Update mmdet3d/datasets/scannet_dataset.py, mmdet3d/datasets/kitti_dataset.py,...

Update mmdet3d/datasets/scannet_dataset.py, mmdet3d/datasets/kitti_dataset.py, mmdet3d/datasets/sunrgbd_dataset.py, mmdet3d/datasets/nuscenes_dataset.py files

mmdet3d/datasets/custom_3d.py

@@ -67,9 +67,31 @@ class Custom3DDataset(Dataset):
             self._set_group_flag()
 
     def load_annotations(self, ann_file):
+        """Load annotations from ann_file.
+
+        Args:
+            ann_file (str): Path of the annotation file.
+
+        Returns:
+            list[dict]: List of annotations.
+        """
         return mmcv.load(ann_file)
 
     def get_data_info(self, index):
+        """Get data info according to the given index.
+
+        Args:
+            index (int): Index of the sample data to get.
+
+        Returns:
+            dict: Standard input_dict consists of the
+                data information.
+
+                - sample_idx (str): sample index
+                - pts_filename (str): filename of point clouds
+                - file_name (str): filename of point clouds
+                - ann_info (dict): annotation info
+        """
         info = self.data_infos[index]
         sample_idx = info['point_cloud']['lidar_idx']
         pts_filename = osp.join(self.data_root, info['pts_path'])
@@ -87,6 +109,21 @@ class Custom3DDataset(Dataset):
         return input_dict
 
     def pre_pipeline(self, results):
+        """Initialization before data preparation.
+
+        Args:
+            dict: Dict before data preprocessing.
+
+                - img_fields (list): image fields
+                - bbox3d_fields (list): 3D bounding boxes fields
+                - pts_mask_fields (list): mask fields of points
+                - pts_seg_fields (list): mask fields of point segments
+                - bbox_fields (list): fields of bounding boxes
+                - mask_fields (list): fields of masks
+                - seg_fields (list): segment fields
+                - box_type_3d (str): 3D box type
+                - box_mode_3d (str): 3D box mode
+        """
         results['img_fields'] = []
         results['bbox3d_fields'] = []
         results['pts_mask_fields'] = []
@@ -98,6 +135,14 @@ class Custom3DDataset(Dataset):
         results['box_mode_3d'] = self.box_mode_3d
 
     def prepare_train_data(self, index):
+        """Training data preparation.
+
+        Args:
+            index (int): Index for accessing the target data.
+
+        Returns:
+            dict: Training data dict corresponding to the index.
+        """
         input_dict = self.get_data_info(index)
         if input_dict is None:
             return None
@@ -109,6 +154,14 @@ class Custom3DDataset(Dataset):
         return example
 
     def prepare_test_data(self, index):
+        """Prepare data for testing.
+
+        Args:
+            index (int): Index for accessing the target data.
+
+        Returns:
+            dict: Testing data dict corresponding to the index.
+        """
         input_dict = self.get_data_info(index)
         self.pre_pipeline(input_dict)
         example = self.pipeline(input_dict)
@@ -145,6 +198,19 @@ class Custom3DDataset(Dataset):
                        outputs,
                        pklfile_prefix=None,
                        submission_prefix=None):
+        """Format the results to pkl file.
+
+        Args:
+            outputs (list[dict]): Testing results of the dataset.
+            pklfile_prefix (str | None): The prefix of pkl files. It includes
+                the file path and the prefix of filename, e.g., "a/b/prefix".
+                If not specified, a temp file will be created. Default: None.
+
+        Returns:
+            tuple: (outputs, tmp_dir), outputs is the detection results,
+                tmp_dir is the temporal directory created for saving json
+                files when jsonfile_prefix is not specified.
+        """
         if pklfile_prefix is None:
             tmp_dir = tempfile.TemporaryDirectory()
             pklfile_prefix = osp.join(tmp_dir.name, 'results')

mmdet3d/datasets/kitti2d_dataset.py

@@ -50,6 +50,14 @@ class Kitti2DDataset(CustomDataset):
     """
 
     def load_annotations(self, ann_file):
+        """Load annotations from ann_file.
+
+        Args:
+            ann_file (str): Path of the annotation file.
+
+        Returns:
+            list[dict]: List of annotations.
+        """
         self.data_infos = mmcv.load(ann_file)
         self.cat2label = {
             cat_name: i
@@ -66,6 +74,18 @@ class Kitti2DDataset(CustomDataset):
         return valid_inds
 
