/** * Initializes the record set and uses the database handle to get the column list contained in * the query that created this object. * * @return void * @see lithium\data\model\RecordSet::$_columns * @todo The part that uses _handle->columns() should be rewritten so that the column list * is coming from the query object. */ protected function _init() { parent::_init(); if ($this->_handle && $this->_result) { $this->_columns = $this->_handle->columns($this->_query, $this->_result, $this); } }
/** * Estimates the lambda parameter from the dataset. * * @param object $invX inverted X matrix for dataset (essentially a posting * list of features in X) * @return float lambda estimate */ function estimateLambdaNorm($invX) { $sqNorm = 0; foreach ($invX->iterateData() as $entry) { $Xij = $entry[2]; $sqNorm += $Xij * $Xij; } $m = $invX->rows(); $n = $invX->columns(); $sigmaSq = $n * $m / $sqNorm; return sqrt(2) / sqrt($sigmaSq); }