def kullback_leibler_divergence(mu1, sigma1, mu2, sigma2):
term1 = np.linalg.slogdet(sigma2)[1] - np.linalg.slogdet(sigma1)[1]
sigma_inv = np.linalg.inv(sigma2)
term2 = np.matrix.trace(np.dot(sigma_inv, sigma1))
tmp = mu2 - mu1
term3 = np.dot(np.transpose(tmp), np.dot(sigma_inv, tmp))
result = 0.5 * (term1 - tmp.shape[0] + term2 + term3)
return result
def _setPortfolioInfo(self):
port_annual_var: float = round(np.dot(self._weights.T, np.dot(self._dataSimpleCovarianceAnnual, self._weights)), 5)
port_annual_volatility: float = round(np.sqrt(port_annual_var), 5)
port_annual_simple_ret: float = round(np.sum(self._stats.SimpleReturnsNan.mean() * self._weights) * 252, 5)
print('Port Ann Ret', str(round(port_annual_var, 5)*100)+'%')
print('Port Ann Volatility/ Risk', str(round(port_annual_volatility, 5)*100)+'%')
print('Port Ann Variance', str(round(port_annual_simple_ret, 5)*100)+'%')
'''
def predict(self, X, Y, X_train, Y_train):
y_pred = np.zeros(len(Y))
for j in range(len(X)):
pr = 0
for i in range(len(X_train)):
pr += self._alphas[i] * np.dot(
X[j], X_train[i]) * Y_train[i] - (
np.dot(self._w, X_train[i]) - Y_train[i])
y_pred[j] = np.sign(pr)
accuracy = accuracy_score(Y, y_pred, normalize=True)
return accuracy
def calNNY(x, vh, wh, gamaH, thetaJ):
bh = calBh(x, vh, gamaH)
beita = np.dot(bh, wh)
# y = list()
# for i in range(len(beita)):
# y.append(sigmoid(beita[i] + thetaJ))
# y = np.array(y)
y = sigmoid(beita[0] + thetaJ)
return y
def calDertaGd(x, y, dataYi, vh, wh, gamaH, thetaJ, yita):
gi = calGi(y, dataYi)
bh = calBh(x, vh, gamaH)
eh = calEh(wh, gi, bh)
dertaWh = yita * gi * bh
dertaThetaj = -yita * gi
dertaVih = yita * np.dot(np.array([x]).T, np.array([eh]))
dertaGameH = -yita * eh
return np.array([dertaWh]).T, dertaThetaj, dertaVih, np.array([dertaGameH])
def tfidf_similarity(s1, s2):
def add_space(s):
return ' '.join(list(s))
# 将字中间加入空格
s1, s2 = add_space(s1), add_space(s2)
# 转化为TF矩阵
cv = TfidfVectorizer(tokenizer=lambda s: s.split())
corpus = [s1, s2]
vectors = cv.fit_transform(corpus).toarray()
# 计算TF系数
return np.dot(vectors[0],
vectors[1]) / (norm(vectors[0]) * norm(vectors[1]))
def _setMatrices(self, portfolio_data: DataFrame, log_ret: DataFrame,
cov_mat: DataFrame):
for i in range(self._threshold):
weight_arr: np.ndarray = np.random.uniform(
size=len(portfolio_data.columns))
weight_arr = weight_arr / np.sum(weight_arr)
# saving weights in the array
self._weight_matrix[i, :] = weight_arr
# Portfolio Returns
annual_weighted_log_ret: float = (
(np.sum(log_ret.mean() * weight_arr)) + 1)**252 - 1
# Saving Portfolio returns
self._annual_weighted_log_return_matrix[
i] = annual_weighted_log_ret
# Saving Portfolio Risk
portfolio_sd: float = np.sqrt(
np.dot(weight_arr.T, np.dot(cov_mat, weight_arr)))
self._risk_matrix[i] = portfolio_sd
# Portfolio Sharpe Ratio
# Assuming 0% Risk Free Rate
sr: float = annual_weighted_log_ret / portfolio_sd
self._sharpe_ratio_matrix[i] = sr
def LFM_grad_desc(self, max_iter, alpha=0.001, lamda=0.002):
self.M = len(self.R)
self.N = len(self.R[0])
# self.P、Q初始值，随机生成
self.P = np.random.rand(self.M, self.K)
self.Q = np.random.rand(self.N, self.K)
self.Q = self.Q.T
# 开始迭代
for step in range(max_iter):
# 对所有的用户u、物品i做遍历，对应的特征向量Pu、Qi梯度下降
for u in range(self.M):
for i in range(self.N):
# 对于每一个大于0的评分，求出预测评分误差
if self.R[u][i] > 0:
eui = np.dot(self.P[u, :], self.Q[:, i]) - self.R[u][i]
# 带入公式，按照梯度下降算法更新当前的Pu和Qi
for k in range(self.K):
self.P[u][k] = self.P[u][k] - alpha * (2 * eui * self.Q[k][i] + 2 * lamda * self.P[u][k])
self.Q[k][i] = self.Q[k][i] - alpha * (2 * eui * self.P[u][k] + 2 * lamda * self.Q[k][i])
# ui遍历完成，所有特征向量更新完成，可以得到P、self.Q，可以计算预测评分矩阵
# 统计损失函数
self.cost = 0
for u in range(self.M):
for i in range(self.N):
if self.R[u][i] > 0:
self.cost += (np.dot(self.P[u, :], self.Q[:, i]) - self.R[u][i]) ** 2
# 正则化项
for k in range(self.K):
self.cost += lamda * (self.P[u][k] ** 2 + self.Q[k][i] ** 2)
# 提前结束迭代
if self.cost < 0.0001:
break
self.predR = self.P.dot(self.Q) # 预测结果（ndarry）
def calBh(x, vh, gamaH):
ah = np.dot(x, vh)
bh = list()
for i in range(len(ah)):
bh.append(sigmoid(ah[i] + gamaH[0, i]))
return np.array(bh)
def linear(x, y):
a = np.dot(x, y)
return a
def pol(x, y, gamma=1, k0=1, degree=3):
return np.power(gamma * np.dot(x, y) + k0, degree)
def feedForwardNetwork(inputs, weights, bias):
relu_v = np.vectorize(relu)
output = relu_v(np.dot(inputs, weights[0]) + bias[0])
return output[-1].tolist().index(max(output[-1].tolist()))