Re: [R] xyplot auto.key issue

From: Mike Lawrence <Mike.Lawrence_at_dal.ca>
Date: Mon 01 Aug 2005 - 01:22:05 EST

Hi again,

Deepayan, I tried adding a "pch = c(1,2,3,4,5)" line in the auto key but the "zero-length 'pch'" error still occurs.

Sundar, I tried your code using key instead of auto.key, and after tweaking it to fit my design (i.e. from "x~y, groups = a" to "x~y | a, groups = b") it works perfectly! Thanks!

Here's the code that finally worked (that is, the modifications to Sundar's code, which might be clearer for others to follow than my own):

library(lattice)
set.seed(1)

z <- expand.grid(x=1:10, b = LETTERS[1:5], a = LETTERS[10:18]) z$y <- rnorm(nrow(z))

trellis.par.set(theme = col.whitebg())
par.line <- trellis.par.get("superpose.line") par.symb <- trellis.par.get("superpose.symbol") n <- seq(nlevels(z$b))

my.key <- list(

	space = "right",
	border = TRUE,
	cex.title = 1.2,
	title = "My Key",
	size = 7,
	lines = list(
		pch = par.symb$pch[n],
		lty = par.line$lty[n],
		col = par.line$col[n],
		type = "b"
	),
	text = list(
		levels(z$b)
	)

)

xyplot(

	y ~ x | a,
	data = z,
	groups = b,
	pch = par.symb$pch[n],
	type = "b",
	key = my.key

)

Quoting Sundar Dorai-Raj <sundar.dorai-raj@pdf.com>:

