Talk to me

Math tags

I noticed you removed the math tags from the Munchausen task. Why? Were they not rendering correctly? Fwend (talk) 12:15, 24 September 2016 (UTC)

Yes, They rendered the text invisible on Internet explorer. :-( What good are they anyway? --Walterpachl (talk) 13:15, 24 September 2016 (UTC)
What good are they? They render formulas much better. Fwend (talk) 14:17, 24 September 2016 (UTC)
The MediaWiki processing of <math> tags can go wrong if they enclose unexpected redundant space. As a result, ill-formed HTML is generated which prevents the display of the graphic file for the formula on most browsers, though a minority, like Firefox, can still use an alternative route, if the right fonts are installed, by locally processing MathML.
On the whole, you should find that you don't need to entirely remove the <math> tag - eliminating redundant space between the tags, particularly just after the opening tag, and just before the closing tag, should usually be enough, though there are some other special space patterns which also choke the MediaWiki's translation of <math> tags into HTML Hout (talk) 13:27, 24 September 2016 (UTC)
The most important thing is that if anyone uses or edits <math> tags, they must be careful to test them on both kinds of browsers, i.e. for example, on one of the browsers like Chrome, Safari, IE (the majority - which use the graphic file), and on one of the minority, like Firefox, which can locally process MathML to display a formula, as long as the right fonts are installed. Hout (talk) 13:27, 24 September 2016 (UTC)
For a list of tasks descriptions with formulae which have accidentally been made invisible to most browsers by <math> tag editing in the last six months, see:
I know about the redundant space but mine didn't have any, as far as I can see: <math>3435 = 3^3+4^4+3^3+5^5</math>. I just tried it with Edge and it does indeed not render, which is strange because Edge does render the Wikipedia math tags. Fwend (talk) 14:17, 24 September 2016 (UTC)
Is that expression well-formed in TeX ? I think that the MediaWiki's generation of a graphic file (with its wrapping HTML) for use by the majority of browsers may choke unless it manages to parse the expression as TeX. Hout (talk) 14:24, 24 September 2016 (UTC)
If I copy and paste the math tags above to wikipedia, using exactly the same Edge browser, it renders just fine (in the preview). It looks like this tag only fails at Rosetta Code. Fwend (talk) 15:03, 24 September 2016 (UTC)
If you inspect the HTML generated, you will find that the Rosetta installation of MediaWiki is creating the graphic file OK, but dropping a semi-colon between two attributes, so that the browser just finds ill-formed HTML and skips it.
Perhaps Wikipedia has installed a later build ? Tho even they have related problems – only yesterday I restored the lost visibility of one of the first three formulae on the Wiki page on Symmetric Difference, by pruning extraneous space out of its <math> tag ... Hout (talk) 15:07, 24 September 2016 (UTC)
Just checked – Wikipedia is using a slightly later build MediaWiki 1.28.0-wmf.20 (vs Rosetta's MediaWiki 1.26.2) so an upgrade might reduce the fragility of the <math> tag processing – though not (to judge from yesterday's invisible Wikipedia formulae) entirely eliminate it.
Cosmetic editing will still need to involve checking in both kinds of browsers Hout (talk) 15:33, 24 September 2016 (UTC)
See Hout (talk) 14:27, 24 September 2016 (UTC) Hout (talk) 14:30, 24 September 2016 (UTC)

Edit oddity

Hi Walterpachl, it seems you had problems with an edit here, but the data was recovered. --Paddy3118 15:32, 5 July 2012 (UTC)

I had some from my country home desk top
I'm not aware of any today!
--Walterpachl 15:55, 5 July 2012 (UTC)

Hi, If you follow the link you should see that you cut the "malformed numbers" section from that page. --Paddy3118 19:20, 5 July 2012 (UTC)

Broken Link

Hi Walter, When I follow the link you posted on your user page: I get the following error message:

Diese Seite existiert nicht und sie kann auch nicht erstellt werden, da die darunterliegende Kategorie Infos_zum_AF/Editorial_Board gesperrt ist!

