/**
* Validate the formula.
* @param string $formula
* @return boolean true if calculation possible, false otherwise
*/
function validate_formula($formulastr)
{
global $CFG;
require_once $CFG->libdir . '/mathslib.php';
$formulastr = grade_item::normalize_formula($formulastr, $this->courseid);
if (empty($formulastr)) {
return true;
}
if (strpos($formulastr, '=') !== 0) {
return get_string('errorcalculationnoequal', 'grades');
}
// get used items
if (preg_match_all('/##gi(\\d+)##/', $formulastr, $matches)) {
$useditems = array_unique($matches[1]);
// remove duplicates
} else {
$useditems = array();
}
// MDL-11902
// unset the value if formula is trying to reference to itself
// but array keys does not match itemid
if (!empty($this->id)) {
$useditems = array_diff($useditems, array($this->id));
//unset($useditems[$this->id]);
}
// prepare formula and init maths library
$formula = preg_replace('/##(gi\\d+)##/', '\\1', $formulastr);
$formula = new calc_formula($formula);
if (empty($useditems)) {
$grade_items = array();
} else {
$gis = implode(',', $useditems);
$sql = "SELECT gi.*\n FROM {$CFG->prefix}grade_items gi\n WHERE gi.id IN ({$gis}) and gi.courseid={$this->courseid}";
// from the same course only!
if (!($grade_items = get_records_sql($sql))) {
$grade_items = array();
}
}
$params = array();
foreach ($useditems as $itemid) {
// make sure all grade items exist in this course
if (!array_key_exists($itemid, $grade_items)) {
return false;
}
// use max grade when testing formula, this should be ok in 99.9%
// division by 0 is one of possible problems
$params['gi' . $grade_items[$itemid]->id] = $grade_items[$itemid]->grademax;
}
// do the calculation
$formula->set_params($params);
$result = $formula->evaluate();
// false as result indicates some problem
if ($result === false) {
// TODO: add more error hints
return get_string('errorcalculationunknown', 'grades');
} else {
return true;
}
}
public function test_scientific_notation()
{
$formula = new calc_formula('=10e10');
$this->assertWithinMargin($formula->evaluate(), 100000000000.0, 100000000000.0 * 1.0E-15);
$formula = new calc_formula('=10e-10');
$this->assertWithinMargin($formula->evaluate(), 1.0E-9, 100000000000.0 * 1.0E-15);
$formula = new calc_formula('=10e+10');
$this->assertWithinMargin($formula->evaluate(), 100000000000.0, 100000000000.0 * 1.0E-15);
$formula = new calc_formula('=10e10*5');
$this->assertWithinMargin($formula->evaluate(), 500000000000.0, 100000000000.0 * 1.0E-15);
$formula = new calc_formula('=10e10^2');
$this->assertWithinMargin($formula->evaluate(), 1.0E+22, 1.0E+22 * 1.0E-15);
}
public function test_rand_float()
{
$formula = new calc_formula('=rand_float()');
$result = $formula->evaluate();
$this->assertTrue(is_float($result));
}
/**
* Tests special chars
*/
function test__specialchars()
{
$formula = new calc_formula('=gi1 + gi2 + gi11', array('gi1' => 10, 'gi2' => 20, 'gi11' => 30));
$res = $formula->evaluate();
$this->assertEqual($res, 60, 'sum is: %s');
}
/**
*
*/
protected function process_calculations($text)
{
global $CFG;
// HACK removing occurences of [[entryid]] because they are
// currently not resolved in new entries.
$text = str_replace('[[entryid]]', '', $text);
if (preg_match_all("/%%F\\d*:=[^%]*%%/", $text, $matches)) {
require_once "{$CFG->libdir}/mathslib.php";
sort($matches[0]);
// List of formulas.
$formulas = array();
// Formula replacements.
$replacements = array();
// Register all formulas according to formula identifier.
foreach ($matches[0] as $pattern) {
$cleanpattern = trim($pattern, '%');
list($fid, $formula) = explode(':=', $cleanpattern, 2);
// Skip an empty formula.
if (empty($formula) and $formula !== 0) {
continue;
}
isset($formulas[$fid]) or $formulas[$fid] = array();
// Enclose formula in brackets to preserve precedence.
$formulas[$fid][] = "({$formula})";
$replacements[$pattern] = $formula;
}
// Process group formulas in formulas (e.g. _F1_).
// We put 0 if we can't find a replacement so that the formula could be calculated.
foreach ($formulas as $fid => $formulae) {
foreach ($formulae as $key => $formula) {
if (preg_match_all("/_F\\d+_/", $formula, $frefs)) {
foreach ($frefs[0] as $fref) {
$fref = trim($fref, '_');
if (isset($formulas[$fref])) {
$replace = implode(',', $formulas[$fref]);
} else {
$replace = 0;
}
$formula = str_replace("_{$fref}_", $replace, $formula);
}
$formulae[$key] = $formula;
}
}
$formulas[$fid] = $formulae;
}
// Process group formulas in replacements (e.g. _F1_).
