使用Python在给定复杂点数组的情况下生成Vandermonde矩阵
要生成给定阶数的Vandermonde矩阵,可以使用Python Numpy中的polynomial.polyvander()方法。该方法返回Vandermonde矩阵。返回矩阵的shape为x.shape + (deg + 1,),其中最后一个索引是x的幂。dtype与转换后的x相同。
参数a是点数组。可能根据元素是否复杂将其dtype转换为float64或complex128。如果x是标量,则将其转换为1-D数组。参数deg是结果矩阵的阶数。
步骤
首先,导入所需的库−
import numpy as np
from numpy.polynomial.polynomial import polyvander
创建一个数组 −
x = np.array([-2.+2.j, -1.+2.j, 0.+2.j, 1.+2.j, 2.+2.j])
显示数组 –
print("Our Array...\n",x)
检查尺寸 –
print("\nDimensions of our Array...\n",x.ndim)
获取数据类型
print("\nDatatype of our Array object...\n",x.dtype)
获取形状−
print("\nShape of our Array object...\n",x.shape)
要生成给定阶数的范德蒙矩阵,在Python的Numpy中使用polynomial.polyvander()函数进行操作 –
print("\nResult...\n",polyvander(x, 2))
示例
import numpy as np
from numpy.polynomial.polynomial import polyvander
# Create an array
x = np.array([-2.+2.j, -1.+2.j, 0.+2.j, 1.+2.j, 2.+2.j])
# Display the array
print("Our Array...\n",x)
# Check the Dimensions
print("\nDimensions of our Array...\n",x.ndim)
# Get the Datatype
print("\nDatatype of our Array object...\n",x.dtype)
# Get the Shape
print("\nShape of our Array object...\n",x.shape)
# To generate a Vandermonde matrix of given degree, use the polynomial.polyvander() in Python Numpy
print("\nResult...\n",polyvander(x, 2))
输出
Our Array...
[-2.+2.j -1.+2.j 0.+2.j 1.+2.j 2.+2.j]
Dimensions of our Array...
1
Datatype of our Array object...
complex128
Shape of our Array object...
(5,)
Result...
[[ 1.+0.j -2.+2.j 0.-8.j]
[ 1.+0.j -1.+2.j -3.-4.j]
[ 1.+0.j 0.+2.j -4.+0.j]
[ 1.+0.j 1.+2.j -3.+4.j]
[ 1.+0.j 2.+2.j 0.+8.j]]