Raise a polynomial to a power. Returns the polynomial `c` raised to the power `pow`. The argument `c` is a sequence of coefficients ordered from low to high. i.e., [1,2,3] is the series ``1 + 2*x + 3*x**2.`` Parameters ---------- c : array_like 1-D array of array o
(c, pow, maxpower=None)
| 422 | |
| 423 | |
| 424 | def polypow(c, pow, maxpower=None): |
| 425 | """Raise a polynomial to a power. |
| 426 | |
| 427 | Returns the polynomial `c` raised to the power `pow`. The argument |
| 428 | `c` is a sequence of coefficients ordered from low to high. i.e., |
| 429 | [1,2,3] is the series ``1 + 2*x + 3*x**2.`` |
| 430 | |
| 431 | Parameters |
| 432 | ---------- |
| 433 | c : array_like |
| 434 | 1-D array of array of series coefficients ordered from low to |
| 435 | high degree. |
| 436 | pow : integer |
| 437 | Power to which the series will be raised |
| 438 | maxpower : integer, optional |
| 439 | Maximum power allowed. This is mainly to limit growth of the series |
| 440 | to unmanageable size. Default is 16 |
| 441 | |
| 442 | Returns |
| 443 | ------- |
| 444 | coef : ndarray |
| 445 | Power series of power. |
| 446 | |
| 447 | See Also |
| 448 | -------- |
| 449 | polyadd, polysub, polymulx, polymul, polydiv |
| 450 | |
| 451 | Examples |
| 452 | -------- |
| 453 | >>> from numpy.polynomial import polynomial as P |
| 454 | >>> P.polypow([1,2,3], 2) |
| 455 | array([ 1., 4., 10., 12., 9.]) |
| 456 | |
| 457 | """ |
| 458 | # note: this is more efficient than `pu._pow(polymul, c1, c2)`, as it |
| 459 | # avoids calling `as_series` repeatedly |
| 460 | return pu._pow(np.convolve, c, pow, maxpower) |
| 461 | |
| 462 | |
| 463 | def polyder(c, m=1, scl=1, axis=0): |