[R] display double dot over character in plotmath?

[Duncan Murdoch]

On 15/05/2017 8:18 AM, Olivier Crouzet wrote:
> Hi,
>
> The following simple solution gives appropriate results in base R (and
> should work with any base character):
>
> plot(rnorm(100), rnorm(100), main = expression(paste(omega, "\u0308")))

It doesn't work for me on Mac OS or Windows 10 in the default device or 
pdf().  The trouble with Unicode solutions is that R graphics devices 
aren't required to support it.

Duncan Murdoch

>
> In your ggplot example, something like:
>
> ggplot(data, aes(x=X)) + geom_line(aes(y = Z), size=0.43) + xlab
> (expression(atop(top, bold(Age~paste(omega,"\u0308")))))
>
> seems to produce what you need (AFAICT).
>
> Note that, contrary to Robert's examples, one has to put
> the corresponding diacritic AFTER the base character in unicode
> conventions. Also, one needs to put the omega and "\u0308" within a
> paste() function in order to concatenate them correctly and to reach a
> state in which they "combine" together.
>
> Inserting this into your own code, the characters are not bold though
> and I'm not sure what the solution would be. This may be an issue with
> the font that is used. Also note that in order to export the graph to
> pdf, you'd need to use cairo_pdf() in order to get the character
> displayed correctly.
>
> Olivier.
>
>
> On Sun, 14 May 2017 10:43:40 -0500
> Ranjan Maitra <maitra at email.com> wrote:
>
>> Thanks, Duncan!
>>
>> This works for the particular case and is, to my mind, a great
>> solution!
>>
>> However, I was wondering: is it possible to use these double dots
>> with another character, such as omega?
>>
>> I apologize for changing the question somewhat, but I did not realize
>> earlier that there were separate codes for putting double dots over
>> different letters and I thought that figuring out the simpler
>> question would be enough for me to figure out the next step.
>>
>> Thanks again!
>>
>> Best wishes,
>> Ranjan
>>
>>
>>
>> On Sun, 14 May 2017 23:57:50 +1000 Duncan Mackay
>> <dulcalma at bigpond.com> wrote:
>>
>>> Hi
>>>
>>> I just had to do something similar in windows with \"{u}. Try
>>> Unicode symbol
>>> - see ?plotmath
>>>
>>> ggplot(data, aes(x=X)) + geom_line(aes(y = Z), size=0.43) +
>>> xlab(expression(atop(top,bold(Age~"\u00e4"))))
>>>
>>> Regards
>>>
>>> Duncan
>>>
>>> Duncan Mackay
>>> Department of Agronomy and Soil Science
>>> University of New England
>>> Armidale NSW 2351
>>> Email: home: mackay at northnet.com.au
>>>
>>> -----Original Message-----
>>> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of
>>> Ranjan Maitra
>>> Sent: Saturday, 13 May 2017 22:48
>>> To: r-help at stat.math.ethz.ch
>>> Subject: Re: [R] display double dot over character in plotmath?
>>>
>>> On Fri, 12 May 2017 23:39:14 -0700 Daniel Nordlund
>>> <djnordlund at gmail.com> wrote:
>>>
>>>> On 5/12/17 4:55 PM, Ranjan Maitra wrote:
>>>>> Hi,
>>>>>
>>>>> Is it possible to display double dot (umlaut) over a character
>>>>> such as
>>> would be possible using \ddot x in LaTeX? I can do this using
>>> tikzDevice but I wanted something simpler to point to.
>>>>>
>>>>> Here is an example of what I would like to do, but it is not
>>>>> quite
>>> there:
>>>>>
>>>>> require(ggplot2)
>>>>> data<-as.data.frame(c("a","b","c","a","b","c"))
>>>>> colnames(data)<-"Y"
>>>>> data$X<-c(1:6)
>>>>> data$Z<-c(1,2,3,1,2,3)
>>>>>
>>>>> ggplot(data, aes(x=X)) + geom_line(aes(y = Z), size=0.43) +
>>> xlab(expression(atop(top,bold(Age~"à"))))
>>>>>
>>>>> I would like to put in a double dot over the "a" in the x-axis
>>>>> instead
>>> of "`".
>>>>>
>>>>> Many thanks for any suggestions and best wishes,
>>>>> Ranjan
>>>>>
>>>>
>>>> You haven't told what OS you are using, but with Windows OS, you
>>>> can get the 'ä' by making sure the NUMLOCK key is on, hold down
>>>> the alt key and press 0228 on the numeric keypad.
>>>>
>>>>
>>>
>>> I am sorry, I use a linux operating system. I use Fedora 25 but the
>>> student I wanted to show this uses Ubuntu, though I don't know if
>>> the distribution matters.
>>>
>>> Thanks again for your help, and best wishes,
>>> Ranjan
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html and provide commented,
>>> minimal, self-contained, reproducible code.
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html and provide commented,
>>> minimal, self-contained, reproducible code.
>>>
>>
>>
>> --
>> Important Notice: This mailbox is ignored: e-mails are set to be
>> deleted on receipt. Please respond to the mailing list if
>> appropriate. For those needing to send personal or professional
>> e-mail, please use appropriate addresses.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html and provide commented,
>> minimal, self-contained, reproducible code.
>
>