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]]

更新于: 2022-02-28

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