     def get_ann_info(self, index):
+        """Get annotation info according to the given index.
+
+        Args:
+            index (int): Index of the annotation data to get.
+
+        Returns:
+            dict: Standard annotation dictionary
+                consists of the data information.
+
+                - bboxes (np.ndarray): ground truth bboxes
+                - labels (np.ndarray): labels of ground truths
+        """
         # Use index to get the annos, thus the evalhook could also use this api
         info = self.data_infos[index]
         annos = info['annos']
@@ -87,6 +107,15 @@ class Kitti2DDataset(CustomDataset):
         return anns_results
 
     def prepare_train_img(self, idx):
+        """Training image preparation.
+
+        Args:
+            index (int): Index for accessing the target image data.
+
+        Returns:
+            dict: Training image data dict after preprocessing
+                corresponding to the index.
+        """
         img_raw_info = self.data_infos[idx]['image']
         img_info = dict(filename=img_raw_info['image_path'])
         ann_info = self.get_ann_info(idx)
@@ -99,6 +128,15 @@ class Kitti2DDataset(CustomDataset):
         return self.pipeline(results)
 
     def prepare_test_img(self, idx):
+        """Prepare data for testing.
+
+        Args:
+            index (int): Index for accessing the target image data.
+
+        Returns:
+            dict: Testing image data dict after preprocessing
+                corresponding to the index.
+        """
         img_raw_info = self.data_infos[idx]['image']
         img_info = dict(filename=img_raw_info['image_path'])
         results = dict(img_info=img_info)
@@ -108,11 +146,29 @@ class Kitti2DDataset(CustomDataset):
         return self.pipeline(results)
 
     def drop_arrays_by_name(self, gt_names, used_classes):
+        """Drop irrelevant ground truths by name.
+
+        Args:
+            gt_names (list[str]): Names of ground truths.
+            used_classes (list[str]): Classes of interest.
+
+        Returns:
+            np.ndarray: Indices of ground truths that will be dropped.
+        """
         inds = [i for i, x in enumerate(gt_names) if x not in used_classes]
         inds = np.array(inds, dtype=np.int64)
         return inds
 
     def keep_arrays_by_name(self, gt_names, used_classes):
+        """Keep useful ground truths by name.
+
+        Args:
+            gt_names (list[str]): Names of ground truths.
+            used_classes (list[str]): Classes of interest.
+
+        Returns:
+            np.ndarray: Indices of ground truths that will be keeped.
+        """
         inds = [i for i, x in enumerate(gt_names) if x in used_classes]
         inds = np.array(inds, dtype=np.int64)
         return inds
@@ -125,6 +181,17 @@ class Kitti2DDataset(CustomDataset):
         return result_files
 
     def evaluate(self, result_files, eval_types=None):
+        """Evaluation in KITTI protocol.
+
+        Args:
+            result_files (str): Path of result files.
+            eval_types (str): Types of evaluation. Default: None.
+                KITTI dataset only support 'bbox' evaluation type.
+
+        Returns:
+            tuple (str, dict): Average precision results in str format
+                and average precision results in dict format.
+        """
         from mmdet3d.core.evaluation import kitti_eval
         eval_types = ['bbox'] if not eval_types else eval_types
         assert eval_types in ('bbox', ['bbox'

mmdet3d/datasets/kitti_dataset.py

@@ -83,6 +83,23 @@ class KittiDataset(Custom3DDataset):
         return pts_filename
 
     def get_data_info(self, index):
+        """Get data info according to the given index.
+
+        Args:
+            index (int): Index of the sample data to get.
+
+        Returns:
+            dict: Standard input_dict consists of the
+                data information.
+
+                - sample_idx (str): sample index
+                - pts_filename (str): filename of point clouds
+                - img_prefix (str | None): prefix of image files
+                - img_info (dict): image info
+                - lidar2img (list[np.ndarray], optional): transformations from
+                    lidar to different cameras
+                - ann_info (dict): annotation info
+        """
         info = self.data_infos[index]
         sample_idx = info['image']['image_idx']
         img_filename = os.path.join(self.data_root,
@@ -109,6 +126,22 @@ class KittiDataset(Custom3DDataset):
         return input_dict
 
