numpy.polymul

numpy.polymul(a1, a2)

Find the product of two polynomials.

備註

這是舊版多項式 API 的一部分。自 1.4 版本起，建議使用 numpy.polynomial 中定義的新版多項式 API。有關差異的概述，請參閱 transition guide。

Finds the polynomial resulting from the multiplication of the two input polynomials. Each input must be either a poly1d object or a 1D sequence of polynomial coefficients, from highest to lowest degree.

參數:

a1, a2類別數組物件或一維多對象

Input polynomials.

回傳值:

outndarray or poly1d object

The polynomial resulting from the multiplication of the inputs. If either inputs is a poly1d object, then the output is also a poly1d object. Otherwise, it is a 1D array of polynomial coefficients from highest to lowest degree.

也參考

poly1d

A one-dimensional polynomial class.

poly, polyadd, polyder, polydiv, polyfit, polyint, polysub, polyval

convolve

Array convolution. Same output as polymul, but has parameter for overlap mode.

範例

Try it in your browser!

>>> import numpy as np
>>> np.polymul([1, 2, 3], [9, 5, 1])
array([ 9, 23, 38, 17,  3])

Using poly1d objects:

>>> p1 = np.poly1d([1, 2, 3])
>>> p2 = np.poly1d([9, 5, 1])
>>> print(p1)
   2
1 x + 2 x + 3
>>> print(p2)
   2
9 x + 5 x + 1
>>> print(np.polymul(p1, p2))
   4      3      2
9 x + 23 x + 38 x + 17 x + 3

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