Generator

What a reciprocal pairing is worth: three ways to the small half of a palindromic spectrum

One function in the palindromic library, called 7 times across 2 essays. Below: what it draws at its defaults, what it draws at every value an essay asks for, the 14 claims it put to the test while drawing them, and where it stands against the rule this site is named for.

At its defaults it draws what a reciprocal pairing is worth: three ways to the small half of a palindromic spectrum. A palindromic quadratic of size 6 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 5.52·10⁻¹⁵ at every stop and the small ones to 1.041·10⁻⁷ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 4.89·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 6.538·10⁻⁶, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.

pairing-use is one function in lib/figures/palindromic.js — reciprocal pairs — a symmetry the solver discards, and the division that is worth seven orders. Everything below came out of it during this build, at arguments taken from the essays rather than invented for this page. A figure here is the figure a reader meets in an essay, and if the generator changes, this page changes with it.

At its defaults

Drawn even though every essay passes arguments — which on this site is every essay, at 100% of placements since the standard pass. A default nothing exercises is a trap for the next essay to call this with none, and this is the page where a default that has drifted from the figures around it becomes visible.

What a reciprocal pairing is worth: three ways to the small half of a palindromic spectrumA palindromic quadratic of size 6 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 5.52·10⁻¹⁵ at every stop and the small ones to 1.041·10⁻⁷ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 4.89·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 6.538·10⁻⁶, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.1357910⁻¹⁶10⁻¹³10⁻¹⁰10⁻⁷10⁻⁴log₁₀ b, the couplingrelative errorsmall half, directstructure-preservingsmall half, by 1/λone divisionlarge half, direct5.5·10⁻¹⁵small half, direct10⁻⁷small half, by 1/λ4.9·10⁻¹⁵structure-preserving6.5·10⁻⁶the structure is not decorationit is where half the accuracy is

A palindromic quadratic of size 6 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 5.52·10⁻¹⁵ at every stop and the small ones to 1.041·10⁻⁷ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 4.89·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 6.538·10⁻⁶, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.

n: 6

The arguments are the ones A perturbation that keeps the symmetry passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

What a reciprocal pairing is worth: three ways to the small half of a palindromic spectrumA palindromic quadratic of size 6 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 5.52·10⁻¹⁵ at every stop and the small ones to 1.041·10⁻⁷ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 4.89·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 6.538·10⁻⁶, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.1357910⁻¹⁶10⁻¹³10⁻¹⁰10⁻⁷10⁻⁴log₁₀ b, the couplingrelative errorsmall half, directstructure-preservingsmall half, by 1/λone divisionlarge half, direct5.5·10⁻¹⁵small half, direct10⁻⁷small half, by 1/λ4.9·10⁻¹⁵structure-preserving6.5·10⁻⁶the structure is not decorationit is where half the accuracy is

A palindromic quadratic of size 6 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 5.52·10⁻¹⁵ at every stop and the small ones to 1.041·10⁻⁷ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 4.89·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 6.538·10⁻⁶, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.

n: 3

The arguments are the ones A perturbation that keeps the symmetry passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

What a reciprocal pairing is worth: three ways to the small half of a palindromic spectrumA palindromic quadratic of size 3 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 2.54·10⁻¹⁵ at every stop and the small ones to 3.242·10⁻¹³ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 2.62·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 5.871·10⁻⁷, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.1357910⁻¹⁶10⁻¹³10⁻¹⁰10⁻⁷10⁻⁴log₁₀ b, the couplingrelative errorsmall half, directstructure-preservingsmall half, by 1/λone divisionlarge half, direct2.5·10⁻¹⁵small half, direct3.2·10⁻¹³small half, by 1/λ2.6·10⁻¹⁵structure-preserving5.9·10⁻⁷the structure is not decorationit is where half the accuracy is

A palindromic quadratic of size 3 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 2.54·10⁻¹⁵ at every stop and the small ones to 3.242·10⁻¹³ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 2.62·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 5.871·10⁻⁷, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.

n: 4

The arguments are the ones A perturbation that keeps the symmetry passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

What a reciprocal pairing is worth: three ways to the small half of a palindromic spectrumA palindromic quadratic of size 4 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 3.46·10⁻¹⁵ at every stop and the small ones to 1.626·10⁻¹¹ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 1.56·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 3.473·10⁻⁶, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.1357910⁻¹⁶10⁻¹³10⁻¹⁰10⁻⁷10⁻⁴log₁₀ b, the couplingrelative errorsmall half, directstructure-preservingsmall half, by 1/λone divisionlarge half, direct3.5·10⁻¹⁵small half, direct1.6·10⁻¹¹small half, by 1/λ1.6·10⁻¹⁵structure-preserving3.5·10⁻⁶the structure is not decorationit is where half the accuracy is

