PHP algebraic equation function

Recently while cleaning out some of my old files I came across a PHP class project which I, like every programmer, had started but never finished. I started this class about 3 years ago with intentions of building a larger library of functions which could solve different Leaving Cert maths problems. I never was the best at maths and so I combined something I love, programming, with something I needed to improve, maths! I figured that if I could program a machine to solve the equations I could do it myself. Even though I only wrote one function, it helped me dramatically. Here is a live AJAX demo of the code, and below that is the source code, though I wrote it almost 3 years so do forgive any mistakes or bad code. Just thought I would share it.

You most put spaces between numbers/operators like in the example below for it to work. Also it will only work with X not any other letter. – NOTE: This code is 3 years old


MathFx – Live demo

X = -1

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Source Code

class algebra{

public function solve_x($sum)
{
// checks if sum exists
	if($sum)
	{

		$sum = str_replace("\n", "{line_break}", $sum);
		$sum = split('{line_break}',$sum);
		$chr_no = strlen($sum[0]);
		$sum_array = split(' ',$sum[0]);

	$i = 0;

	while($i < $chr_no)
	{
			$haystack_operators = array('+','-');

			// check to see if $sum_array[$i] is a number//
			if(is_numeric($sum_array[$i])){

				$a = $i - 1;

				$haystack_operators = array('=');

					if(!in_array($sum_array[$a],$haystack_operators ))
					{
						// changes the sign
						if($sum_array[$a] == "-")
						{
							$sign =  "+";
						}
						else
						{
							$sign =  "-";
						};

						$cal[$i] = $sign.$sum_array[$i];
					}
					else
					{
						$theSumOf = $sum_array[$i];
					};

		};
			$needle_notation = 'x,X';

			if(strpbrk($sum_array[$i],$needle_notation))
				{
				// removes the x from the equestion eg 2x -> 2
				$diviser[$i] = str_replace($needle_notation," ",$sum_array[$i]);
				};

			$i++;
		};

			if($cal)
			{
				$calu = array_sum($cal);
			};

			if($diviser)
			{
				$diviser = array_sum($diviser);
			};

			$theSumOf = $theSumOf+$calu;

			if($diviser)
			{
				$ans = $theSumOf/$diviser;
			};

				return $ans;
		};

	}// End of method

}// End of class

About the Author

Ciarán McCann

Flax Project Founder - Ciarán McCann is an extremely passionate and motivated programmer who has been programming for about 4 years now. Currently attending Carlow I.T studying computer games development. He has experience in many different programming languages, markup languages and general technologies. His role in the Flax Project is as a blogger/Web Designer and Flax Engine programmer. Please excuse any bad grammar/spelling, I am a bit on the Dyslexic side. Follow me on Twitter for info on what I am working on.

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