Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Abstract discrete indicator.

 *

 * @package   core_analytics

 * @copyright 2017 David Monllao {@link http://www.davidmonllao.com}

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace core_analytics\local\indicator;

defined('MOODLE_INTERNAL') || die();

/**

 * Abstract discrete indicator.

 *

 * @package   core_analytics

 * @copyright 2017 David Monllao {@link http://www.davidmonllao.com}

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

abstract class discrete extends base {

    /**

     * Classes need to be defined so they can be converted internally to individual dataset features.

     *

     * @return string[]

     */

    protected static function get_classes() {

        throw new \coding_exception('Please overwrite get_classes() specifying your discrete-values\' indicator classes');

    }

    /**

     * Returns 1 feature header for each of the classes.

     *

     * @return string[]

     */

    public static function get_feature_headers() {

        $fullclassname = '\\' . get_called_class();

        foreach (static::get_classes() as $class) {

            $headers[] = $fullclassname . '/' . $class;

        }

        return $headers;

    }

    /**

     * Whether the value should be displayed or not.

     *

     * @param float $value

     * @param string $subtype

     * @return bool

     */

    public function should_be_displayed($value, $subtype) {

        if ($value != static::get_max_value()) {

            // Discrete values indicators are converted internally to 1 feature per indicator, we are only interested

            // in showing the feature flagged with the max value.

            return false;

        }

        return true;

    }

    /**

     * Returns the value to display when the prediction is $value.

     *

     * @param float $value

     * @param string $subtype

     * @return string

     */

    public function get_display_value($value, $subtype = false) {

        $displayvalue = array_search($subtype, static::get_classes(), false);

        debugging('Please overwrite \core_analytics\local\indicator\discrete::get_display_value to show something ' .

            'different than the default "' . $displayvalue . '"', DEBUG_DEVELOPER);

        return $displayvalue;

    }

    /**

     * get_display_style

     *

     * @param float $ignoredvalue

     * @param string $ignoredsubtype

     * @return int

     */

    public function get_display_style($ignoredvalue, $ignoredsubtype) {

        // No style attached to indicators classes, they are what they are, a cat,

        // a horse or a sandwich, they are not good or bad.

        return \core_analytics\calculable::OUTCOME_NEUTRAL;

    }

    /**

     * From calculated values to dataset features.

     *

     * One column for each class.

     *

     * @param float[] $calculatedvalues

     * @return float[]

     */

    protected function to_features($calculatedvalues) {

        $classes = static::get_classes();

        foreach ($calculatedvalues as $sampleid => $calculatedvalue) {

            // Using intval as it may come as a float from the db.

            $classindex = array_search(intval($calculatedvalue), $classes, true);

            if ($classindex === false && !is_null($calculatedvalue)) {

                throw new \coding_exception(get_class($this) . ' calculated value "' . $calculatedvalue .

                    '" is not one of its defined classes (' . json_encode($classes) . ')');

            }

            // We transform the calculated value into multiple features, one for each of the possible classes.

            $features = array_fill(0, count($classes), 0);

            // 1 to the selected value.

            if (!is_null($calculatedvalue)) {

                $features[$classindex] = 1;

            }

            $calculatedvalues[$sampleid] = $features;

        }

        return $calculatedvalues;

    }

    /**

     * Validates the calculated value.

     *

     * @param float $calculatedvalue

     * @return true

     */

    protected function validate_calculated_value($calculatedvalue) {

        // Using intval as it may come as a float from the db.

        if (!in_array(intval($calculatedvalue), static::get_classes())) {

            throw new \coding_exception(get_class($this) . ' calculated value "' . $calculatedvalue .

                '" is not one of its defined classes (' . json_encode(static::get_classes()) . ')');

        }

        return true;

    }

}