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<?php |
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/** |
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* Copyright (C) 2011-2022 Graham Breach |
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* |
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* This program is free software: you can redistribute it and/or modify |
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* it under the terms of the GNU Lesser General Public License as published by |
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* the Free Software Foundation, either version 3 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public License |
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* along with this program. If not, see <http://www.gnu.org/licenses/>. |
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*/ |
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/** |
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* For more information, please contact <graham@goat1000.com> |
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*/ |
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|
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namespace Goat1000\SVGGraph; |
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|
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/** |
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* Class for calculating axis measurements |
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*/ |
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class Axis { |
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|
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protected $length; |
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protected $max_value; |
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protected $min_value; |
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protected $unit_size; |
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protected $min_unit; |
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protected $min_space; |
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protected $fit; |
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protected $zero; |
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protected $units_before; |
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protected $units_after; |
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protected $decimal_digits; |
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protected $uneven = false; |
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protected $rounded_up = false; |
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protected $direction = 1; |
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protected $label_callback = false; |
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protected $values = false; |
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protected $tightness = 1; |
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protected $grid_spacing; |
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|
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public function __construct($length, $max_val, $min_val, $min_unit, $min_space, |
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$fit, $units_before, $units_after, $decimal_digits, $label_callback, $values) |
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{ |
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if($max_val <= $min_val && $min_unit == 0) |
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throw new \Exception('Zero length axis (min >= max)'); |
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$this->length = $length; |
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$this->max_value = $max_val; |
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$this->min_value = $min_val; |
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$this->min_unit = $min_unit; |
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$this->min_space = $min_space; |
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$this->fit = $fit; |
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$this->units_before = $units_before; |
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$this->units_after = $units_after; |
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$this->decimal_digits = $decimal_digits; |
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$this->label_callback = $label_callback; |
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$this->values = $values; |
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} |
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|
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/** |
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* Returns min for an axis based on its min and max values |
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*/ |
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public static function calcMinimum($min_value, $max_value, $allow_zero, |
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$prefer_zero) |
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{ |
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if($allow_zero && $prefer_zero) { |
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if($min_value > 0) |
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return 0; |
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if($max_value < 0) |
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$max_value = 0; |
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} |
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|
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if($min_value > 0) { |
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$mag = floor(log10($min_value)); |
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if($allow_zero) { |
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$mag1 = floor(log10($max_value)); |
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if($mag1 > $mag) |
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return 0; |
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} |
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$d = pow(10, $mag); |
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$min_value = floor($min_value / $d) * $d; |
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} |
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return $min_value; |
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} |
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|
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/** |
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* Returns max for an axis based on its min and max values |
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*/ |
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public static function calcMaximum($min_value, $max_value, $allow_zero, |
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$prefer_zero) |
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{ |
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if($max_value >= 0) |
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return $max_value; |
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|
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// instead of duplicating code, negate values and pass to calcMinimum() |
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$neg_max = Axis::calcMinimum(-$max_value, -$min_value, $allow_zero, |
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$prefer_zero); |
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if($neg_max > 0) |
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return -$neg_max; |
