Axis::Grid PHP Method

    public function Grid($min, $round_up = false)
    {
        $this->uneven = false;
        $negative = $this->min_value < 0;
        $min_sub = max($min, $this->length / 200);
        if ($round_up || $this->min_value == $this->max_value) {
            $this->max_value += $this->min_unit;
        }
        $scale = $this->max_value - $this->min_value;
        // get magnitude from greater of |+ve|, |-ve|
        $abs_min = abs($this->min_value);
        $magnitude = max(pow(10, floor(log10($scale))), $this->min_unit);
        if ($this->fit) {
            $count = ceil($scale / $magnitude);
        } else {
            $count = ceil($this->max_value / $magnitude) - floor($this->min_value / $magnitude);
        }
        if ($count <= 5 && $magnitude > $this->min_unit) {
            $magnitude *= 0.1;
            $count = ceil($this->max_value / $magnitude) - floor($this->min_value / $magnitude);
        }
        $neg_count = ceil($abs_min / $magnitude);
        $this->find_division($this->length, $min_sub, $count, $neg_count, $magnitude);
        $grid = $this->length / $count;
        // guard this loop in case the numbers are too awkward to fit
        $guard = 20;
        while ($grid < $min && --$guard) {
            $this->find_division($this->length, $min_sub, $count, $neg_count, $magnitude);
            $grid = $this->length / $count;
        }
        if ($guard == 0) {
            // could not find a division
            while ($grid < $min && $count > 1) {
                $count *= 0.5;
                $magnitude *= 2;
                $grid = $this->length / $count;
                $this->uneven = true;
            }
        } elseif (!$this->fit && $magnitude > $this->min_unit && $grid / $min > 2) {
            // division still seems a bit coarse
            $this->sub_division($this->length, $min_sub, $count, $neg_count, $magnitude);
            $grid = $this->length / $count;
        }
        $this->unit_size = $this->length / ($magnitude * $count);
        $this->zero = $negative ? $neg_count * $grid : -$this->min_value * $grid / $magnitude;
        return $grid;
    }