jax.numpy.polymul¶

jax.numpy.polymul(a1, a2, *, trim_leading_zeros=False)[source]¶

Find the product of two polynomials.

LAX-backend implementation of polymul(). Setting trim_leading_zeros=True makes the output match that of numpy. But prevents the function from being able to be used in compiled code.

Original docstring below.

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.

Parameters: a2 (a1,) – Input polynomials.
Returns: out – 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.
Return type: ndarray or poly1d object

See also

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.

Examples

>>> 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