(English translation courtesy Google Chrome: This page does not exist and they can not be created because the underlying category Infos_zum_AF / Editorial_Board is locked!) --Alansam 20:23, 10 July 2012 (UTC)

Thanks for telling me. I think I've fixed it now! --Walterpachl 17:45, 13 July 2012 (UTC)


Are you the Walter that asked the question on my Wikipedia user page? Because, if so, I've answered it on my Wikipedia user talk page. (If it wasn't you, then sorry, disregard.) -- Erik Siers 01:20, 21 July 2012 (UTC)

Discussion moved from task page

Hi, I just moved your discussion from the task page. It may need cleanup. We don't normally have such discussions on the task page. --Paddy3118 (talk) 10:05, 8 June 2013 (UTC)

Thank you, I was going to ask GS to do that. Can you voice your opinion about the worthiness of (restricted) simpler solutions? --Walterpachl (talk) 10:13, 8 June 2013 (UTC)
Just my opinion: if there is an answer there already that gets flagged as being incomplete and then a complete answer comes along that is longer, more complex, and fails to showcase the language then you might argue to append the wrong answer with an explanation of what it misses out and why it should be kept. But we really try and stick to the task description so a reason for keeping should be strong.
An example if this is where I asked for an example to be preserved in the Range Expansion task as a language had a large part of the spec in-built. They seem to have kept both examples which is great, but I can't think of another example off-hand. --Paddy3118 (talk) 10:35, 8 June 2013 (UTC)

"Herzliches Dankeschön" for correcting the errors on Collections

--Siskus (talk) 11:51, 27 June 2014 (UTC)

Long examples

Hi Walterpachl, might you consider moving SUDOKU version 3 to that REXX sub page as it is quite long? Thanks. --Paddy3118 (talk) 14:44, 3 October 2014 (UTC)

I'd gladly do it if you tell me how :-) --Walterpachl (talk) 18:52, 3 October 2014 (UTC)
and how should this reference look like?

/* REXX --------------------------------------------------------------- <lang rexx></lang> I did translate it from the code shown under PL/I

I think I saw a

Translation of: D

tag somewhere.--Paddy3118 (talk) 23:47, 3 October 2014 (UTC)

Follow the link at Sudoku#REXX. I also consolidated a few other wayward REXX pages for version 1 and added the other versions.
This kind of thing is done for other long examples for example Knapsack_problem/Unbounded#Python --Paddy3118 (talk) 23:47, 3 October 2014 (UTC)
Actually I want to have my date + name in my examples (even if that's against your philosophy. Searching fro authors IS a pain in the neck (voice of experience) ). What does the indirection buy? It can't be storage space, can it? Anywhere described on RC?--Walterpachl (talk) 07:09, 4 October 2014 (UTC)
There is very little that is written down about the way RC and other wiki's work. It is left mainly to peoples reasonable consensus and following what works elsewhere. In this case it comes from wikipedias practice of not signing entries but signing all talk page entries. It has the effect of emphasizing that not only is the task and its entries a collaborative effort, but also encourages others to improve any code submitted. Signing code is like saying "This is mine. Do not touch". As soon as anyone were to change something then a name in comments would not match reality. Given the way that wiki's encourage improvement, using history to determine who wrote what is the most accurate way of determining something that is not often needed. --Paddy3118 (talk) 08:34, 4 October 2014 (UTC)
if you submit code to a wiki such as this then you should understand that improving such examples by the community is normal and to be expected. It may be a little hard to let go at first, but a lot of people, me included, learn a lot by understanding others viewpoints --Paddy3118 (talk) 08:43, 4 October 2014 (UTC)
my comment boxes allow, of course, for changes by peers by their adding a line containing date, name, and reasons for changes made. That's what we did at IBM. But I shall refrain from my stamping programs in the future.--Walterpachl (talk) 19:29, 4 October 2014 (UTC)
Thanks Walterpachl, it's appreciated. --Paddy3118 (talk) 21:16, 4 October 2014 (UTC)

Another transportation problem

On tio, I modified a copy of Transportation_problem#REXX to start with

4 5        # of sources / # of demands
50 60 50 50    sources
30 20 70 30 60   demands
16 16 13 22 17     cost matrix
14 14 13 19 15
19 19 20 23 50
50 12 50 15 11

and found I also had to change the first Do i=1 To 5 in init to Do i=1 To 7, then it worked fine. Obviously it would be better to analyse the first line and then loop/read from 2 to (number of sources+3). It also strikes me the code on that page should actually be on Vogel's_approximation_method and maybe try stepping stone or something else on the tp page, jmo. --Pete Lomax (talk) 12:58, 10 December 2020 (UTC)

Two problems or three:

I discovered Vogel's page only after I finisher this pgm. And my pgm does not properly work with Vogel's data :-(
I am still trying to understand how to optimize :-(
I don't know how t proüerly sign such a text.
Anyway, thanks for caring :-) Walter

You sign posts by typing --~~~~ but not inside <nowiki></nowiki> as I just did then ==>> --Pete Lomax (talk) 18:41, 10 December 2020 (UTC)
Testing --Walter Pachl 19:05, 10 December 2020 (UTC)