     def get_ann_info(self, index):
+        """Get annotation info according to the given index.
+
+        Args:
+            index (int): Index of the annotation data to get.
+
+        Returns:
+            dict: Standard annotation dictionary
+                consists of the data information.
+
+                - gt_bboxes_3d (:obj:``LiDARInstance3DBoxes``):
+                    3D ground truth bboxes
+                - gt_labels_3d (np.ndarray): labels of ground truths
+                - gt_bboxes (np.ndarray): 2D ground truth bboxes
+                - gt_labels (np.ndarray): labels of ground truths
+                - gt_names (list[str]): class names of ground truths
+        """
         # Use index to get the annos, thus the evalhook could also use this api
         info = self.data_infos[index]
         rect = info['calib']['R0_rect'].astype(np.float32)
@@ -153,16 +186,43 @@ class KittiDataset(Custom3DDataset):
         return anns_results
 
     def drop_arrays_by_name(self, gt_names, used_classes):
+        """Drop irrelevant ground truths by name.
+
+        Args:
+            gt_names (list[str]): Names of ground truths.
+            used_classes (list[str]): Classes of interest.
+
+        Returns:
+            np.ndarray: Indices of ground truths that will be dropped.
+        """
         inds = [i for i, x in enumerate(gt_names) if x not in used_classes]
         inds = np.array(inds, dtype=np.int64)
         return inds
 
     def keep_arrays_by_name(self, gt_names, used_classes):
+        """Keep useful ground truths by name.
+
+        Args:
+            gt_names (list[str]): Names of ground truths.
+            used_classes (list[str]): Classes of interest.
+
+        Returns:
+            np.ndarray: Indices of ground truths that will be keeped.
+        """
         inds = [i for i, x in enumerate(gt_names) if x in used_classes]
         inds = np.array(inds, dtype=np.int64)
         return inds
 
     def remove_dontcare(self, ann_info):
+        """Remove annotations that do not need to be cared.
+
+        Args:
+            ann_info (dict): Dict of annotation infos. The ``'DontCare'``
+                annotations will be removed according to ann_file['name'].
+
+        Returns:
+            dict: Annotations after filtering.
+        """
         img_filtered_annotations = {}
         relevant_annotation_indices = [
             i for i, x in enumerate(ann_info['name']) if x != 'DontCare'
@@ -176,6 +236,23 @@ class KittiDataset(Custom3DDataset):
                        outputs,
                        pklfile_prefix=None,
                        submission_prefix=None):
+        """Format the results to pkl file.
+
+        Args:
+            outputs (list[dict]): Testing results of the dataset.
+            pklfile_prefix (str | None): The prefix of pkl files. It includes
+                the file path and the prefix of filename, e.g., "a/b/prefix".
+                If not specified, a temp file will be created. Default: None.
+            submission_prefix (str | None): The prefix of submitted files. It
+                includes the file path and the prefix of filename, e.g.,
+                "a/b/prefix". If not specified, a temp file will be created.
+                Default: None.
+
+        Returns:
+            tuple: (result_files, tmp_dir), result_files is a dict containing
+                the json filepaths, tmp_dir is the temporal directory created
+                for saving json files when jsonfile_prefix is not specified.
+        """
         if pklfile_prefix is None:
             tmp_dir = tempfile.TemporaryDirectory()
             pklfile_prefix = osp.join(tmp_dir.name, 'results')
@@ -390,7 +467,7 @@ class KittiDataset(Custom3DDataset):
             pklfile_prefix (str | None): The prefix of pkl file.
             submission_prefix (str | None): The prefix of submission file.
 
-        Return:
+        Returns:
             List[dict]: A list of dict have the kitti format
         """
         assert len(net_outputs) == len(self.data_infos)
@@ -553,6 +630,12 @@ class KittiDataset(Custom3DDataset):
             )
 
     def show(self, results, out_dir):
+        """Results visualization.
+
+        Args:
+            results (list[dict]): List of bounding boxes results.
+            out_dir (str): Output directory of visualization result.
+        """
         assert out_dir is not None, 'Expect out_dir, got none.'
         for i, result in enumerate(results):
             example = self.prepare_test_data(i)

mmdet3d/datasets/nuscenes_dataset.py

@@ -139,6 +139,14 @@ class NuScenesDataset(Custom3DDataset):
             )
 
