在 Python 中生成切比雪夫多项式的伪范德蒙德矩阵
要生成切比雪夫多项式的伪范德蒙德矩阵,请在 Python NumPy 中使用 chebyshev.chebvander()。此方法返回度数为 deg 且样本点为 (x, y) 的伪范德蒙德矩阵。
参数 x、y 是点坐标数组,都具有相同的形状。数据类型将转换为 float64 或 complex128,具体取决于任何元素是否为复数。标量将转换为一维数组。参数 deg 是形式为 [x_deg, y_deg] 的最大度数列表。
步骤
首先,导入所需的库:
import numpy as np from numpy.polynomial import chebyshev as C
使用 numpy.array() 方法创建具有相同形状的点坐标数组:
x = np.array([1, 2]) y = np.array([3, 4])
显示数组:
print("Array1...\n",x) print("\nArray2...\n",y)
显示数据类型:
print("\nArray1 datatype...\n",x.dtype) print("\nArray2 datatype...\n",y.dtype)
检查两个数组的维度:
print("\nDimensions of Array1...\n",x.ndim) print("\nDimensions of Array2...\n",y.ndim)
检查两个数组的形状:
print("\nShape of Array1...\n",x.shape) print("\nShape of Array2...\n",y.shape)
要生成切比雪夫多项式的伪范德蒙德矩阵,请在 Python 中使用 chebyshev.chebvander():
x_deg, y_deg = 2, 3 print("\nResult...\n",C.chebvander2d(x,y, [x_deg, y_deg]))
示例
import numpy as np from numpy.polynomial import chebyshev as C # Create arrays of point coordinates, all of the same shape using the numpy.array() method x = np.array([1, 2]) y = np.array([3, 4]) # Display the arrays print("Array1...\n",x) print("\nArray2...\n",y) # Display the datatype print("\nArray1 datatype...\n",x.dtype) print("\nArray2 datatype...\n",y.dtype) # Check the Dimensions of both the arrays print("\nDimensions of Array1...\n",x.ndim) print("\nDimensions of Array2...\n",y.ndim) # Check the Shape of both the arrays print("\nShape of Array1...\n",x.shape) print("\nShape of Array2...\n",y.shape) # To generate a pseudo Vandermonde matrix of the Chebyshev polynomial, use the chebyshev.chebvander() in Python Numpy x_deg, y_deg = 2, 3 print("\nResult...\n",C.chebvander2d(x,y, [x_deg, y_deg]))
输出
Array1... [1 2] Array2... [3 4] Array1 datatype... int64 Array2 datatype... int64 Dimensions of Array1... 1 Dimensions of Array2... 1 Shape of Array1... (2,) Shape of Array2... (2,) Result... [[1.000e+00 3.000e+00 1.700e+01 9.900e+01 1.000e+00 3.000e+00 1.700e+01 9.900e+01 1.000e+00 3.000e+00 1.700e+01 9.900e+01] [1.000e+00 4.000e+00 3.100e+01 2.440e+02 2.000e+00 8.000e+00 6.200e+01 4.880e+02 7.000e+00 2.800e+01 2.170e+02 1.708e+03]]
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