[Rd] `mgp[1:3]' are of differing sign (PR#14130)

[p.dalgaard at biostat.ku.dk]

Peter Ehlers wrote:
> 
> cornell.p.gonschior at iem.fh-friedberg.de wrote:
>> Full_Name: Cornell Gonschior
>> Version: 2.10.0
>> OS: Linux
>> Submission from: (NULL) (212.201.28.40)
>>
>>
>> Hi,
>>
>> in the introduction to R, you can find the following sentence in the 
>> par()
>> chapter:
>> "Use tck=0.01 and mgp=c(1,-1.5,0) for internal tick marks."
>> I thought that's nice, because I wanted to have tick marks and tick 
>> labels
>> inside and the axis title outside.
>>
>> But:
>>> plot(z, las=1, tck=0.01, mgp=c(1,-1.5,0))
>> Warnmeldungen:
>> 1: In plot.window(...) : `mgp[1:3]' are of differing sign
>> 2: In plot.xy(xy, type, ...) : `mgp[1:3]' are of differing sign
>> 3: In axis(side = side, at = at, labels = labels, ...) :
>>   `mgp[1:3]' are of differing sign
>> 4: In axis(side = side, at = at, labels = labels, ...) :
>>   `mgp[1:3]' are of differing sign
>> 5: In box(...) : `mgp[1:3]' are of differing sign
>> 6: In title(...) : `mgp[1:3]' are of differing sign
>>
>>> par(las=1, tck=0.01, mgp=c(1,-1,0))
>> Warnmeldung:
>> In par(las = 1, tck = 0.01, mgp = c(1, -1, 0)) :
>>   `mgp[1:3]' are of differing sign
>>
>> Was there a recent change, couldn't find anything useful searching the 
>> web.
>>
>> Regards,
>> Cornell
> 
> Well, it's only a warning, making you aware of a possibly
> unintended par setting. Warnings are good things but if you
> don't want to see them, they can be suppressed.
> 
> Certainly not a bug.

Hmm, then again, I tend to agree with Cornell that there are a bit too 
many cases where mgp[1:3]' would sensibly have differing sign, compared 
to cases where it is a mistake. In addition to internal tick marks and 
labels, there are also cases where the whole axis is shifted into the 
plot area. I'd more likely use axis(pos=...) for that, but still.

-- 
    O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
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