class GumbelMF(nn.Module):
def __init__(self,
n_users,
n_items,
n_dim,
n_obs,
lub=1.,
lib=1.,
luv=1.,
liv=1.,
tau=0.8,
loss=nn.MSELoss):
super(GumbelMF, self).__init__()
self.embed_user = BiasedEmbedding(n_users, n_dim, lb=lub, lv=luv)
self.embed_item = BiasedEmbedding(n_items, n_dim, lb=lib, lv=liv)
self.glob_bias = Parameter(torch.FloatTensor([0.01]))
self.n_obs = n_obs
self.lossf = loss()
self.tau = tau
def forward(self, u, i):
u, i = u.squeeze(), i.squeeze()
bias = self.glob_bias.expand(len(u), 1).squeeze()
bu, lu = self.embed_user(u)
bi, li = self.embed_item(i)
if self.training:
du, di = gumbel_softmax_correlated(lu, li)
# du = gumbel_softmax(lu, self.tau)
# di = gumbel_softmax(li, self.tau)
else:
du = F.softmax(lu)
di = F.softmax(li)
intx = hellinger(du, di)
logodds = (bias + bi + bu + intx).squeeze()
return logodds
def loss(self, prediction, target):
# average likelihood loss per example
ex_llh = self.lossf(prediction, target)
# regularization penalty summed over whole model
epoch_reg = (self.embed_user.prior() + self.embed_item.prior())
# penalty should be computer for a single example
ex_reg = epoch_reg * 1.0 / self.n_obs
return ex_llh + ex_reg
class MF(nn.Module):
def __init__(self,
n_users,
n_items,
n_dim,
n_obs,
lub=1.,
lib=1.,
luv=1.,
liv=1.,
loss=nn.MSELoss):
super(MF, self).__init__()
self.embed_user = BiasedEmbedding(n_users, n_dim, lb=lub, lv=luv)
self.embed_item = BiasedEmbedding(n_items, n_dim, lb=lib, lv=liv)
self.glob_bias = Parameter(torch.FloatTensor([0.01]))
self.n_obs = n_obs
self.lossf = loss()
def forward(self, u, i):
u, i = u.squeeze(), i.squeeze()
bias = self.glob_bias.expand(len(u), 1).squeeze()
bu, vu = self.embed_user(u)
bi, vi = self.embed_item(i)
intx = (vu * vi).sum(dim=1)
logodds = (bias + bi + bu + intx).squeeze()
return logodds
def loss(self, prediction, target):
# average likelihood loss per example
ex_llh = self.lossf(prediction, target)
if self.training:
# regularization penalty summed over whole model
epoch_reg = (self.embed_user.prior() + self.embed_item.prior())
# penalty should be computer for a single example
ex_reg = epoch_reg * 1.0 / self.n_obs
else:
ex_reg = 0.0
return ex_llh + ex_reg
class MFPoly2(nn.Module):
def __init__(self, n_users, n_items, n_dim, n_obs, lub=1.,
lib=1., luv=1., liv=1., loss=nn.MSELoss):
super(MFPoly2, self).__init__()
self.embed_user = BiasedEmbedding(n_users, n_dim, lb=lub, lv=luv)
self.embed_item = BiasedEmbedding(n_items, n_dim, lb=lib, lv=liv)
self.glob_bias = Parameter(torch.FloatTensor([0.01]))
# maps from a scalar (dim=2) of frame and frame^2
# effectively fitting a quadratic polynomial to the frame number
# to a scalar log odds (dim=1)
self.poly = nn.Linear(2, 1)
self.n_obs = n_obs
self.lossf = loss()
def forward(self, u, i, f):
u, i = u.squeeze(), i.squeeze()
bias = self.glob_bias.expand(len(u), 1).squeeze()
bu, vu = self.embed_user(u)
bi, vi = self.embed_item(i)
intx = (vu * vi).sum(dim=1)
frame = [f.unsqueeze(0), f.unsqueeze(0)**2.0]
effect = self.poly(torch.t(torch.log(torch.cat(frame)))).squeeze()
logodds = (bias + bi + bu + intx + effect).squeeze()
return logodds
def loss(self, prediction, target):
# average likelihood loss per example
ex_llh = self.lossf(prediction, target)
if self.training:
# regularization penalty summed over whole model
epoch_reg = (self.embed_user.prior() + self.embed_item.prior())
# penalty should be computer for a single example
ex_reg = epoch_reg * 1.0 / self.n_obs
else:
ex_reg = 0.0
return ex_llh + ex_reg
class FM(nn.Module):
def __init__(self,
n_features,
n_dim,
n_obs,
lb=1.,
lv=1.,
loss=nn.MSELoss):
super(FM, self).__init__()
self.embed_feat = BiasedEmbedding(n_features, n_dim, lb=lb, lv=lv)
self.glob_bias = Parameter(torch.FloatTensor([0.01]))
self.n_obs = n_obs
self.lb = lb
self.lv = lv
self.lossf = loss()
def forward(self, idx):
biases = index_into(self.embed_feat.bias.weight, idx).squeeze()
vectrs = index_into(self.embed_feat.vect.weight, idx)
active = (idx > 0).type(type(biases.data))
biases = (biases * active).sum(dim=1)
vector = factorization_machine(vectrs * active.unsqueeze(2)).sum(dim=1)
logodds = biases + vector
return logodds
def loss(self, prediction, target):
# average likelihood loss per example
ex_llh = self.lossf(prediction, target)
if self.training:
# regularization penalty summed over whole model
epoch_reg = self.embed_feat.prior()
# penalty should be computer for a single example
ex_reg = epoch_reg * 1.0 / self.n_obs
else:
ex_reg = 0.0
return ex_llh + ex_reg