numpy.polynomial.polynomial.polysub

numpy.polynomial.polynomial.polysub(c1, c2)

Subtract one polynomial from another.

Returns the difference of two polynomials c1 - c2. The arguments are sequences of coefficients from lowest order term to highest, i.e., [1,2,3] represents the polynomial 1 + 2*x + 3*x**2.

Parameters :

c1, c2 : array_like

1-D arrays of polynomial coefficients ordered from low to high.

Returns :

out : ndarray

Of coefficients representing their difference.

See also

polyadd, polymul, polydiv, polypow

Examples

>>> from numpy import polynomial as P
>>> c1 = (1,2,3)
>>> c2 = (3,2,1)
>>> P.polysub(c1,c2)
array([-2.,  0.,  2.])
>>> P.polysub(c2,c1) # -P.polysub(c1,c2)
array([ 2.,  0., -2.])