     def load_annotations(self, ann_file):
+        """Load annotations from ann_file.
+
+        Args:
+            ann_file (str): Path of the annotation file.
+
+        Returns:
+            list[dict]: List of annotations sorted by timestamps.
+        """
         data = mmcv.load(ann_file)
         data_infos = list(sorted(data['infos'], key=lambda e: e['timestamp']))
         data_infos = data_infos[::self.load_interval]
@@ -147,6 +155,24 @@ class NuScenesDataset(Custom3DDataset):
         return data_infos
 
     def get_data_info(self, index):
+        """Get data info according to the given index.
+
+        Args:
+            index (int): Index of the sample data to get.
+
+        Returns:
+            dict: Standard input_dict consists of the
+                data information.
+
+                - sample_idx (str): sample index
+                - pts_filename (str): filename of point clouds
+                - sweeps (list[dict]): infos of sweeps
+                - timestamp (float): sample timestamp
+                - img_filename (str, optional): image filename
+                - lidar2img (list[np.ndarray], optional): transformations from
+                    lidar to different cameras
+                - ann_info (dict): annotation info
+        """
         info = self.data_infos[index]
 
         # standard protocal modified from SECOND.Pytorch
@@ -188,6 +214,20 @@ class NuScenesDataset(Custom3DDataset):
         return input_dict
 
     def get_ann_info(self, index):
+        """Get annotation info according to the given index.
+
+        Args:
+            index (int): Index of the annotation data to get.
+
+        Returns:
+            dict: Standard annotation dictionary
+                consists of the data information.
+
+                - gt_bboxes_3d (:obj:``LiDARInstance3DBoxes``):
+                    3D ground truth bboxes
+                - gt_labels_3d (np.ndarray): labels of ground truths
+                - gt_names (list[str]): class names of ground truths
+        """
         info = self.data_infos[index]
         # filter out bbox containing no points
         mask = info['num_lidar_pts'] > 0
@@ -221,6 +261,17 @@ class NuScenesDataset(Custom3DDataset):
         return anns_results
 
     def _format_bbox(self, results, jsonfile_prefix=None):
+        """Convert the results to the standard format.
+
+        Args:
+            results (list[dict]): Testing results of the dataset.
+            jsonfile_prefix (str): The prefix of the output jsonfile.
+                You can specify the output directory/filename by
+                modifying the jsonfile_prefix. Default: None.
+
+        Returns:
+            str: Path of the output json file.
+        """
         nusc_annos = {}
         mapped_class_names = self.CLASSES
 
@@ -283,6 +334,19 @@ class NuScenesDataset(Custom3DDataset):
                          logger=None,
                          metric='bbox',
                          result_name='pts_bbox'):
+        """Evaluation for a single model in nuScenes protocol.
+
+        Args:
+            result_path (str): Path of the result file.
+            logger (logging.Logger | str | None): Logger used for printing
+                related information during evaluation. Default: None.
+            metric (str): Metric name used for evaluation. Default: 'bbox'.
+            result_name (str): Result name in the metric prefix.
+                Default: 'pts_bbox'.
+
+        Returns:
+            dict: Dictionary of evaluation details.
+        """
         from nuscenes import NuScenes
         from nuscenes.eval.detection.evaluate import NuScenesEval
 
@@ -400,6 +464,12 @@ class NuScenesDataset(Custom3DDataset):
         return results_dict
 
     def show(self, results, out_dir):
+        """Results visualization.
+
+        Args:
+            results (list[dict]): List of bounding boxes results.
+            out_dir (str): Output directory of visualization result.
+        """
         for i, result in enumerate(results):
             example = self.prepare_test_data(i)
             points = example['points'][0]._data.numpy()
@@ -421,6 +491,18 @@ class NuScenesDataset(Custom3DDataset):
 
