centers = np.reshape(centers, (-1, 2))

这行代码使用了NumPy库中的reshape函数，将centers数组从原本的一维数组转换为二维数组，维度为(-1, 2)。其中-1表示自动计算该维度大小，2表示该维度大小为2。这里的目的是将原本的一维数组中每两个元素作为一个二维坐标点的x和y坐标，转换为二维数组中的每一行表示一个二维坐标点，第一列为x坐标，第二列为y坐标。

相关问题

翻译这段程序并自行赋值调用：import matplotlib.pyplot as plt import numpy as np import sklearn import sklearn.datasets import sklearn.linear_model def plot_decision_boundary(model, X, y): # Set min and max values and give it some padding x_min, x_max = X[0, :].min() - 1, X[0, :].max() + 1 y_min, y_max = X[1, :].min() - 1, X[1, :].max() + 1 h = 0.01 # Generate a grid of points with distance h between them xx, yy = np.meshgrid(np.arange(x_min, x_max, h), np.arange(y_min, y_max, h)) # Predict the function value for the whole grid Z = model(np.c_[xx.ravel(), yy.ravel()]) Z = Z.reshape(xx.shape) # Plot the contour and training examples plt.contourf(xx, yy, Z, cmap=plt.cm.Spectral) plt.ylabel('x2') plt.xlabel('x1') plt.scatter(X[0, :], X[1, :], c=y, cmap=plt.cm.Spectral) def sigmoid(x): s = 1/(1+np.exp(-x)) return s def load_planar_dataset(): np.random.seed(1) m = 400 # number of examples N = int(m/2) # number of points per class print(np.random.randn(N)) D = 2 # dimensionality X = np.zeros((m,D)) # data matrix where each row is a single example Y = np.zeros((m,1), dtype='uint8') # labels vector (0 for red, 1 for blue) a = 4 # maximum ray of the flower for j in range(2): ix = range(Nj,N(j+1)) t = np.linspace(j3.12,(j+1)3.12,N) + np.random.randn(N)0.2 # theta r = anp.sin(4t) + np.random.randn(N)0.2 # radius X[ix] = np.c_[rnp.sin(t), rnp.cos(t)] Y[ix] = j X = X.T Y = Y.T return X, Y def load_extra_datasets(): N = 200 noisy_circles = sklearn.datasets.make_circles(n_samples=N, factor=.5, noise=.3) noisy_moons = sklearn.datasets.make_moons(n_samples=N, noise=.2) blobs = sklearn.datasets.make_blobs(n_samples=N, random_state=5, n_features=2, centers=6) gaussian_quantiles = sklearn.datasets.make_gaussian_quantiles(mean=None, cov=0.5, n_samples=N, n_features=2, n_classes=2, shuffle=True, random_state=None) no_structure = np.random.rand(N, 2), np.random.rand(N, 2) return noisy_circles, noisy_moons, blobs, gaussian_quantiles, no_structure

这段程序是一个分类模型的辅助函数，包括了绘制决策边界、sigmoid函数和加载数据集的函数。具体实现如下：

import matplotlib.pyplot as plt
import numpy as np
import sklearn
import sklearn.datasets
import sklearn.linear_model

def plot_decision_boundary(model, X, y):
    # 设置最小值和最大值，并给它们一些填充
    x_min, x_max = X[0, :].min() - 1, X[0, :].max() + 1
    y_min, y_max = X[1, :].min() - 1, X[1, :].max() + 1
    h = 0.01

    # 生成一个网格，网格中点的距离为h
    xx, yy = np.meshgrid(np.arange(x_min, x_max, h), np.arange(y_min, y_max, h))

    # 对整个网格预测函数值
    Z = model(np.c_[xx.ravel(), yy.ravel()])
    Z = Z.reshape(xx.shape)

    # 绘制轮廓和训练样本
    plt.contourf(xx, yy, Z, cmap=plt.cm.Spectral)
    plt.ylabel('x2')
    plt.xlabel('x1')
    plt.scatter(X[0, :], X[1, :], c=y, cmap=plt.cm.Spectral)

def sigmoid(x):
    s = 1 / (1 + np.exp(-x))
    return s

def load_planar_dataset():
    np.random.seed(1)
    m = 400  # 样本数量
    N = int(m / 2)  # 每个类的样本数量

