Find function in text

Question

I'm re-designing a mathematics program for students. The original program was written in adobe flash. This time I am doing it in PHP and JavaScript.

In the original program there are several XML files with hundreds of mathematical questions and some of which are fractions. Those fractions are written as: #(1,4). I want to make an function called # which can make classic fractions.

The problem: there is normal text around the #(1,3) and it is not separated with quotations. How can I let the browser know there is a function in the text? Example:

  <question>what is #(2,8) divided by #(3,4)</question>

I hope you know how to do this. Thanks.

What do you mean by `let the browser know`? Are you just trying to parse the values and display it as a fraction? — Amal Murali, Sep 19 '13 at 21:31
I want to let javascript or php handle the function to make it a fraction. But now they dont recognize the function between the text. — Mark, Sep 19 '13 at 21:33
Yes. Or even better: like this http://stackoverflow.com/questions/13878772/how-to-display-classic-fractions-in-css-javascript — Mark, Sep 19 '13 at 21:37
I like the "but now", hey you need to do some research and look for javascript latex, or even jquery tex/latex. — Kyslik, Sep 19 '13 at 21:38
I worked-around the link you gave, check if it satisfies you now :) — Adrien Gorrell, Sep 19 '13 at 21:53

Mike 'Pomax' Kamermans · Accepted Answer · 2013-09-19T21:45:50.700

Without more detailed information:

var s = "<question>what is #(2,8) divided by #(3,4)</question>";
var t = s.replace(/(^|\s|>)#\((\d+),(\d+)\)($|\s|<)/g, "$1<span class='fraction'><span class='numerator'>$2</span><span class='denominator'>$3</span></span>$4");

t is now

"<question>what is <span class='fraction'><span class='numerator'>2</span><span class='denominator'>8</span></span> divided by <span class='fraction'><span class='numerator'>3</span><span class='denominator'>4</span></span></question>"

So: regular expression where you find #(...,...) where the ... are numbers, and the "function" strings are either surrounded by white space, the start/end of the sentence, or angle brackets.

However, rewriting it to MathJax MathML or LaTeX format (http://mathjax.org) instead will look much nicer.

and updated because I forgot to put the "around the function" bits back in the replacement. — Mike 'Pomax' Kamermans, Sep 19 '13 at 21:46

score 0 · Answer 2 · answered Sep 19 '13 at 21:37

0

Regular expression!

^#$[\d]+,[\d]+$$

This will match anything that begins/ends with #([*number(s)*],[*number(s)*])

You can have PHP do this and format however you need it.

answered Sep 19 '13 at 21:37

Dakotah Hicock

380
2
15

This will match the pattern correctly, but only if it's the only thing on the line. – Surreal Dreams Sep 20 '13 at 15:35

score 0 · Answer 3 · answered Sep 19 '13 at 21:38

You could parse the text in PHP, using preg_replace(). Here's an example of how it might work:

preg_replace( "/#\((\d+),(\d+)\)/" , "$1/$2" , $question );

You'd want to write a loop to get each question from the xml and run this line of code on it.

This will take a line like this:

what is #(2,8) divided by #(3,4)

And give you this:

what is 2/8 divided by 3/4

You can tinker with this code and see it work in the PHP Sandbox.

score 0 · Answer 4 · edited May 23 '17 at 12:28

As you pointed out... there is a link treating part of your problem already.

How to display "Classic" built-up fractions with an horizontal line in CSS / JavaScript?

I worked-around the jsfiddle of the link to satisfy your needs :

http://jsfiddle.net/xW7d8/156/

The only change resides in the javascript, changing your #(1,2) to 1/2. And then the existing script does the job.

$('.fraction').each(function(key, value) {
    $this = $(this) ;
    var s = $this.text() ;
    var n = s.replace(/#\((\d+),(\d+)\)/g, "$1/$2") ;
    var split = n.split("/")
    if( split.length == 2 ){
        $this.html('<span class="top">'+split[0]+'</span><span class="bottom">'+split[1]+'</span>')
    }    
});

-- Edit -- Does not take into account the change from <question> String </question> to <span ...> String </span> though. You could use a combination of the jsfiddle and the accepted answer :)

Find function in text

4 Answers4