numpy answers
Ex. 1.1. x=np.ones([2,3])
Ex. 1.2. x=np.zeros([2,3])
Ex. 1.3. x=np.zeros([2,3])*np.nan
Ex. 1.4. x=np.ones([2,3],dtype='float32')
Ex. 1.5. x=np.random.randn(2,3)
Ex. 1.6. x=np.random.rand(2,3)
Ex. 2.1. np.array([[1,2],[3,4]])*np.array([[1,1],[2,2]])
Ex. 2.2. np.dot(np.array([[1,2],[3,4]]),np.array([[1,1],[2,2]]))
Ex. 2.3. np.array([[1,2],[3,4]])/np.array([[1,1],[2,2]])
Ex. 2.4. np.array([[1,2],[3,4]])/np.array([[1,1],[2,2]],dtype=’float32’)
Ex. 2.5. np.dot(np.array([[1,2],[3,4]]),np.linalg.inv(np.array([[1,2],[3,4]])))
Ex. 3.1. np.sum(x)
Ex. 3.2. np.sum(x,axis=0)
Ex. 3.3. np.sum(x,axis=-1)
Ex. 4.1. x*np.array([2,4])
Ex. 4.2. np.array([2,4]).reshape(2,1)*x