function generarEstadisticas($ids)
{
$this->numeroTweetsPuntuados = count($ids);
$this->numeroTweets = Grades::getNumberTweetsOfUserInGroup($this->alumno->id, $this->group->id);
$notas = Grades::getNotaMediaYTotalofUserinGroup($this->alumno->id, $this->group->id);
$this->notaMedia = number_format(reset($notas), 2);
$this->notaTotal = number_format(key($notas), 2);
if (empty($this->notaTotal)) {
$this->notaTotal = number_format(0, 2);
}
}