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return 0; |
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} |
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|
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/** |
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* Allow length adjustment |
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*/ |
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public function setLength($l) |
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{ |
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$this->length = $l; |
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} |
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|
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/** |
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* Returns the axis length |
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*/ |
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public function getLength() |
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{ |
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return $this->length; |
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} |
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|
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/** |
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* Sets the tightness option |
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*/ |
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public function setTightness($t) |
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{ |
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$this->tightness = $t; |
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} |
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|
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/** |
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* Returns a score for "niceness" |
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*/ |
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private function nice($n) |
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{ |
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if($this->min_unit) { |
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$d = $n / $this->min_unit; |
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if($d != floor($d)) |
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return 0; |
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} |
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|
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// convert to string |
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$nn = new Number($n); |
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$nn->precision = 5; |
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$s = (string)$nn; |
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|
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$niceness = [ |
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'0.1' => 50, |
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'0.5' => 40, |
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'0.2' => 25, |
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'2.5' => 25, |
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'1.5' => 20, |
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'0.3' => 10, |
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'0.4' => 10, |
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'1' => 100, |
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'5' => 95, |
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'2' => 95, |
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'3' => 45, |
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'4' => 40, |
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'6' => 30, |
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'8' => 20, |
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'7' => 10, |
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'9' => 5, |
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'25' => 95, |
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'15' => 40, |
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'75' => 30, |
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]; |
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|
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$digits = $s; |
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if(preg_match('/^([1-9]{1,2})(0*)$/', $s, $parts)) { |
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// integer with one or two non-zero digit |
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$digits = $parts[1]; |
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} elseif(preg_match('/^0\.(0+)([1-9]{1,2})$/', $s, $parts)) { |
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// float with leading zeroes |
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$digits = $parts[2]; |
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} |
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|
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return isset($niceness[$digits]) ? $niceness[$digits] : 0; |
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} |
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|
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/** |
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* Determine the axis divisions |
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*/ |
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private function findDivision($length, $min, &$count, &$neg_count, &$magnitude) |
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{ |
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if($this->tightness && $length / $count >= $min) { |
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return; |
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} |
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|
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$c = $count - 1; |
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$inc = 0; |
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|
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// $max_inc is how many extra steps the axis can grow by |
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if($this->fit) |
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$max_inc = 0; |
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else |
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$max_inc = $count / ($this->tightness ? 5 : 2); |
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|
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$candidates = []; |
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while($c > 1) { |
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$m = ($count + $inc) / $c; |
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$new_magnitude = $m * $magnitude; |
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$l = $length / $c; |
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$nc = $neg_count; |
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|
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$accept = false; |
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$niceness = $this->nice($new_magnitude); |
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if($niceness > 0 && $l >= $min) { |
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$accept = true; |
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|
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// negative values mean an extra check |
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if($nc) { |
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$accept = false; |
