What line function should the Unit0 has? I thought it should be 1.22X0+0.6X1 +1.59 = 0, but then the point on the y axis should be (0, -2.65) instead of some positive number as shown in the screenshot.
It’s not a 2D line plot.
You can tell because the horizontal and vertical axes are both feature values (x0 and x1), and the y_hat value is on the Z-axis (protruding out of the surface of your display.
It’s a 3D plot where the Z axis is the y_hat value, and the boundary curve is drawn where y_hat equals 0.5.
Ah I see. Then why the boundary curve is drawn where y_hat equals 0.5 instead of 0 since the Relu is max (0, y_hat)?
Good point, a ReLU unit doesn’t use any threshold value, because ReLU is only used in hidden layers, not in the output.
So I’ll have to think about that a bit further.