[R] overlap different line in a xyplot (lattice)

[Peter Ehlers]

On 2010-12-11 16:47, Felix Andrews wrote:
> On 12 December 2010 00:08, Peter Ehlers<ehlers at ucalgary.ca>  wrote:

[...snip...]

>> The idea is the same: you need to get your data
>> into "long" format with a grouping variable and
>> then use the 'groups' argument to xyplot.
>> Here's fake data frame (you should have provided one):
>>
>>   DF<- data.frame(y1 = rnorm(30),
>>                   y2 = rnorm(30) + 2,
>>                   x  = rep(1:10, 3),
>>                sites = gl(3, 10, lab=LETTERS[1:3]))
>>
>> ## Use the reshape2 package to melt the data:
>> ## (or use reshape() in base R)
>>   require(reshape2)
>>   DF1<- melt(DF, measure.vars = c('y1', 'y2'),
>>              variable.name = 'grp', value.name = 'y')
>>
>> ## and plot:
>>   require(lattice)
>>   p<- xyplot( y ~ x | sites, data = DF1, groups = grp,
>>              col = c("red", "blue"), type = "b")
>>   print(p)
>>
>> Peter Ehlers
>
>
> By the way, in this particular case there is a shortcut which does the
> reshaping internally:
>
> xyplot(y1 + y2 ~ x | sites, DF, type = "b")

Right; thanks for the reminder, Felix. I keep forgetting
about that mainly because I almost always need 'long' data.

Peter Ehlers

[...snip...]