Kaggle competition: Global Wheat Detection
<SOS> metric: custom metric Kaggle data source: global-wheat-detection<load_from_csv>
!pip install --no-deps '.. /input/timm-package/timm-0.1.26-py3-none-any.whl' > /dev/null
!pip install --no-deps '.. /input/pycocotools/pycocotools-2.0-cp37-cp37m-linux_x86_64.whl' > /dev/null
def read_data(base : os.path.abspath)-> Tuple[pd.DataFrame, pd.DataFrame, pd.DataFrame]:
train = pd.read_csv(os.path.join(base + '/train.csv'), dtype={'time': np.float32, 'signal': np.float32, 'open_channels':np.int8})
 test = pd.read_csv(os.path.join(base + '/test.csv'), dtype={'time': np.float32, 'signal': np.float32})
 sub = pd.read_csv(os.path.join(base + '/sample_submission.csv'), dtype={'time': np.float32})
 return train, test, sub 
<create_dataframe>
def get_valid_transforms() :
return A.Compose([
A.Resize(height=512, width=512, p=1.0),
ToTensorV2(p=1.0),
], p=1.0 )
def batching(df : pd.DataFrame,
batch_size : int,
add_index : Optional[bool]=True)-> pd.DataFrame :
df['batch_'+ str(batch_size)] = df.groupby(df.index//batch_size, sort=False)['signal'].agg(['ngroup'] ).values + 1
df['batch_'+ str(batch_size)] = df['batch_'+ str(batch_size)].astype(np.uint16)
 if add_index:
df['batch_' + str(batch_size)+'_idx'] = df.index -(df['batch_'+ str(batch_size)] * batch_size)
 df['batch_' + str(batch_size)+'_idx'] = df['batch_' + str(batch_size)+'_idx'].astype(np.uint16)
 return df 
<compute_test_metric>
DATA_ROOT_PATH = '.. /input/global-wheat-detection/test'
class DatasetRetriever(Dataset):
def __init__(self, image_ids, transforms=None):
super().__init__()
self.image_ids = image_ids
self.transforms = transforms
def __getitem__(self, index: int):
image_id = self.image_ids[index]
image = cv2.imread(f'{DATA_ROOT_PATH}/{image_id}.jpg', cv2.IMREAD_COLOR)
 image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB ).astype(np.float32)
 image /= 255.0
if self.transforms:
sample = {'image': image}
sample = self.transforms(**sample)
 image = sample['image']
return image, image_id
def __len__(self)-> int:
return self.image_ids.shape[0]
def maddest(d : Union[np.array, pd.Series, List], axis : Optional[int]=None)-> np.array:
return np.mean(np.absolute(d - np.mean(d, axis)) , axis)
<normalization>
dataset = DatasetRetriever(
 image_ids=np.array([path.split('/')[-1][:-4] for path in glob(f'{DATA_ROOT_PATH}/*.jpg')]),
transforms=get_valid_transforms() 
)
 def collate_fn(batch):
return tuple(zip(*batch))
data_loader = DataLoader(
 dataset,
batch_size=2,
shuffle=False,
num_workers=4,
drop_last=False,
collate_fn=collate_fn
)
def denoise_signal(x : Union[np.array, pd.Series],
wavelet : Optional[Text]='db4',
level : Optional[int]=1)-> np.array:
coeff = pywt.wavedec(x, wavelet, mode="per")
 sigma =(1/0.6745)* maddest(coeff[-level])
 uthresh = sigma * np.sqrt(2*np.log(len(x)))
 coeff[1:] =(pywt.threshold(i, value=uthresh, mode='hard')for i in coeff[1:])
 return pywt.waverec(coeff, wavelet, mode='per')
<normalization>
def load_net(checkpoint_path):
config = get_efficientdet_config('tf_efficientdet_d5')
 net = EfficientDet(config, pretrained_backbone=False)
 config.num_classes = 1
config.image_size=512
