JiscMail Logo
Email discussion lists for the UK Education and Research communities

Help for ALLSTAT Archives


ALLSTAT Archives

ALLSTAT Archives


allstat@JISCMAIL.AC.UK


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

ALLSTAT Home

ALLSTAT Home

ALLSTAT  2005

ALLSTAT 2005

Options

Subscribe or Unsubscribe

Subscribe or Unsubscribe

Log In

Log In

Get Password

Get Password

Subject:

Feedback on html coding for sample mean

From:

Margaret MacDougall <[log in to unmask]>

Reply-To:

Margaret MacDougall <[log in to unmask]>

Date:

Fri, 28 Oct 2005 16:39:51 +0100

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (805 lines)

Dear all stat users

 

Earlier this month I sent the message below to allstat.  I received a variety of replies confirming that there is not a stand alone good html coding for creating the character for the sample mean which I wished. A big thank you to all who kindly replied.

 

 

Most of the suggestions pointed me to extension to html which could not be supported for universal use with my electronic system or were suggestive of a little overkill for one character.  I did try the suggestion made under reply 6 but the outcome looked a little out of place in the middle of the rest of my text.

 

In the end I used a simple draw facility to create the 'x-bar' symbol and was able to embed it in my text by capturing the image and pointing to it via a URL.  This was very easy to do and I was surprised to discover that the resultant character looked very pretty, much better than would have been possible had I used the Equation Editor in MS Word to create my image.

 

Necessity is the mother of invention!

 

 

 

 

Previous request of 13 October

=======================

 

I would be most grateful for suggestions on how best to code the conventional symbol for the sample mean (which I am taking to be a small x with a bar immediately above it) in the language of html.

 

At present, I am using the following approach:

 

<style type="text/css">
#overline {text-decoration: overline}
</style>
 <div id=overline>x,</div>

 

However, this tends to give a rather make-shift result, as the 'overline' tends to sit rather aloof from the x. Moreover, the character is forced onto a new line and therefore is not embedded in my sentence as wished.  

 

I have consulted several good html books and discovered that whilst listings of characters and codes are made for many characters including latin letters with circumflexes, the character I am after is not represented. 

 

I am learning html almost from scratch and expect that a more experienced user could offer some code which has worked for them in the past.  

 

An alternative approach would be to capture as an image the result of creating my desired character using an MS Word equation editor. However, this seems a little far fetched for just one character.

 

Thank you in advance for your suggestions.

 

Best wishes

 

Margaret

 

 

 

Reply 1

I don't think you can! I'm no expert on HTML either 

(and if there are any experts out there we'd love to be

 put right).


 


I've looked around a bit. There seems to be a consensus 

that you can't do much in the way of mathematical 

notation in standard HTML.


 


The nearest I've found -- which will only work in special


circumstances -- used a "proposed" extension to HTML called


"MATHML".


 


The syntax given there was


 


  <MATH><ABOVE>x</ABOVE></MATH>


 


with the caveat "Unfortunately most of the existing browsers do


not recognize the <MATH> tags, so you just get an x. The same


effect can be achieved in non<MATH> enabled browsers using a


<TABLE> construction; i.e.


 


  <TABLE><TH>_<BR>x</TH></TABLE>


 


which gives [display of x-bar on a separate line]"


 


See http://www2.sjsu.edu/faculty/watkins/html.htm


 


On my browsers (mozilla, firefox) the MATH did not work, and


the TABLE method put the x-bar on a new line, with the bar a


little too far above the x (just as described by Margaret).


 


I suspect, however, that the Opera browser does recognise MATH.


That's still no good, however, for people who don't use it!


 


The accented characters which are available in HTML at least


include those given as single entities in standard extended


ASCII character sets, such as iso-8859-1 which I'm using now,


and which your mail reader should render correctly, such as


 


         (only a selection) along with some stand-alone


accents.


 


These correspond to single ASCII codes and are not composed as


composite characters. Combinations of letter and accent which


are not amongst those available (e.g. above) in the character


set do not exist in HTML.


 


So, unless it's already a standard single character, you


cannot get it in HTML. In particular (apart from what may be


possible using <MATH>...</MATH>) you can't instruct HTML to


place an arbitrary mark as an "accent" to some other mark.


 


So, although the requisite stand-alone accent is available


in the iso-8859-1 set at position 175, the "macron" accent


(), and you can indeed get it displayed in HTML by entering


 


  


 


in your HTML, you can't as far as I can see instruct HTML


to display an "x" and then put a "" above it.


 


I agree that using Word + Equation Editor to get a bitmap


that you can import is overkill. And I'm personally no


admirer of the Equation Editor anyway. (Haven't we been


here before, and exactly on the "x-bar" topic? I recall that


pre-MedStats exchanges on this between Martin, John and me


about this were what first got us acquainted!)


 


Despite all this, I have two practical suggestions.


 


The first, for something as simple as x-bar, is simply to


write "x-bar". This will be readily understood, especially


if you initially explain that "x-bar stands for an x with a


bar over it; unfortunately this cannot be represented in


HTML so I'll just call it 'x-bar'".


 


The second is where you have occasion to use more than the


occasional mathematical symbol so that you need the reader


to see proper mathematical notation.


 


For web purposes, the ideal format for this is PDF. The


PDF display software Acrobat Reader is freely available


for most computer platforms from the Adobe website


 


  http://www.adobe.com


 


So you just put a link to a PDF file in your web page,


and if the person reading it has installed Acrobat Reader


then they can see it exactly as you intended, and also


print it out. Again, the can download and save the PDF


file, so can readily refer to it later. Nowadays I assume


that nearly everyone has Acrobat Reader available so I have


no qualms about sending them PDF files.


