diff options
Diffstat (limited to 'numpy/polynomial/polynomial.py')
| -rw-r--r-- | numpy/polynomial/polynomial.py | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/numpy/polynomial/polynomial.py b/numpy/polynomial/polynomial.py index 1baa7d870..d8a032068 100644 --- a/numpy/polynomial/polynomial.py +++ b/numpy/polynomial/polynomial.py @@ -156,7 +156,7 @@ def polyfromroots(roots): .. math:: p(x) = (x - r_0) * (x - r_1) * ... * (x - r_n), - where the `r_n` are the roots specified in `roots`. If a zero has + where the ``r_n`` are the roots specified in `roots`. If a zero has multiplicity n, then it must appear in `roots` n times. For instance, if 2 is a root of multiplicity three and 3 is a root of multiplicity 2, then `roots` looks something like [2, 2, 2, 3, 3]. The roots can appear @@ -192,11 +192,11 @@ def polyfromroots(roots): Notes ----- The coefficients are determined by multiplying together linear factors - of the form `(x - r_i)`, i.e. + of the form ``(x - r_i)``, i.e. .. math:: p(x) = (x - r_0) (x - r_1) ... (x - r_n) - where ``n == len(roots) - 1``; note that this implies that `1` is always + where ``n == len(roots) - 1``; note that this implies that ``1`` is always returned for :math:`a_n`. Examples @@ -1252,10 +1252,11 @@ def polyfit(x, y, deg, rcond=None, full=False, w=None): diagnostic information from the singular value decomposition (used to solve the fit's matrix equation) is also returned. w : array_like, shape (`M`,), optional - Weights. If not None, the contribution of each point - ``(x[i],y[i])`` to the fit is weighted by `w[i]`. Ideally the - weights are chosen so that the errors of the products ``w[i]*y[i]`` - all have the same variance. The default value is None. + Weights. If not None, the weight ``w[i]`` applies to the unsquared + residual ``y[i] - y_hat[i]`` at ``x[i]``. Ideally the weights are + chosen so that the errors of the products ``w[i]*y[i]`` all have the + same variance. When using inverse-variance weighting, use + ``w[i] = 1/sigma(y[i])``. The default value is None. .. versionadded:: 1.5.0 |