History of Nodes and weights of Gauss–Legendre quadrature

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compare when who what
2026-09-10 09:20 bmatschke the differential operator is upright; d is not a variable current reviewed
2026-09-05 11:26 bmatschke the completeness note is read as part of a sentence and was a noun phrase with a telegraphic appendix; say which rules are here, what n indexes, and that each is listed in full
2026-09-04 14:24 bmatschke who asked for a table is not a fact about the mathematics; the issue is answered in the issue
2026-09-02 20:36 bmatschke comment (11) said the weights have degree at least 2 from n=4 on, which the rational central weights two rows up contradict, and comment (8) had at most n-1 where n-1 is the floor; link Gauss-Hermite, which is now a table
2026-09-02 18:30 bmatschke an entry comment states a fact about the number; whether a search for it would be informative is a remark about this website
2026-09-02 13:10 bmatschke a comment states a fact about the mathematics; how strong a search hit would be is a remark about this website
2026-09-02 08:43 zeta3 with claude-fable-5-1 audit: the Definition cites and does not link; what P_n is moves to the first comment
2026-09-02 08:38 zeta3 with claude-fable-5-1 Gauss-Legendre nodes and weights for n <= 30: roots of P_n isolated over Q[x], weights in ball arithmetic, every rule checked for its degree of exactness with a control before being sent
2026-09-02 08:38 zeta3 checking that this table can be written to
2026-09-02 08:37 zeta3 with claude-fable-5-1 draft: nodes and weights of Gauss-Legendre quadrature, proposal 1 of BATCH-2026-09-02

What changed between 2026-09-05 11:26 and 2026-09-10 09:20

from line 1 (8 lines, 1 more than before) @@ -1,7 +1,8 @@
 Title: Nodes and weights of Gauss–Legendre quadrature Definition: For $n\geq 1$ the Gauss–Legendre quadrature rule with $n$ points is the-  unique rule $\int_{-1}^{1} f(x)\,dx \approx \sum_{k=1}^{n} w_k f(x_k)$ that is exact-  for every polynomial $f$ of degree at most $2n-1$ CITE{Wiki}. Listed are its nodes-  $x_1<\cdots<x_n$, the roots of the Legendre polynomial $P_n$, and its weights $w_k$.+  unique rule $\int_{-1}^{1} f(x)\,\mathrm{d}x \approx \sum_{k=1}^{n} w_k f(x_k)$+  that is exact for every polynomial $f$ of degree at most $2n-1$ CITE{Wiki}. Listed+  are its nodes $x_1<\cdots<x_n$, the roots of the Legendre polynomial $P_n$, and+  its weights $w_k$. Parameters:   n:
from line 56 (10 lines) @@ -55,10 +56,10 @@
   formula-weights: $w_k=\dfrac{2}{(1-x_k^2)\,P_n'(x_k)^2}=\dfrac{2\,(1-x_k^2)}{n^2\,P_{n-1}(x_k)^2}$     CITE{AS}.-  formula-exactness: $\sum_{k=1}^{n} w_k x_k^m=\int_{-1}^{1}x^m\,dx=\dfrac{1+(-1)^m}{m+1}$+  formula-exactness: $\sum_{k=1}^{n} w_k x_k^m=\int_{-1}^{1}x^m\,\mathrm{d}x=\dfrac{1+(-1)^m}{m+1}$     for $0\leq m\leq 2n-1$, and not for $m=2n$.   formula-symmetry: $x_{n+1-k}=-x_k$, $w_{n+1-k}=w_k$, $w_k>0$ and $\sum_{k=1}^{n}w_k=2$.   formula-central-weight: 'For odd $n$, $x_{(n+1)/2}=0$ and $w_{(n+1)/2}=\dfrac{2}{P_n''(0)^2}=\dfrac{2\,((n-1)!!)^2}{n^2\,((n-2)!!)^2}$:     $2$, $8/9$, $128/225$, $512/1225$, $32768/99225$ for $n=1,3,5,7,9$.'-  formula-lagrange: $w_k=\int_{-1}^{1}\ell_k(x)\,dx$ with $\ell_k(x)=\prod_{j\neq+  formula-lagrange: $w_k=\int_{-1}^{1}\ell_k(x)\,\mathrm{d}x$ with $\ell_k(x)=\prod_{j\neq     k}\frac{x-x_j}{x_k-x_j}$ the Lagrange basis polynomial of the nodes; the same     integrals over HREF{Lagrange_basis_polynomials_for_equally_spaced_nodes}[equally 

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