 
 def output_to_nusc_box(detection):
+    """Convert the output to the box class in the nuScenes.
+
+    Args:
+        detection (dict): Detection results.
+
+            - boxes_3d (:obj:``BaseInstance3DBoxes``): detection bbox
+            - scores_3d (torch.Tensor): detection scores
+            - labels_3d (torch.Tensor): predicted box labels
+
+    Returns:
+        list[:obj:``NuScenesBox``]: List of standard NuScenesBoxes.
+    """
     box3d = detection['boxes_3d']
     scores = detection['scores_3d'].numpy()
     labels = detection['labels_3d'].numpy()
@@ -456,6 +538,21 @@ def lidar_nusc_box_to_global(info,
                              classes,
                              eval_configs,
                              eval_version='detection_cvpr_2019'):
+    """Convert the box from ego to global coordinate.
+
+    Args:
+        info (dict): Info for a specific sample data, including the
+            calibration information.
+        boxes (list[:obj:``NuScenesBox``]): List of predicted NuScenesBoxes.
+        classes (list[str]): Mapped classes in the evaluation.
+        eval_configs (object): Evaluation configuration object.
+        eval_version (str): Evaluation version.
+            Default: 'detection_cvpr_2019'
+
+    Returns:
+        list: List of standard NuScenesBoxes in the global
+            coordinate.
+    """
     box_list = []
     for box in boxes:
         # Move box to ego vehicle coord system

mmdet3d/datasets/pipelines/dbsampler.py

@@ -51,6 +51,16 @@ class BatchSampler:
 
 @OBJECTSAMPLERS.register_module()
 class DataBaseSampler(object):
+    """Class for sampling data from the ground truth database.
+
+    Args:
+        info_path (str): Path of groundtruth database info.
+        data_root (str): Path of groundtruth database.
+        rate (float): Rate of actual sampled over maximum sampled number.
+        prepare (dict): Name of preparation functions and the input value.
+        sample_groups (dict): Sampled classes and numbers.
+        classes (list[str]): List of classes. Default: None.
+    """
 
     def __init__(self,
                  info_path,
@@ -104,6 +114,15 @@ class DataBaseSampler(object):
 
     @staticmethod
     def filter_by_difficulty(db_infos, removed_difficulty):
+        """Filter ground truths by difficulties.
+
+        Args:
+            db_infos (dict): Info of groundtruth database.
+            removed_difficulty (list): Difficulties that are not qualified.
+
+        Returns:
+            dict: Info of database after filtering.
+        """
         new_db_infos = {}
         for key, dinfos in db_infos.items():
             new_db_infos[key] = [
@@ -114,6 +133,16 @@ class DataBaseSampler(object):
 
     @staticmethod
     def filter_by_min_points(db_infos, min_gt_points_dict):
+        """Filter ground truths by number of points in the bbox.
+
+        Args:
+            db_infos (dict): Info of groundtruth database.
+            min_gt_points_dict (dict): Different number of minimum points
+                needed for different categories of ground truths.
+
+        Returns:
+            dict: Info of database after filtering.
+        """
         for name, min_num in min_gt_points_dict.items():
             min_num = int(min_num)
             if min_num > 0:
@@ -125,6 +154,22 @@ class DataBaseSampler(object):
         return db_infos
 
     def sample_all(self, gt_bboxes, gt_labels, img=None):
+        """Sampling all categories of bboxes.
+
+        Args:
+            gt_bboxes (np.ndarray): Ground truth bounding boxes.
+            gt_labels (np.ndarray): Labels of boxes.
+
+        Returns:
+            dict: Dict of sampled 'pseudo ground truths'.
+
+                - gt_labels_3d (np.ndarray): labels of ground truths:
+                    labels of sampled ground truths
+                - gt_bboxes_3d (:obj:``BaseInstance3DBoxes``):
+                    sampled 3D bounding boxes
+                - points (np.ndarray): sampled points
+                - group_ids (np.ndarray): ids of sampled ground truths
+        """
         sampled_num_dict = {}
         sample_num_per_class = []
         for class_name, max_sample_num in zip(self.sample_classes,
@@ -198,6 +243,16 @@ class DataBaseSampler(object):
         return ret
 
     def sample_class_v2(self, name, num, gt_bboxes):
+        """Sampling specific categories of bounding boxes.
+
+        Args:
+            name (str): Class of objects to be sampled.
+            num (int): Number of sampled bboxes.
+            gt_bboxes (np.ndarray): Ground truth boxes.
+
+        Returns:
+            list[dict]: Valid samples after collision test.
+        """
         sampled = self.sampler_dict[name].sample(num)
         sampled = copy.deepcopy(sampled)
         num_gt = gt_bboxes.shape[0]

mmdet3d/datasets/pipelines/loading.py

@@ -114,7 +114,7 @@ class PointSegClassMapping(object):
     others as len(valid_cat_ids).
 