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$nm = $nc / $m; |
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|
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if(floor($nm) === $nm) { |
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$nc = $nm; |
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$accept = true; |
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} else { |
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|
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// negative section doesn't divide cleanly, try adding from $inc |
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if($inc) { |
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for($i = 1; $i <= $inc; ++$i) { |
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$cc = $nc + $i; |
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$nm = ($nc + $i) / $m; |
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|
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if(floor($nm) === $nm) { |
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$nc = $nm; |
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$accept = true; |
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break; |
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} |
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} |
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} |
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} |
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} |
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} |
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|
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if($accept) { |
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$pos = ($c - $nc) * $new_magnitude; |
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$neg = $nc * $new_magnitude; |
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$pos_niceness = $this->nice($pos); |
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$neg_niceness = $this->nice($neg); |
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|
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if($this->tightness || $neg_niceness || $pos_niceness) { |
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// this division is acceptable, cost and store it |
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$cost = $m; |
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if($this->tightness) { |
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$cost += $inc * 1.5; |
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} else { |
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// increasing the length is not as costly |
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$cost += $inc * 0.5; |
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|
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// reduce cost for nicer divisions |
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$cost -= $niceness / 50; |
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|
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// adjust cost for axis ends |
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if($nc) { |
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if($neg_niceness) { |
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$cost -= $neg_niceness / 100; |
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if($pos_niceness) |
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$cost -= $pos_niceness / 100; |
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} else { |
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// poor choice |
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$cost += 3; |
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} |
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} elseif($pos_niceness) { |
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$cost -= $pos_niceness / 100; |
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} |
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} |
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|
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$candidate = [ |
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// usort requires ints to work properly |
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'cost' => intval(1e5 * $cost), |
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'magnitude' => $new_magnitude, |
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'count' => $c, |
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'neg_count' => $nc, |
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|
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// these are only used for tuning / debugging |
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'm' => $m, |
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'real_cost' => $cost, |
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'max_pos' => $pos, |
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'max_neg' => $neg, |
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'nice_mag' => $niceness, |
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'nice_pos' => $pos_niceness, |
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'nice_neg' => $neg_niceness, |
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]; |
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|
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$candidates[] = $candidate; |
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} |
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} |
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|
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if($inc < $max_inc) { |
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// increase the number of base divisions |
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++$inc; |
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continue; |
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} |
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|
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--$c; |
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$inc = 0; |
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} |
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|
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if(empty($candidates)) |
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return; |
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|
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usort($candidates, function($a, $b) { return $a['cost'] - $b['cost']; }); |
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$winner = $candidates[0]; |
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$magnitude = $winner['magnitude']; |
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$count = $winner['count']; |
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$neg_count = $winner['neg_count']; |
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} |
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|
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/** |
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* Sets the bar style (which means an extra unit) |
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*/ |
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public function bar() |
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{ |
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if(!$this->rounded_up) { |
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$this->max_value += $this->min_unit; |
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$this->rounded_up = true; |
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} |
