid out in the R help files or latticeLab.pdf.

(Almost) everything is mentioned in the help pages (?Lattice is a good
place to start). Of course finding the thing you are looking for is
another matter. The book does try to present things more
systematically.

> But using your hints I found that the following worked:
>
> xyplot(
> y ~ x
> , groups= ~ sex
> , type="l"
> , auto.key = list(columns=2, points = FALSE, lines = TRUE)
> , par.settings = simpleTheme(lty = c(1, 2), col="black")
> , data=DAT
> )
>
> Now, how would I use lattice tools to plot males with a line and females
> with points--and still get an informative autokey?

xyplot(yM + yF ~ x, type = c("l", "p"), distribute.type = TRUE,
       par.settings = simpleTheme(lty = c(1, 2), col="black"),
       auto.key = list(points = FALSE, lines = TRUE, type = c("l", "p")))


...but this is pretty much impossible to figure out for a beginner.
On the other hand, reading the documentation carefully should lead you
to the following, which is almost there:


pset <- simpleTheme(lty = c(1, 2), col="black")

xyplot(yM + yF ~ x,
       panel = panel.superpose,
       type = c("l", "p"),
       distribute.type = TRUE,
       par.settings = pset,
       key = list(text = list(c("male", "female")),
                  lines = Rows(pset$superpose.line, 1:2),
                  pch = 1,
                  type = c("l", "p")))

-Deepayan