    # 生成数据集
    D = 2  # 特征维度
    X = np.zeros((m, D))  # 特征矩阵
    Y = np.zeros((m, 1), dtype='uint8')  # 标签向量

    a = 4  # 花的最大半径

    for j in range(2):
        ix = range(N*j, N*(j+1))
        t = np.linspace(j*3.12, (j+1)*3.12, N) + np.random.randn(N)*0.2  # theta
        r = a*np.sin(4*t) + np.random.randn(N)*0.2  # radius
        X[ix] = np.c_[r*np.sin(t), r*np.cos(t)]
        Y[ix] = j

    X = X.T
    Y = Y.T

    return X, Y

def load_extra_datasets():
    N = 200
    noisy_circles = sklearn.datasets.make_circles(n_samples=N, factor=.5, noise=.3)
    noisy_moons = sklearn.datasets.make_moons(n_samples=N, noise=.2)
    blobs = sklearn.datasets.make_blobs(n_samples=N, random_state=5, n_features=2, centers=6)
    gaussian_quantiles = sklearn.datasets.make_gaussian_quantiles(mean=None, cov=0.5, n_samples=N, n_features=2, n_classes=2, shuffle=True, random_state=None)
    no_structure = np.random.rand(N, 2), np.random.rand(N, 2)

    return noisy_circles, noisy_moons, blobs, gaussian_quantiles, no_structure

这段程序中包含了以下函数：

- `plot_decision_boundary(model, X, y)`：绘制分类模型的决策边界，其中`model`是分类模型，`X`是特征矩阵，`y`是标签向量。
- `sigmoid(x)`：实现sigmoid函数。
- `load_planar_dataset()`：加载一个二维的花瓣数据集。
- `load_extra_datasets()`：加载五个其他数据集。

def __init__(self, n_inputs, n_rules, learning_rate=0.01): self.n = n_inputs self.m = n_rules self.lr = learning_rate # Initialize MF parameters using k-means clustering kmeans = KMeans(n_clusters=self.m) x0 = np.random.rand(100, self.n) # 用于聚类的样本点 kmeans.fit(x0) centroids = kmeans.cluster_centers_ # 获取聚类中心 sigmas = np.ones(self.m) * (kmeans.inertia_ / self.m) ** 0.5 # 计算标准差 self.params = { "mf_params": np.concatenate([centroids.flatten(), sigmas.flatten()]), "out_params": np.random.rand((self.n + 1) * self.m, ) } def gaussmf(self, x, c, sigma): return np.exp(-np.power(x - c, 2.) / (2 * np.power(sigma, 2.))) def predict(self, X): mf_out = np.zeros((len(X), self.n, self.m)) for i in range(self.n): mf_out[:, i, :] = self.gaussmf(X[:, i].reshape(-1, 1), self.params['mf_params'][:self.m], self.params['mf_params'][self.m:])出现 operands could not be broadcast together with shapes (32,3) (0,) 修改

根据你提供的代码，我发现在predict函数中，如果X的shape是(32, 3)，则会出现operands could not be broadcast together with shapes (32,3) (0,)的错误。这是因为在计算mf_out时，对于每个输入X[:, i].reshape(-1, 1)，都需要对self.params['mf_params'][:self.m]和self.params['mf_params'][self.m:]进行高斯函数计算，而这两个数组的shape都是(0,)，无法与X[:, i].reshape(-1, 1)进行broadcast。

一种可能的修正方法是，在初始化函数__init__中，将标准差sigmas的shape从(3,)修改为(1, 3)，即：

sigmas = np.ones((1, self.m)) * (kmeans.inertia_ / self.m) ** 0.5

这样，在predict函数中计算高斯函数时，就可以使用np.tile函数将self.params['mf_params'][self.m:]沿着第0维复制32次，使其与X[:, i].reshape(-1, 1)的shape相同：

def predict(self, X):
    mf_out = np.zeros((len(X), self.n, self.m))
    for i in range(self.n):
        sigma = np.tile(self.params['mf_params'][self.m:], (len(X), 1))
        mf_out[:, i, :] = self.gaussmf(X[:, i].reshape(-1, 1), self.params['mf_params'][:self.m], sigma)

这样，就可以避免operands could not be broadcast together with shapes的错误。