A palindromic quadratic of size 4 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 3.46·10⁻¹⁵ at every stop and the small ones to 1.626·10⁻¹¹ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 1.56·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 3.473·10⁻⁶, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.

n: 8

The arguments are the ones A perturbation that keeps the symmetry passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

What a reciprocal pairing is worth: three ways to the small half of a palindromic spectrumA palindromic quadratic of size 8 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 4.94·10⁻¹⁵ at every stop and the small ones to 4.533·10⁻⁴ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 2.82·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 9.185·10⁻⁶, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.1357910⁻¹⁶10⁻¹³10⁻¹⁰10⁻⁷10⁻⁴log₁₀ b, the couplingrelative errorsmall half, directstructure-preservingsmall half, by 1/λone divisionlarge half, direct4.9·10⁻¹⁵small half, direct4.5·10⁻⁴small half, by 1/λ2.8·10⁻¹⁵structure-preserving9.2·10⁻⁶the structure is not decorationit is where half the accuracy is

A palindromic quadratic of size 8 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 4.94·10⁻¹⁵ at every stop and the small ones to 4.533·10⁻⁴ at the far end. Taking the reciprocals of the large ones instead returns the small ones to 2.82·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 9.185·10⁻⁶, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.

n: 10

The arguments are the ones A perturbation that keeps the symmetry passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

What a reciprocal pairing is worth: three ways to the small half of a palindromic spectrumA palindromic quadratic of size 10 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 7.31·10⁻¹⁵ at every stop and the small ones to 7.925 at the far end. Taking the reciprocals of the large ones instead returns the small ones to 4.56·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 2.468·10⁻⁵, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.1357910⁻¹⁶10⁻¹³10⁻¹⁰10⁻⁷10⁻⁴log₁₀ b, the couplingrelative errorsmall half, directstructure-preservingsmall half, by 1/λone divisionlarge half, direct7.3·10⁻¹⁵small half, direct7.9small half, by 1/λ4.6·10⁻¹⁵structure-preserving2.5·10⁻⁵the structure is not decorationit is where half the accuracy is

A palindromic quadratic of size 10 whose spectrum spreads by two decades for every decade of b. The general solver returns the large eigenvalues to 7.31·10⁻¹⁵ at every stop and the small ones to 7.925 at the far end. Taking the reciprocals of the large ones instead returns the small ones to 4.56·10⁻¹⁵ — seven orders, for a division, out of a symmetry the solver discarded. The structure-preserving route, which enforces the pairing exactly, is the worst of the three on the eigenvalues themselves: 2.468·10⁻⁵, because each pair comes from one computed number and both members carry its error. Preserving a symmetry and using one are different acts with different prices.

What it checked while drawing

Every figure above checked its own claims on the way to being drawn, and a claim that failed would have stopped the picture rather than shipped a wrong one. Those checks used to leave no trace at all: a passing one returned true and the only evidence the figure had checked anything was that nothing crashed. The list below is what they actually said, collected by running this generator with an observer installed — not a description of what it is believed to check.

14 distinct claims across 6 sets of arguments, grouped below by shape — because most of them are one sentence with a different number in it, and how many separate times that sentence was put to the test is the informative part.

a Cholesky factor of the second matrix, which requires it to be positive definite

a coupling for which both Cayley blocks are definite

a linearisation has as many eigenvalues as it has rows

a real reciprocal pair

a reduction this file knows

a size the closed form can be read at

a z that the Cayley map does not send to infinity

a z² that a real square root can be taken of

and the small half is behind it by a factor the division recovers

Jacobi needs a symmetric matrix

LU is for square matrices

matmul shapes agree

no eigenvalue at zero, which a palindromic problem cannot have

the large half is exact at every spread

Against the rule

The rule does not apply to it. It factorises nothing, so there is no residual it could be withholding. That is worth stating rather than leaving blank: a site that reported the rule as satisfied by every generator would be counting mostly generators the rule never reached.

Across the library: the rule bites on 217 of 397 generators — 199 print a residual and 18 are exempt with a published reason; 180 factorise nothing. Read from lib/residual-rule.js, which is the same body the gate enforces from, and the gate's last check fails the build if this page and it disagree about any generator.

Where it is called

Changing this generator changes every figure on this list. That is what makes the list worth publishing rather than keeping in a check script.

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