net.class_net = HeadNet(config, num_outputs=config.num_classes, norm_kwargs=dict(eps=.001, momentum=.01))
checkpoint = torch.load(checkpoint_path)
 net.load_state_dict(checkpoint['model_state_dict'])
 del checkpoint
gc.collect()
net = DetBenchEval(net, config)
 net.eval() ;
return net.cuda()
net = load_net('.. /input/wheat-effdet5-fold0-best-checkpoint/fold0-best-all-states.bin' )
def denoise_signal_simple(x : Union[np.array, pd.Series],
wavelet : Optional[Text]='db4',
level : Optional[int]=1)-> np.array:
coeff = pywt.wavedec(x, wavelet, mode="per")
 uthresh = 10
coeff[1:] =(pywt.threshold(i, value=uthresh, mode='hard')for i in coeff[1:])
 return pywt.waverec(coeff, wavelet, mode='per')
<train_on_grid>
def make_predictions(images, score_threshold=0.22):
images = torch.stack(images ).cuda().float()
predictions = []
with torch.no_grad() :
det = net(images, torch.tensor([1]*images.shape[0] ).float().cuda())
 for i in range(images.shape[0]):
boxes = det[i].detach().cpu().numpy() [:,:4]
scores = det[i].detach().cpu().numpy() [:,4]
indexes = np.where(scores > score_threshold)[0]
boxes = boxes[indexes]
boxes[:, 2] = boxes[:, 2] + boxes[:, 0]
boxes[:, 3] = boxes[:, 3] + boxes[:, 1]
predictions.append({
'boxes': boxes[indexes],
'scores': scores[indexes],
})
 return [predictions]
def run_wbf(predictions, image_index, image_size=512, iou_thr=0.44, skip_box_thr=0.43, weights=None):
boxes = [(prediction[image_index]['boxes']/(image_size-1)).tolist() for prediction in predictions]
scores = [prediction[image_index]['scores'].tolist() for prediction in predictions]
labels = [np.ones(prediction[image_index]['scores'].shape[0] ).tolist() for prediction in predictions]
boxes, scores, labels = weighted_boxes_fusion(boxes, scores, labels, weights=None, iou_thr=iou_thr, skip_box_thr=skip_box_thr)
 boxes = boxes*(image_size-1)
 return boxes, scores, labels
def trend(df : Union[pd.Series, np.array],
abs_values: Optional[bool]=False)-> float:
idx = np.array(range(len(df)))
 if abs_values:
df = np.abs(df)
 lr = LinearRegression()
lr.fit(idx.reshape(-1, 1), df)
 return lr.coef_[0] 
<feature_engineering>
def format_prediction_string(boxes, scores):
pred_strings = []
for j in zip(scores, boxes):
pred_strings.append("{0:.4f} {1} {2} {3} {4}".format(j[0], j[1][0], j[1][1], j[1][2], j[1][3]))
return " ".join(pred_strings )
def change_rate(df : Union[pd.Series, np.array])-> float:
change =(np.diff(df)/ df[:-1])
 change = change[np.nonzero(change)[0]]
change = change[~np.isnan(change)]
change = change[change != -np.inf]
change = change[change != np.inf]
return np.mean(change)
<create_dataframe>
results = []
for images, image_ids in data_loader:
predictions = make_predictions(images)
 for i, image in enumerate(images):
boxes, scores, labels = run_wbf(predictions, image_index=i)
 boxes =(boxes*2 ).astype(np.int32 ).clip(min=0, max=1023)
 image_id = image_ids[i]
boxes[:, 2] = boxes[:, 2] - boxes[:, 0]
boxes[:, 3] = boxes[:, 3] - boxes[:, 1]
result = {
'image_id': image_id,
'PredictionString': format_prediction_string(boxes, scores)
 }
results.append(result )
<feature_engineering><EOS> 
test_df = pd.DataFrame(results, columns=['image_id', 'PredictionString'])
 test_df.to_csv('submission.csv', index=False)
 test_df.head()