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} |
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|
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/** |
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* Sets the direction of axis points |
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*/ |
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public function reverse() |
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{ |
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$this->direction = -1; |
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} |
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|
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/** |
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* Returns TRUE if the axis is reversed |
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*/ |
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public function reversed() |
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{ |
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return $this->direction < 0; |
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} |
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|
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/** |
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* Returns the grid spacing |
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*/ |
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protected function grid() |
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{ |
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$min_space = $this->min_space; |
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$this->uneven = false; |
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$negative = $this->min_value < 0; |
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$min_sub = max($min_space, $this->length / 200); |
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|
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if($this->min_value == $this->max_value) |
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$this->max_value += $this->min_unit; |
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$scale = $this->max_value - $this->min_value; |
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|
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$abs_min = abs($this->min_value); |
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$magnitude = max(pow(10, floor(log10($scale))), $this->min_unit); |
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if($this->min_value > 0 || $this->fit) { |
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$count = ceil($scale / $magnitude); |
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} else { |
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$count = ceil($this->max_value / $magnitude) - |
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floor($this->min_value / $magnitude); |
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} |
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|
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if($count <= 5 && $magnitude > $this->min_unit) { |
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$magnitude *= 0.1; |
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$count = ceil($this->max_value / $magnitude) - |
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floor($this->min_value / $magnitude); |
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} |
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|
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$neg_count = $this->min_value < 0 ? ceil($abs_min / $magnitude) : 0; |
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$this->findDivision($this->length, $min_sub, $count, $neg_count, |
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$magnitude); |
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$grid = $this->length / $count; |
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|
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// guard this loop in case the numbers are too awkward to fit |
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$guard = 10; |
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while($grid < $min_space && --$guard) { |
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$this->findDivision($this->length, $min_sub, $count, $neg_count, |
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$magnitude); |
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$grid = $this->length / $count; |
| 381 |
} |
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if($guard == 0) { |
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// could not find a division |
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while($grid < $min_space && $count > 1) { |
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$count *= 0.5; |
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$neg_count *= 0.5; |
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$magnitude *= 2; |
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$grid = $this->length / $count; |
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$this->uneven = true; |
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} |
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} |
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|
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$this->unit_size = $this->length / ($magnitude * $count); |
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$this->zero = $negative ? $neg_count * $grid : |
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-$this->min_value * $grid / $magnitude; |
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|
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return $grid; |
| 398 |
} |
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|
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/** |
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* Returns the size of a unit in grid space |
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*/ |
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public function unit() |
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{ |
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if(!isset($this->unit_size)) |
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$this->grid(); |
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|
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return $this->unit_size; |
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} |
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|
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/** |
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* Returns the distance along the axis where 0 should be |
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*/ |
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public function zero() |
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{ |
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if(!isset($this->zero)) |
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$this->grid(); |
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|
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return $this->zero; |
| 420 |
} |
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|
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/** |
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* Returns TRUE if the grid spacing does not fill the grid |
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*/ |
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public function uneven() |
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{ |
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return $this->uneven; |
