def d_sigmoid(y):
if purely_relu:
return u.relu_mask(y)
elif purely_linear:
return 1
else:
return y*(1-y)
def d_nonlin(y):
if purely_relu:
return u.relu_mask(y)
elif purely_linear:
return 1
else:
return y * (1 - y)
def d_nonlin(y):
if purely_relu:
return u.relu_mask(y)
elif purely_linear:
return 1
else:
return y*(1-y)
def relu_newton_test():
tf.reset_default_graph()
X0 = np.genfromtxt('data/rotations_relu_X0.csv',
delimiter= ",")
Y0 = np.genfromtxt('data/rotations_relu_Y0.csv',
delimiter= ",")
W0f = v2c_np(np.genfromtxt('data/rotations_relu_W0f.csv',
delimiter= ","))
assert W0f.shape == (8, 1)
fs = np.genfromtxt('data/rotations_relu_fs.csv',
delimiter= ",").astype(np.int32)
n = len(fs)-2 # number of layers
u.check_equal(fs, [4,2,2,2])
def f(i): return fs[i+1] # W[i] has shape f[i] x f[i-1]
dsize = X0.shape[1]
assert f(-1) == dsize
# load W0f and do shape checks (can remove)
W0s = u.unflatten_np(W0f, fs[1:]) # Wf doesn't have first layer (data matrix)
W0s.insert(0, X0)
Wf_holder = tf.placeholder(dtype, shape=W0f.shape)
Wf = tf.Variable(Wf_holder, name="Wf")
Wf_copy = tf.Variable(Wf_holder, name="Wf_copy")
init_dict = {Wf_holder: W0f}
# Create W's
W = u.unflatten(Wf, fs[1:])
X = tf.constant(X0)
Y = tf.constant(Y0)
W.insert(0, X)
for (numpy_W, tf_W) in zip(W0s, W):
u.check_equal(numpy_W.shape, u.fix_shape(tf_W.shape))
# Create A's
# A[1] == X
A = [0]*(n+2)
A[0] = u.Identity(dsize)
for i in range(n+1):
if i == 0:
A[i+1] = X
else:
A[i+1] = tf.nn.relu(tf.matmul(W[i], A[i], name="A"+str(i+1)))
assert W[0].get_shape() == X0.shape
assert A[n+1].get_shape() == X0.shape
assert A[1].get_shape() == X0.shape
err = Y - A[n+1]
loss = tf.reduce_sum(tf.square(err))/(2*dsize)
lr = tf.Variable(1.0, dtype=dtype, name="learning_rate")
# Create B's
B = [0]*(n+1)
B[n] = (-err/dsize)*u.relu_mask(A[n+1])
Bn = [0]*(n+1) # Newton-modified backprop
Bn[n] = u.Identity(f(n))
for i in range(n-1, -1, -1):
B[i] = t(W[i+1]) @ B[i+1]
Bn[i] = t(W[i+1]) @ Bn[i+1]
if i > 0: # there's no relu on first matrix
B[i] = B[i]*u.relu_mask(A[i+1])
# Bn[i] = Bn[i]*u.relu_mask(A[i+1]) wrong shape for relu mask
# Create U's
U = [list(range(n+1)) for _ in range(n+1)]
for bottom in range(n+1):
for top in range(n+1):
if bottom > top:
prod = u.Identity(f(top))
else:
prod = u.Identity(f(bottom-1))
for i in range(bottom, top+1):
prod = prod@t(W[i]) # TODO: exclude cols which don't propagate
U[bottom][top] = prod
# Block i, j gives hessian block between layer i and layer j
blocks = [list(range(n+1)) for _ in range(n+1)]
for i in range(1, n+1):
for j in range(1, n+1):
term1 = kr(A[i] @ t(A[j]), Bn[i] @ t(Bn[j])) / dsize;
if i == j:
term2 = tf.zeros((f(i)*f(i-1), f(i)*f(i-1)), dtype=dtype)
elif i < j:
term2 = kr(A[i] @ t(B[j]), U[i+1][j-1])
else:
term2 = kr(t(U[j+1][i-1]), B[i] @ t(A[j]))
blocks[i][j]=term1 + term2 @ Kmat(f(j), f(j-1))
# remove leftmost blocks (those are with respect to W[0] which is input)
del blocks[0]
for row in blocks:
del row[0]
hess = u.concat_blocks(blocks)
ihess = u.pseudo_inverse(hess)
sess = tf.Session()
sess.run(tf.global_variables_initializer(), feed_dict=init_dict)
expected_hess = np.loadtxt("data/rotations_relu_newton_hess0.csv",
delimiter= ",")
observed_hess = sess.run(hess)
np.savetxt("data/rotations_relu_newton_hess1.csv", observed_hess,