 


The main issue for this suggestion is creating the file


in PDF format in the first place.


 


You might use Word (with Equation Editor) to create a Word


document which displays the mathematics more or less as


you want it.


 


<ASIDE>People who want it really right, however, will use


software intended for formatting to precise typesetting


standards, such as TeX/LaTeX and groff which are both free,


and available for Windows and Unixoid systems, and commercial


products such as McKichan's "Scientific Word", which also


claims to be able to export the results directly to HTML


"with mathematics exported as graphics or as MathML."


 


For LaTeX and groff too there is the possibility to do it


this way, using embedded graphics for equations (e.g. a


program called LaTeX2HTML, which is another free program).


 


The advantage of using software which incorporates this


approach is that the user, while preparing the document,


simply types in whatever makes it look right on screen.


Then the ecporting to HTML is a single operation, and the


software takes care of embedding the graphics when required.


 


However, for the real thing the PDF route is the way to go.


There is no limit to the complexity of what can be represented


in PDF, and no limit to the precision with which it can be


represented. (Whether the software you used to create it can


match this, however, is another question).</ASIDE>


 


Suppose, then, that you have a suitable Word document.


I've heard (though not experienced) that recent versions of


Word can export to PDF (or there's a converter).


 


However, if not (or not in your case), then you can print


to file using one of the PostScript printer drivers


(e.g. Apple LaserPlus).


 


Now you have to convert the PostScript file to PDF. Adobe's


commercial Acrobat Distiller will do this (and is the "industry


standard" since both PostScript and PDF are Adobe's creations).


 


Free options include ghostscript (whose ps2pdf utility


does the job) and somewhat more refined programs which


are specialised for the job such as Frank Siegert's


PStill.


 


The resulting PDF file will display the mathematics as


well as (but probably no better than) it appeared in your


original Word document.


 


Hoping this helps -- and is not too discouraging!


 


 


Reply 2


 


Hi Margaret,


 


I think you might be unlucky with this one.


 


Here is an excellent webpage which covers some


html special characters:


 


http://www.xs4all.nl/~dimaroan/htl/characters.html#symbols


 


but if you want to generate some for yourself then open my


attachment and click the button. You will find 'mean a' at


number 257 and 'mean c' at 275, etc but only a few letters


are catered for.


 


I image one could devise a method using DHTML and the


div structure but then it would all get a bit too complicated.


 


 


Reply 3


 


HTML doesn't fit for this :(


The graphics approach (for the whole equation usually) is the best I've 


used


to get round it, but it's a poor solution. 


 


I should look to see if an of the Unicode fonts carry these symbols, 


but I


haven't yet and not yet worked out how to address them in html


 


 


Reply 4


 


The official list of characters available in html is at:


http://www.w3.org/TR/html4/sgml/entities.html#h-24.3


It seems that overline exists only as an independent character.


 


A natural solution is unicode which has combining diacriticals:


http://www.unicode.org/charts/PDF/U0300.pdf


 


Therefore, this should work:


 


<meta CONTENT="text/html CHARSET=UTF-8">


x <!-- should be x overline -->


 


but I find it is not supported on my browser.


 


Never use MS Word equation editor.  It produces very poor quality 


typesetting.


If you want to use an image, tex2im produces far better results and is 


much easier to use:


http://www.nought.de/tex2im.php


 


Reply 5


 


I faced the same problem a few years ago when I first began putting together the on-line stats text

 

http://faculty.vassar.edu/lowry/webtext.html

 

After trying every HTML device I could figure out for X-bar, I finally gave up and simply used Latin letter M -- which for students is probably a better mnemonic for Mean than X-bar anyway.  For Greek-letter notations I resorted to usinng small images of the ones I chiefly needed:  lower-case mu, lower- and upper-case sigma, and lower-case chi.  There are other ways of doing Greek-letter notations, though they tended to give different results on different platform-browser combinations.  The real trick was in rendering complex formulaic structures in HTML.  I finally figured out it could be done via carefully crafted borderless tables.  The result is a bit clunky, though it gets the job done well enough.

 


 


Reply 6


 


Use <span> instead of <div>.  To get the bar from being so high, use  


a capital X and then reduce the font size.


 


That would come out to:


 


>> <style type="text/css">


>> #overline {text-decoration: overline}


>> </style>


>>  <span id=overline>x,</span>


 


 


Reply 7


 


Hi,


 


Probably overkill for that particular query but when I need to write 


maths


in html, I use a very useful cgi called mimeTeX:


http://www.forkosh.com/mimetex.html


Once installed, you simply write the LaTeX code as you usually would, 


and


the picture is generated on the fly. You can also leave it in the cache


(better if the page receives a lot of hits).


 


It's fairly easy to install and doesn't require TeX. Just ask your 


sysadmin


if you're having difficulties. The page also refers to other solutions.



---------------------------------
To help you stay safe and secure online, we've developed the all new Yahoo! Security Centre.

		
---------------------------------
How much free photo storage do you get? Store your holiday snaps for FREE with Yahoo! Photos. Get Yahoo! Photos

Top of Message | Previous Page | Permalink

JiscMail Tools


RSS Feeds and Sharing


Advanced Options


Archives

December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
2006
2005
2004
2003
2002
2001
2000
1999
1998


JiscMail is a Jisc service.

View our service policies at https://www.jiscmail.ac.uk/policyandsecurity/ and Jisc's privacy policy at https://www.jisc.ac.uk/website/privacy-notice

Secured by F-Secure Anti-Virus CataList Email List Search Powered by the LISTSERV Email List Manager