assignment-a1: adds add_matrix_vector and avg_color

mmp/a1/tensors.py

@@ -1,10 +1,17 @@
 import torch
+from PIL import Image
+from torchvision.transforms import ToTensor
+
 
 def avg_color(img: torch.Tensor):
-    raise NotImplementedError()
+    result = img.mean(dim=(1, 2)).tolist()
+    return tuple(result)
+
 
 def mask(foreground: torch.Tensor, background: torch.Tensor, mask_tensor: torch.Tensor, threshold: float):
     raise NotImplementedError()
 
+
 def add_matrix_vector(matrix: torch.Tensor, vector: torch.Tensor):
-    raise NotImplementedError()
+    return matrix.add(vector)
+