np.zeros(value.shape, dtype=np.int)
时间: 2023-10-21 12:23:42 浏览: 137
您的问题是关于使用NumPy创建一个与给定数组形状相同的全零数组,并且数据类型为整数。
下面是使用NumPy的`zeros`函数来实现的代码:
```python
import numpy as np
# 假设value是一个已知的数组
zeros_array = np.zeros(value.shape, dtype=np.int)
print(zeros_array)
```
这将创建一个与`value`数组具有相同形状的新数组`zeros_array`,并且其中的所有元素都为零。数据类型通过`dtype`参数设置为`np.int`,这表示数组中的元素将为整数类型。
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:
```python
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 Draw_Classification_Map(label, name: str, scale: float = 4.0, dpi: int = 400): ''' get classification map , then save to given path :param label: classification label, 2D :param name: saving path and file's name :param scale: scale of image. If equals to 1, then saving-size is just the label-size :param dpi: default is OK :return: null ''' fig, ax = plt.subplots() numlabel = np.array(label) v = spy.imshow(classes=numlabel.astype(np.int16), fignum=fig.number) ax.set_axis_off() ax.xaxis.set_visible(False) ax.yaxis.set_visible(False) fig.set_size_inches(label.shape[1] * scale / dpi, label.shape[0] * scale / dpi) foo_fig = plt.gcf() # 'get current figure' plt.gca().xaxis.set_major_locator(plt.NullLocator()) plt.gca().yaxis.set_major_locator(plt.NullLocator()) plt.subplots_adjust(top=1, bottom=0, right=1, left=0, hspace=0, wspace=0) foo_fig.savefig(name + '.png', format='png', transparent=True, dpi=dpi, pad_inches=0) pass怎么才能把这段代码输出的超像素级图片转换为像素级图片
要将超像素级别的图片转换为像素级别的图片,需要进行图像分割的反过程。一种简单的方法是,对于每个超像素,使用超像素中心点的值来填充整个超像素区域。可以使用 OpenCV 中的函数 `watershed` 对图像进行分割,然后对于每个超像素,找到其对应的标签,并使用该标签中心点的像素值填充整个超像素区域。以下是可能实现该方法的代码示例:
```python
import cv2
import numpy as np
# 读取超像素级别的图像
superpixel_image = cv2.imread('superpixel_image.png')
# 读取超像素标签图像
superpixel_labels = cv2.imread('superpixel_labels.png', cv2.IMREAD_GRAYSCALE)
# 对超像素标签图像进行分水岭分割
markers = cv2.watershed(superpixel_image, superpixel_labels)
# 对于每个超像素,找到其对应的标签,并使用该标签中心点的像素值填充整个超像素区域
image = np.zeros_like(superpixel_image)
for label in np.unique(markers):
if label == -1:
continue
mask = np.zeros_like(superpixel_labels)
mask[markers == label] = 255
_, contours, _ = cv2.findContours(mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
if len(contours) == 0:
continue
center = np.mean(contours[0], axis=0, dtype=np.int32)
pixel_value = superpixel_image[center[0], center[1]]
image[markers == label] = pixel_value
# 保存像素级别的图像
cv2.imwrite('pixel_image.png', image)
```
请注意,以上代码示例仅供参考,具体实现可能会因图像分割算法和超像素算法的不同而有所差异。
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