linalg.inv(matrix_1) for j in range(N-1,-1,-1): #隐式也是时间倒推循环,区别在于隐式是要解方程组 # 准备好解方程组 M_1 * fj = M_2 * fj+1 + b_1 # Z是对边界条件的处理 Z = np.zeros_like(V_grid[1:M,j + 1]) Z[0] = aj(1) * (V_grid[0,j] + V_grid[0,j+1...
window_size=9) coordinates_warped_subpix = corner_subpix(image_warped_gray, coordinates_warped, window_size=9) def gaussian_weights(window_ext, sigma=1): y, x = np.mgrid[-window_ext:window_ext+1, -window_ext:window_ext+1] g_w = np.zeros(y.shape, dtype = np.double) g_w[:] ...
isMe=1 担任《Mechanical System and Signal Processing》《中国电机工程学报》等期刊审稿专家,擅长领域:信号滤波/降噪,机器学习/深度学习,时间序列预分析/预测,设备故障诊断/缺陷检测/异常检测。
classPCA():"""主成份分析算法 PCA,非监督学习算法."""def__init__(self):self.eigen_values =Noneself.eigen_vectors =Noneself.k =2 deftransform(self, X):"""将原始数据集 X 通过 PCA 进行降维"""covariance = calcu...
Thenumpy.zeros()function is a built-in NumPy Python routine that generates a new array of a specified size, filled with zeros. This is particularly useful in situations where we need to initialize an array in Python with a default value of zero before filling it with more meaningful data. ...
cols]# convert to matrices and initialize thetaX2 = np.matrix(X2.values)y2 = np.matrix(y2.values)theta2 = np.matrix(np.array([0,0,0]))# perform linear regression on the data setg2, cost2 = gradientDescent(X2, y2, theta2, alpha, iters)# get the cost (error) of the model...
def initialize_parameters(n_x, n_h, n_y): np.random.seed(2) # we set up a seed so that our output matches ours although the initialization is random. W1 = np.random.randn(n_h, n_x) * 0.01 #weight matrix of shape (n_h, n_x) ...
本章将构建两种树:第一种是第2节的回归树(regression tree),其每个叶节点包含单个值;第二种是第3节的模型树(model tree),其每个叶节点包含一个线性方程。创建这两种树时,我们将尽量使得代码之间可以重用。下面先给出两种树构建算法中的一些共用代码。
transition_matrix=pd.DataFrame(np.zeros((n, n)), index=unique_states, columns=unique_states) for i in range(len(states) -1): current_state=states.iloc[i] next_state=states.iloc[i+1] transition_matrix.loc[current_state, next_state] +=1 # 归一化 transition_matrix= transition_matrix.div...
1869 Longer Contiguous Segments of Ones than Zeros C++ Python O(n) O(1) Easy 1878 Get Biggest Three Rhombus Sums in a Grid C++ Python O(m * n * min(m, n)) O(m * n) Easy 1886 Determine Whether Matrix Can Be Obtained By Rotation C++ Python O(m * n) O(1) Easy 1895 Lar...