// We put 0 if we can't find a replacement so that the formula could be calculated.
foreach ($replacements as $pattern => $formula) {
if (preg_match_all("/_F\\d+_/", $formula, $frefs)) {
foreach ($frefs[0] as $fref) {
$fref = trim($fref, '_');
if (isset($formulas[$fref])) {
$replace = implode(',', $formulas[$fref]);
} else {
$replace = 0;
}
$formula = str_replace("_{$fref}_", $replace, $formula);
}
$replacements[$pattern] = $formula;
}
}
// Calculate.
foreach ($replacements as $pattern => $formula) {
// Number of decimals can be set as ;n at the end of the formula.
$decimals = null;
if (strpos($formula, ';')) {
list($formula, $decimals) = explode(';', $formula);
}
$calc = new \calc_formula("={$formula}");
$result = $calc->evaluate();
if ($result === false) {
// False as result indicates some problem.
// We remove the formula altogether.
$replacements[$pattern] = '';
} else {
// Set decimals.
if (is_numeric($decimals)) {
$result = sprintf("%4.{$decimals}f", $result);
}
$replacements[$pattern] = $result;
}
}
$text = str_replace(array_keys($replacements), $replacements, $text);
}
return $text;
}
/**
* Returns user's calculated grades for the specified grade item.
*
* @param grade_item $gradeitem
* @param array $userids The user ids whose grades should be retrieved.
* @return array|null
*/
protected function get_user_grades_calculated($gradeitem, array $userids)
{
global $CFG;
if (!($df = $this->df)) {
return null;
}
require_once "{$CFG->libdir}/mathslib.php";
$formula = $gradeitem->gradecalc;
// Patterns container.
$patterns = array();
// Users container.
$users = array_fill_keys($userids, array());
// Grades container.
$grades = array();
foreach ($users as $userid => $unused) {
$grades[$userid] = (object) array('id' => $userid, 'userid' => $userid, 'rawgrade' => null);
// Num entries pattern.
if (strpos($formula, '##numentries##') !== false) {
$patterns['##numentries##'] = 0;
if ($numentries = $df->get_entries_count_per_user($df::COUNT_ALL, $userid)) {
foreach ($numentries as $userid => $count) {
$users[$userid]['##numentries##'] = $count->numentries;
}
}
}
// Extract grading field patterns from the formula.
if (preg_match_all("/##\\d*:[^#]+##/", $formula, $matches)) {
// Get the entry ids per user.
$entryids = $df->get_entry_ids_per_user($userid);
foreach ($matches[0] as $pattern) {
$patterns[$pattern] = 0;
list($targetval, $fieldpattern) = explode(':', trim($pattern, '#'), 2);
// Get the field from the pattern.
if (!($field = $df->field_manager->get_field_by_pattern("[[{$fieldpattern}]]"))) {
continue;
}
$uservalues = null;
// Get user values for the pattern.
// The field must either has helper\contentperuser component,
// or be an instance of interface grading.
$helper = "dataformfield_{$field->type}\\helper\\contentperuser";
if (class_exists($helper)) {
$uservalues = $helper::get_content($field, $fieldpattern, $entryids);
} else {
if ($field instanceof mod_dataform\interfaces\grading) {
// BC - this method for grading user values is depracated.
$uservalues = $field->get_user_values($fieldpattern, $entryids, $userid);
}
}
// Leave pattern value at 0 if no user values.
if (!$uservalues) {
continue;
}
// Register pattern values for users.
foreach ($uservalues as $userid => $values) {
// Keep only target val if specified.
if ($targetval) {
foreach ($values as $key => $value) {
if ($value != $targetval) {
unset($values[$key]);
}
}
}
if ($values) {
$users[$userid][$pattern] = implode(',', $values);
}
}
}
}
}
// For each user calculate the formula and create a grade object.
foreach ($grades as $userid => $grade) {
// If no values, no grade for this user.
if (empty($users[$userid])) {
continue;
}
$values = $users[$userid];
$replacements = array_merge($patterns, $values);
$calculation = str_replace(array_keys($replacements), $replacements, $formula);
$calc = new calc_formula("={$calculation}");
$result = $calc->evaluate();
// False as result indicates some problem.
if ($result !== false) {
$grade->rawgrade = $result;
}
}
return $grades;
}
public function test_scientific_notation() {
$formula = new calc_formula('=10e10');
$this->assertEquals($formula->evaluate(), 1e11, '', 1e11*1e-15);
$formula = new calc_formula('=10e-10');
$this->assertEquals($formula->evaluate(), 1e-9, '', 1e11*1e-15);
$formula = new calc_formula('=10e+10');
$this->assertEquals($formula->evaluate(), 1e11, '', 1e11*1e-15);
$formula = new calc_formula('=10e10*5');
$this->assertEquals($formula->evaluate(), 5e11, '', 1e11*1e-15);
$formula = new calc_formula('=10e10^2');
$this->assertEquals($formula->evaluate(), 1e22, '', 1e22*1e-15);
}
