()
| 893 | |
| 894 | @register('quartic', 'biweight') |
| 895 | def quartic_kernel(): |
| 896 | pdf = lambda t: 15/16 * (1.0 - t * t) ** 2 |
| 897 | cdf = lambda t: sumprod((3/16, -5/8, 15/16, 1/2), |
| 898 | (t**5, t**3, t, 1.0)) |
| 899 | invcdf = _newton_raphson(_quartic_invcdf_estimate, f=cdf, f_prime=pdf) |
| 900 | support = 1.0 |
| 901 | return pdf, cdf, invcdf, support |
| 902 | |
| 903 | def _triweight_invcdf_estimate(p): |
| 904 | # A handrolled piecewise approximation. There is no magic here. |
nothing calls this directly
no test coverage detected