Scale an SVG path element with a simple javascript function

scaleSVGPath.js

function scalePathUp(path, num) {
	// make sure num is > 0 and DOM element path has "d" attribute
	if ( num <= 0 || typeof path.getAttribute("d") !== "string" ) {return false;}

	var coords = [],
		fragmentsAr = [],
		idx,
		jdx,
		kdx,
		lettersAr = [],
		pattern = /[achlqstvz]/gi, 
		pathD = path.getAttribute("d"),
		start = 0,
		subfragAr = [];

	// preserve original d 
	path.setAttribute("originalD", pathD);

	// Find fragments of d starting at any of the following letters: A,a,C,c,H,h,L,l,Q,q,S,s,T,t,V,v,Z or z (see SVG Path spec). First fragment can start with anything (M or m expected).
	// 
	// start by listing each occurence of one of these letters
	lettersAr = pathD.match(pattern);
	// slice d into fragments, each of which starts with one of these letters
	for (idx = 0; idx < lettersAr.length; idx++) {
		fragmentsAr.push( pathD.slice( start, pathD.indexOf( lettersAr[idx]) ) );
		start = pathD.indexOf( lettersAr[idx] );
	};
	// don't forget the last one...
	fragmentsAr.push( pathD.slice( start));
	// for each fragment that doesn't start with M or m, create an array of strings that were separated by spaces; the first one should just be a letter, but the others are expected to be floating-point numbers (typically 2) separated by a comma(s)
	for (idx = 0; idx < fragmentsAr.length; idx++) {
		if (fragmentsAr[idx].charAt(0) === 'M' || fragmentsAr[idx].charAt(0) === 'm') {continue;}
		subfragAr = fragmentsAr[idx].split(" ");
		// split up the pairs (or larger groups) of numbers
		for (jdx = 0; jdx < subfragAr.length; jdx++) {
			coords = subfragAr[jdx].split(",");
			// finally do the multiplication on each number; ignore non-numbers
			for (kdx = 0; kdx < coords.length; kdx++) {
				if ( parseFloat(coords[kdx]) == coords[kdx] ) {
					coords[kdx] *= num; // AT LAST!
				}
			};
			// squish new numbers back together into comma-separated groups (typically pairs)
			subfragAr[jdx] = coords.join(",");
		};
		// squish strings back together separated by spaces
		fragmentsAr[idx] = subfragAr.join(" ");
	};
	// assemble new "d" from updated fragments
	pathD = fragmentsAr.join("");
	path.setAttribute("d", pathD);
	return true;
}