fmt="%.10f", delimiter=',')
expected_ihess = np.loadtxt("data/rotations_simple_newton_ihess0.csv",
delimiter= ",")
observed_ihess = sess.run(ihess)
u.check_equal(expected_hess, observed_hess)
# create dW's
dW = [0]*(n+1)
for i in range(n+1):
dW[i] = tf.matmul(B[i], tf.transpose(A[i]), name="dW"+str(i))
del dW[0] # get rid of W[0] update
dWf = tf.concat([u.vec(dWi) for dWi in dW], axis=0)
Wf_new = Wf - lr * ihess @ dWf
train_op1 = Wf_copy.assign(Wf_new)
train_op2 = Wf.assign(Wf_copy)
expected_losses = np.loadtxt("data/rotations_simple_newton_losses.csv",
delimiter= ",")
observed_losses = []
# from accompanying notebook
# 0.0111498, 0.0308658, 0.00462571, 0.0000251229, 1.38508*10^-9,
# 1.32383*10^-17, 2.39119*10^-31
for i in range(10):
observed_losses.append(sess.run([loss])[0])
sess.run(train_op1)
sess.run(train_op2)
u.check_equal(observed_losses, expected_losses)
def relu_gradient_test():
tf.reset_default_graph()
X0 = np.genfromtxt('data/rotations_X0.csv',
delimiter= ",")
Y0 = np.genfromtxt('data/rotations_Y0.csv',
delimiter= ",")
W0f = v2c_np(np.genfromtxt('data/rotations_W0f.csv',
delimiter= ","))
assert W0f.shape == (8, 1)
fs = np.genfromtxt('data/rotations_relu_fs.csv',
delimiter= ",").astype(np.int32)
n = len(fs)-2 # number of layers
u.check_equal(fs, [4,2,2,2])
def f(i): return fs[i+1] # W[i] has shape f[i] x f[i-1]
dsize = X0.shape[1]
assert f(-1) == dsize
# load W0f and do shape checks (can remove)
W0s = u.unflatten_np(W0f, fs[1:]) # Wf doesn't have first layer (data matrix)
W0s.insert(0, X0)
Wf_holder = tf.placeholder(dtype, shape=W0f.shape)
Wf = tf.Variable(Wf_holder, name="Wf")
Wf_copy = tf.Variable(Wf_holder, name="Wf_copy")
init_dict = {Wf_holder: W0f}
# Create W's
W = u.unflatten(Wf, fs[1:])
X = tf.constant(X0, name="X0")
Y = tf.constant(Y0, name="Y0")
W.insert(0, X)
for (numpy_W, tf_W) in zip(W0s, W):
u.check_equal(numpy_W.shape, u.fix_shape(tf_W.shape))
# Create A's
# A[1] == X
A = [0]*(n+2)
A[0] = u.Identity(dsize)
for i in range(n+1):
if i == 0:
A[i+1] = X
else:
A[i+1] = tf.nn.relu(tf.matmul(W[i], A[i], name="A"+str(i+1)))
assert W[0].get_shape() == X0.shape
assert A[n+1].get_shape() == X0.shape
assert A[1].get_shape() == X0.shape
err = Y - A[n+1]
loss = tf.reduce_sum(tf.square(err))/(2*dsize)
lr = tf.Variable(0.1, dtype=dtype)
# Create B's
B = [0]*(n+1)
B[n] = (-err/dsize)*u.relu_mask(A[n+1])
for i in range(n-1, -1, -1):
B[i] = t(W[i+1]) @ B[i+1]
if i > 0: # there's no relu on first matrix
B[i] = B[i]*u.relu_mask(A[i+1])
# create dW's
dW = [0]*(n+1)
for i in range(n+1):
dW[i] = tf.matmul(B[i], tf.transpose(A[i]), name="dW"+str(i))
del dW[0] # get rid of W[0] update
dWf = tf.concat([u.vec(dWi) for dWi in dW], axis=0)
Wf_new = Wf - lr * dWf
train_op1 = Wf_copy.assign(Wf_new)
train_op2 = Wf.assign(Wf_copy)
sess = tf.Session()
sess.run(tf.global_variables_initializer(), feed_dict=init_dict)
expected_losses = np.loadtxt("data/rotations_relu_gradient_losses.csv",
delimiter= ",")
observed_losses = []
# From accompanying notebook
# {0.407751, 0.0683822, 0.0138657, 0.0039221, 0.00203637, 0.00164892,
# 0.00156137, 0.00153857, 0.00153051, 0.00152593}
for i in range(10):
observed_losses.append(sess.run([loss])[0])
sess.run(train_op1)
sess.run(train_op2)
u.check_equal(observed_losses, expected_losses)
