private String evaluatePtSegDistSqFunction(final String clause) {
		if (clause == null || clause.equals(""))
			return null;
		int i = clause.indexOf("(");
		int j = clause.lastIndexOf(")");
		if (i == -1 || j == -1) {
			out(ScriptEvent.FAILED, "function must be enclosed within parenthesis: " + clause);
			return null;
		}
		String s = clause.substring(i + 1, j).trim();
		String[] t = s.split(",");
		float[] x = parseArray(6, t);
		if (x != null) {
			return "" + Line2D.ptSegDistSq(x[0], x[1], x[2], x[3], x[4], x[5]);
		}
		return null;
	}