Subtract one Chebyshev series from another. Returns the difference of two Chebyshev series `c1` - `c2`. The sequences of coefficients are from lowest order term to highest, i.e., [1,2,3] represents the series ``T_0 + 2*T_1 + 3*T_2``. Parameters ---------- c1, c2 : arr
(c1, c2)
| 609 | |
| 610 | |
| 611 | def chebsub(c1, c2): |
| 612 | """ |
| 613 | Subtract one Chebyshev series from another. |
| 614 | |
| 615 | Returns the difference of two Chebyshev series `c1` - `c2`. The |
| 616 | sequences of coefficients are from lowest order term to highest, i.e., |
| 617 | [1,2,3] represents the series ``T_0 + 2*T_1 + 3*T_2``. |
| 618 | |
| 619 | Parameters |
| 620 | ---------- |
| 621 | c1, c2 : array_like |
| 622 | 1-D arrays of Chebyshev series coefficients ordered from low to |
| 623 | high. |
| 624 | |
| 625 | Returns |
| 626 | ------- |
| 627 | out : ndarray |
| 628 | Of Chebyshev series coefficients representing their difference. |
| 629 | |
| 630 | See Also |
| 631 | -------- |
| 632 | chebadd, chebmulx, chebmul, chebdiv, chebpow |
| 633 | |
| 634 | Notes |
| 635 | ----- |
| 636 | Unlike multiplication, division, etc., the difference of two Chebyshev |
| 637 | series is a Chebyshev series (without having to "reproject" the result |
| 638 | onto the basis set) so subtraction, just like that of "standard" |
| 639 | polynomials, is simply "component-wise." |
| 640 | |
| 641 | Examples |
| 642 | -------- |
| 643 | >>> from numpy.polynomial import chebyshev as C |
| 644 | >>> c1 = (1,2,3) |
| 645 | >>> c2 = (3,2,1) |
| 646 | >>> C.chebsub(c1,c2) |
| 647 | array([-2., 0., 2.]) |
| 648 | >>> C.chebsub(c2,c1) # -C.chebsub(c1,c2) |
| 649 | array([ 2., 0., -2.]) |
| 650 | |
| 651 | """ |
| 652 | return pu._sub(c1, c2) |
| 653 | |
| 654 | |
| 655 | def chebmulx(c): |