> Hi, Mike,
>
> Mike Lawrence wrote:
>> Hi Deepayan,
>>
>> Thanks for the reply, but when I enter the " type = "b" " code into
>> the auto.key
>> (see below) command I get the following message:
>>
>> Error in valid.pch(x$pch) : zero-length 'pch'
>>
>> Any suggestions?
>>
>
> Why not just ignore auto.key and use key? Personally, I use auto.key
> only when I want the defaults. If I want something more customized,
> then I use key. As in,
>
> library(lattice)
> set.seed(1)
> z <- expand.grid(x=1:10, g = LETTERS[1:5])
> z$y <- rnorm(nrow(z))
> trellis.par.set(theme = col.whitebg())
> par.line <- trellis.par.get("superpose.line")
> par.symb <- trellis.par.get("superpose.symbol")
> n <- seq(nlevels(z$g))
> my.key <- list(space = "right",
> border = TRUE,
> cex.title = 1.2,
> title = "My Key",
> size = 7,
> lines = list(pch = par.symb$pch[n],
> lty = par.line$lty[n],
> col = par.line$col[n],
> type = "b"),
> text = list(levels(z$g)))
> xyplot(y ~ x, z, groups = g,
> pch = par.symb$pch[n], type = "b",
> key = my.key)
>
>> xyplot(
>> #basic settings
>> bias ~ sample_size | measure,
>> data = bias,
>> groups = exp_tau,
>> type = "b",
>> pch = c(1,2,3,4,5),
>> xlab = "Sample Size",
>> ylab = "Bias (ms)",
>> #make strips transparent
>> strip = function(bg, ...) strip.default(bg = 'transparent', ...),
>> # tweak scales
>> scales=list(
>> x=list(
>> at = c(20, 40, 60),
>> tck = c(1,0),
>> alternating = F
>> ),
>> y=list(
>> at = c(-50, -25, 0, 25, 50),
>> tck = c(1,0),
>> alternating = F
>> )
>> ),
>> # tell key to match symbols to those used in the plot
>> par.settings = list(
>> superpose.symbol = list(
>> cex = .8,
>> pch = c(1,2,3,4,5)
>> )
>> ),
>> # key settings
>> auto.key = list (
>> type = "b",
>> lines = T,
>> border = T,
>> cex.title = 1.2,
>> title = "Expected Tau",
>> text = c("30 ms", "80 ms", "130 ms", "180 ms", "230 ms"),
>> space = "right"
>> )
>> )
>>
>>
>> Quoting Deepayan Sarkar <deepayan.sarkar@gmail.com>:
>>
>>
>>> On 7/30/05, Mike Lawrence <Mike.Lawrence@dal.ca> wrote:
>>>
>>>> Quick correction:
>>>>
>>>> The lines "lines = T," & "type = "b"" in the "par.settings" section should
>>>> not
>>>> be there. They are remnants of my previous (failed) attempts at
>>>> solving the
>>>> problem. Below is the correct code:
>>>>
>>>> xyplot(
>>>> #basic settings
>>>> bias ~ sample_size | measure,
>>>> data = bias,
>>>> groups = exp_tau,
>>>> type = "b",
>>>> pch = c(1,2,3,4,5),
>>>> #make strips transparent
>>>> strip = function(bg, ...) strip.default(bg = 'transparent', ...),
>>>> # tweak scales
>>>> scales=list(
>>>> x=list(
>>>> at = c(20, 40, 60),
>>>> tck = c(1,0),
>>>> alternating = F
>>>> ),
>>>> y=list(
>>>> at = c(-50, -25, 0, 25, 50),
>>>> tck = c(1,0),
>>>> alternating = F
>>>> )
>>>> ),
>>>> # tell key to match symbols to those used in the plot
>>>> par.settings = list(
>>>> superpose.symbol = list(
>>>> cex = .8,
>>>> pch = c(1,2,3,4,5)
>>>> )
>>>> ),
>>>> # key settings
>>>> auto.key = list (
>>>> lines = T,
>>>> size = 7,
>>>
>>> You seem to be missing a 'type="b"' somewhere here. The type="b"
>>> argument to xyplot is actually handled by the panel function. The key
>>> has type="l" by default (see under 'key' in ?xyplot) and has to be
>>> changed explicitly.
>>>
>>>
>>>> border = T,
>>>> cex.title = 1.2,
>>>> title = "Expected Tau",
>>>> text = c("30 ms", "80 ms", "130 ms", "180 ms", "230 ms"),
>>>> space = "right",
>>>> )
>>>> )
>>>>
>>>>
>>>>
>>>> Quoting Mike Lawrence <Mike.Lawrence@dal.ca>:
>>>>
>>>>
>>>>> Hi all,
>>>>>
>>>>> I'm having a problem with the auto.key function in xyplot. I hate to
>>>>> bother the
>>>>> list like this and I'm positive I must be missing something very simple,
>>>>
>>>> yet
>>>>
>>>>> I've spent the last day searching for a solution to no avail.
>>>>>
>>>>> Essentially, I want a key that contains entries in which the plot points
>>>>
>>>> are
>>>>
>>>>> superimposed on a line of the same color as the points, like this:
>>>>
>>>> o--o--o
>>>>
>>>>> Now, given the presence of the default "divide" command, I assume this is
>>>>> simple; indeed, I get the impression that this representation is
>>>>> supposed to be
>>>>> produced automatically. Yet I can't seem to get it to work!
>>>>>
>>>>> Now, I've incorporated various other tweaks to my xyplot function, so I'm
>>>>> wondering if these tweaks are somehow hindering my efforts. The function
>>>>
>>>> is
>>>>
>>>>> pasted below; I am making a 3x3 plot, each panel contains 5 lines and it
>>>>
>>>> is
>>>>
>>>>> these lines that I want represented in the key. See the comments for
>>>>> descriptions of the modifications.
>>>>>
>>>>> Any help would be greatly appreciated.
>>>>>
>>>>> Cheers,
>>>>>
>>>>> Mike
>>>>>
>>>>>
>>>>> xyplot(
>>>>> #basic settings
>>>>> bias ~ sample_size | measure,
>>>>> data = bias,
>>>>> groups = exp_tau,
>>>>> type = "b",
>>>>> pch = c(1,2,3,4,5),
>>>>> #make strips transparent
>>>>> strip = function(bg, ...) strip.default(bg = 'transparent', ...),
>>>>> # tweak scales
>>>>> scales=list(
>>>>> x=list(
>>>>> at = c(20, 40, 60),
>>>>> tck = c(1,0),
>>>>> alternating = F
>>>>> ),
>>>>> y=list(
>>>>> at = c(-50, -25, 0, 25, 50),
>>>>> tck = c(1,0),
>>>>> alternating = F
>>>>> )
>>>>> ),
>>>>> # tell key to match symbols to those used in the plot
>>>>> par.settings = list(
>>>>> superpose.symbol = list(
>>>>> cex = .8,
>>>>> pch = c(1,2,3,4,5)
>>>>> ),
>>>>> lines = T,
>>>>> type = "b"
>>>>> ),
>>>>> # key settings
>>>>> auto.key = list (
>>>>> lines = T,
>>>>> size = 7,
>>>>> border = T,
>>>>> cex.title = 1.2,
>>>>> title = "Expected Tau",
>>>>> text = c("30 ms", "80 ms", "130 ms", "180 ms", "230 ms"),
>>>>> space = "right",
>>>>> )
>>>>> )
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>>
>>>>> Mike Lawrence, BA(Hons)
>>>>> Research Assistant to Dr. Gail Eskes
>>>>> Dalhousie University & QEII Health Sciences Centre (Psychiatry)
>>>>>
>>>>> Mike.Lawrence@Dal.Ca
>>>>>
>>>>> "The road to Wisdom? Well, it's plain and simple to express:
>>>>> Err and err and err again, but less and less and less."
>>>>> - Piet Hein
>>>>>
>>>>> ______________________________________________
>>>>> R-help@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
>>>>
>>>>
>>>>
>>>> --
>>>>
>>>> Mike Lawrence, BA(Hons)
>>>> Research Assistant to Dr. Gail Eskes
>>>> Dalhousie University & QEII Health Sciences Centre (Psychiatry)
>>>>
>>>> Mike.Lawrence@Dal.Ca
>>>>
>>>> "The road to Wisdom? Well, it's plain and simple to express:
>>>> Err and err and err again, but less and less and less."
>>>> - Piet Hein
>>>>
>>>> ______________________________________________
>>>> R-help@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
>>>>
>>>
>>
>>
>>
>

-- 

Mike Lawrence, BA(Hons)
Research Assistant to Dr. Gail Eskes
Dalhousie University & QEII Health Sciences Centre (Psychiatry)

Mike.Lawrence@Dal.Ca

"The road to Wisdom? Well, it's plain and simple to express:
Err and err and err again, but less and less and less."
- Piet Hein

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Received on Mon Aug 01 01:28:58 2005

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