+
+def data_rectangle(nb):
+ x = torch.rand(nb, 1) - 0.5
+ y = torch.rand(nb, 1) * 2 - 1
+ data = torch.cat((y, x), 1)
+ alpha = math.pi / 8
+ data = data @ torch.tensor(
+ [[math.cos(alpha), math.sin(alpha)], [-math.sin(alpha), math.cos(alpha)]]
+ )
+ return data, "rectangle"
+
+