     Args:
-        valid_cat_ids (tuple[int): A tuple of valid category.
+        valid_cat_ids (tuple[int]): A tuple of valid category.
     """
 
     def __init__(self, valid_cat_ids):

mmdet3d/datasets/pipelines/transforms_3d.py

@@ -171,12 +171,12 @@ class ObjectNoise(object):
     """Apply noise to each GT objects in the scene.
 
     Args:
-        translation_std (list, optional): Standard deviation of the
+        translation_std (list[float], optional): Standard deviation of the
             distribution where translation noise are sampled from.
             Defaults to [0.25, 0.25, 0.25].
-        global_rot_range (list, optional): Global rotation to the scene.
+        global_rot_range (list[float], optional): Global rotation to the scene.
             Defaults to [0.0, 0.0].
-        rot_range (list, optional): Object rotation range.
+        rot_range (list[float], optional): Object rotation range.
             Defaults to [-0.15707963267, 0.15707963267].
         num_try (int, optional): Number of times to try if the noise applied is
             invalid. Defaults to 100.
@@ -429,8 +429,9 @@ class IndoorPointSample(object):
             return_choices (bool): Whether return choice.
 
         Returns:
-            points (ndarray): 3D Points.
-            choices (ndarray): The generated random samples.
+            tuple (np.ndarray, np.ndarray) | np.ndarray:
+                points (np.ndarray): 3D Points.
+                choices (np.ndarray, optional): The generated random samples.
         """
         if replace is None:
             replace = (points.shape[0] < num_samples)

mmdet3d/datasets/scannet_dataset.py

@@ -64,6 +64,21 @@ class ScanNetDataset(Custom3DDataset):
             test_mode=test_mode)
 
     def get_ann_info(self, index):
+        """Get annotation info according to the given index.
+
+        Args:
+            index (int): Index of the annotation data to get.
+
+        Returns:
+            dict: Standard annotation dictionary
+                consists of the data information.
+
+                - gt_bboxes_3d (:obj:``DepthInstance3DBoxes``):
+                    3D ground truth bboxes
+                - gt_labels_3d (np.ndarray): labels of ground truths
+                - pts_instance_mask_path (str): path of instance masks
+                - pts_semantic_mask_path (str): path of semantic masks
+        """
         # Use index to get the annos, thus the evalhook could also use this api
         info = self.data_infos[index]
         if info['annos']['gt_num'] != 0:
@@ -94,6 +109,12 @@ class ScanNetDataset(Custom3DDataset):
         return anns_results
 
     def show(self, results, out_dir):
+        """Results visualization.
+
+        Args:
+            results (list[dict]): List of bounding boxes results.
+            out_dir (str): Output directory of visualization result.
+        """
         assert out_dir is not None, 'Expect out_dir, got none.'
         for i, result in enumerate(results):
             data_info = self.data_infos[i]

mmdet3d/datasets/sunrgbd_dataset.py

@@ -62,6 +62,21 @@ class SUNRGBDDataset(Custom3DDataset):
             test_mode=test_mode)
 
     def get_ann_info(self, index):
+        """Get annotation info according to the given index.
+
+        Args:
+            index (int): Index of the annotation data to get.
+
+        Returns:
+            dict: Standard annotation dictionary
+                consists of the data information.
+
+                - gt_bboxes_3d (:obj:``DepthInstance3DBoxes``):
+                    3D ground truth bboxes
+                - gt_labels_3d (np.ndarray): labels of ground truths
+                - pts_instance_mask_path (str): path of instance masks
+                - pts_semantic_mask_path (str): path of semantic masks
+        """
         # Use index to get the annos, thus the evalhook could also use this api
         info = self.data_infos[index]
         if info['annos']['gt_num'] != 0:
@@ -81,6 +96,12 @@ class SUNRGBDDataset(Custom3DDataset):
         return anns_results
 
     def show(self, results, out_dir):
+        """Results visualization.
+
+        Args:
+            results (list[dict]): List of bounding boxes results.
+            out_dir (str): Output directory of visualization result.
+        """
         assert out_dir is not None, 'Expect out_dir, got none.'
         for i, result in enumerate(results):
             data_info = self.data_infos[i]