| 428 |
} |
| 429 |
|
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/** |
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* Returns the distance in pixels $u takes from $pos |
| 432 |
*/ |
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public function measureUnits($pos, $u) |
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{ |
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// on an ordinary axis this works fine |
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$l = $this->position($u); |
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$zero = $this->position(0); |
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return $l - $zero; |
| 439 |
} |
| 440 |
|
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/** |
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* Returns the position of a value on the axis |
| 443 |
*/ |
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public function position($index, $item = null) |
| 445 |
{ |
| 446 |
$value = $index; |
| 447 |
if($item !== null && !$this->values->associativeKeys()) |
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$value = $item->key; |
| 449 |
if(!is_numeric($value)) |
| 450 |
return null; |
| 451 |
return $this->zero() + ($value * $this->unit()); |
| 452 |
} |
| 453 |
|
| 454 |
/** |
| 455 |
* Returns the position of an associative key, if possible |
| 456 |
*/ |
| 457 |
public function positionByKey($key) |
| 458 |
{ |
| 459 |
if($this->values && $this->values->associativeKeys()) { |
| 460 |
|
| 461 |
// only need to look through dataset 0 because multi-dataset graphs |
| 462 |
// convert to structured |
| 463 |
$index = 0; |
| 464 |
foreach($this->values[0] as $item) { |
| 465 |
if($item->key == $key) { |
| 466 |
return $this->zero() + ($index * $this->unit()); |
| 467 |
} |
| 468 |
++$index; |
| 469 |
} |
| 470 |
} |
| 471 |
return null; |
| 472 |
} |
| 473 |
|
| 474 |
/** |
| 475 |
* Returns the position of the origin |
| 476 |
*/ |
| 477 |
public function origin() |
| 478 |
{ |
| 479 |
// for a linear axis, it should be the zero point |
| 480 |
return $this->zero(); |
| 481 |
} |
| 482 |
|
| 483 |
/** |
| 484 |
* Returns the value at a position on the axis |
| 485 |
*/ |
| 486 |
public function value($position) |
| 487 |
{ |
| 488 |
return ($position - $this->zero()) / $this->unit(); |
| 489 |
} |
| 490 |
|
| 491 |
/** |
| 492 |
* Return the before units text |
| 493 |
*/ |
| 494 |
public function beforeUnits() |
| 495 |
{ |
| 496 |
return $this->units_before; |
| 497 |
} |
| 498 |
|
| 499 |
/** |
| 500 |
* Return the after units text |
| 501 |
*/ |
| 502 |
public function afterUnits() |
| 503 |
{ |
| 504 |
return $this->units_after; |
| 505 |
} |
| 506 |
|
| 507 |
/** |
| 508 |
* Returns a single GridPoint |
| 509 |
*/ |
| 510 |
protected function getGridPoint($position, $value) |
| 511 |
{ |
| 512 |
$key = $text = $value; |
| 513 |
$item = null; |
| 514 |
|
| 515 |
if($this->values) { |
| 516 |
|
| 517 |
// try structured data first |
| 518 |
$item = $this->values->getItem($value); |
| 519 |
if($item !== null && $this->values->getData($value, 'axis_text', $text)) |
| 520 |
return new GridPoint($position, $text, $value, $item); |
| 521 |
|
| 522 |
// use the key if it is not the same as the value |
| 523 |
$key = $this->values->getKey($value); |
| 524 |
} |
| 525 |
|
| 526 |
// if there is a callback, use it |
| 527 |
if(is_callable($this->label_callback)) { |
| 528 |
// assoc keys should have integer indices |
| 529 |
if($this->values && $this->values->associativeKeys()) |
| 530 |
$value = (int)round($value); |
| 531 |
$text = call_user_func($this->label_callback, $value, $key); |
| 532 |
return new GridPoint($position, $text, $value, $item); |
| 533 |
} |
| 534 |
|
| 535 |
if($key !== $value) |
| 536 |
return new GridPoint($position, $key, $value, $item); |
| 537 |
|
| 538 |
$n = new Number($value, $this->units_after, $this->units_before); |
| 539 |
$text = $n->format($this->decimal_digits); |
| 540 |
return new GridPoint($position, $text, $value, $item); |
| 541 |
} |
| 542 |
|
| 543 |
/** |
| 544 |
* Returns the grid points as an array of GridPoints |
| 545 |
* if $start is NULL, just set up the grid spacing without returning points |
| 546 |
*/ |
| 547 |
public function getGridPoints($start) |
| 548 |
{ |
| 549 |
$this->grid_spacing = $spacing = $this->grid(); |
| 550 |
$dlength = $this->length + $spacing * 0.5; |
| 551 |
if($dlength / $spacing > 10000) { |
| 552 |
$pcount = $dlength / $spacing; |
| 553 |
throw new \Exception('Too many grid points (' . $this->min_value . '->' . |
| 554 |
$this->max_value . ' = ' . $pcount . ' points @ ' . $spacing . 'px separation)'); |
| 555 |
} |
| 556 |
if($start === null) |
| 557 |
return; |
| 558 |
|
| 559 |
$c = $pos = 0; |
| 560 |
$points = []; |
| 561 |
while($pos < $dlength) { |
| 562 |
$value = ($pos - $this->zero) / $this->unit_size; |
| 563 |
$position = $start + ($this->direction * $pos); |
| 564 |
$points[] = $this->getGridPoint($position, $value); |
| 565 |
$pos = ++$c * $spacing; |
| 566 |
} |
| 567 |
// uneven means the divisions don't fit exactly, so add the last one in |
| 568 |
if($this->uneven) { |
| 569 |
$pos = $this->length - $this->zero; |
| 570 |
$value = $pos / $this->unit_size; |
| 571 |
$position = $start + ($this->direction * $this->length); |
| 572 |
$points[] = $this->getGridPoint($position, $value); |
| 573 |
} |
| 574 |
|
| 575 |
if($this->direction < 0) { |
| 576 |
usort($points, function($a, $b) { return $b->position - $a->position; }); |
| 577 |
} else { |
| 578 |
usort($points, function($a, $b) { return $a->position - $b->position; }); |
| 579 |
} |
| 580 |
|
| 581 |
$this->grid_spacing = $spacing; |
| 582 |
return $points; |
| 583 |
} |
| 584 |
|
| 585 |
/** |
| 586 |
* Returns the grid subdivision points as an array |
| 587 |
*/ |
| 588 |
public function getGridSubdivisions($min_space, $min_unit, $start, $fixed) |
| 589 |
{ |
| 590 |
if(!$this->grid_spacing) |
| 591 |
throw new \Exception('grid_spacing not set'); |
| 592 |
|
| 593 |
$subdivs = []; |
| 594 |
$spacing = $this->findSubdiv($this->grid_spacing, $min_space, $min_unit, |
| 595 |
$fixed); |
| 596 |
if(!$spacing) |
| 597 |
return $subdivs; |
| 598 |
|
| 599 |
$c = $pos1 = $pos2 = 0; |
| 600 |
$pos1 = $c * $this->grid_spacing; |
| 601 |
while($pos1 + $spacing < $this->length) { |
| 602 |
$d = 1; |
| 603 |
$pos2 = $d * $spacing; |
| 604 |
while($pos2 < $this->grid_spacing) { |
| 605 |
$subdivs[] = new GridPoint($start + (($pos1 + $pos2) * $this->direction), '', 0); |
| 606 |
++$d; |
| 607 |
$pos2 = $d * $spacing; |
| 608 |
} |
| 609 |
++$c; |
| 610 |
$pos1 = $c * $this->grid_spacing; |
| 611 |
} |
| 612 |
return $subdivs; |
| 613 |
} |
| 614 |
|
| 615 |
/** |
| 616 |
* Find the subdivision size |
| 617 |
*/ |
| 618 |
private function findSubdiv($grid_div, $min, $min_unit, $fixed) |
| 619 |
{ |
| 620 |
if(is_numeric($fixed)) |
| 621 |
return $this->unit_size * $fixed; |
| 622 |
|
| 623 |
$D = $grid_div / $this->unit_size; // D = actual division size |
| 624 |
$min = max($min, $min_unit * $this->unit_size); // use the larger minimum value |
| 625 |
$max_divisions = (int)floor($grid_div / $min); |
| 626 |
|
| 627 |
// can we subdivide at all? |
| 628 |
if($max_divisions <= 1) |
| 629 |
return null; |
| 630 |
|
| 631 |
// convert $D to an integer in the 100's range |
| 632 |
$D1 = (int)round(100 * (pow(10,-floor(log10($D)))) * $D); |
| 633 |
for($divisions = $max_divisions; $divisions > 1; --$divisions) { |
| 634 |
// if $D1 / $divisions is not an integer, $divisions is no good |
| 635 |
$dq = $D1 / $divisions; |
| 636 |
if($dq - floor($dq) == 0) |
| 637 |
return $grid_div / $divisions; |
| 638 |
} |
| 639 |
return null; |
| 640 |
} |
| 641 |
} |
| 642 |
|
| 643 |
|
