moment-conditioning
At its defaults it draws what the higher moments cost, and the one division that removes it. The condition number of the block Hankel against K, on a contour of radius 6, integrating in z and in the scaled variable (z − c)/ρ. Unscaled, ‖Aₚ‖ grows like ρᵖ, so the block Hankel of K moments is graded over ρ²ᴷ and its condition number rises at exactly the rate the ceiling does — from 1.28 to 2.26·10⁶ across six moments. Scaled, it runs 1.28 to 1750, a factor of 1290 better at the far end. The scaled variable is on the unit circle, so every moment is the same size; the cost is one division per quadrature point and the eigenvalues come back with c + ρ× applied.
moment-conditioning is one function in lib/figures/beyn.js —
a ceiling with a knob on it — higher contour moments, and the conditioning that rises with them. 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.
The condition number of the block Hankel against K, on a contour of radius 6, integrating in z and in the scaled variable (z − c)/ρ. Unscaled, ‖Aₚ‖ grows like ρᵖ, so the block Hankel of K moments is graded over ρ²ᴷ and its condition number rises at exactly the rate the ceiling does — from 1.28 to 2.26·10⁶ across six moments. Scaled, it runs 1.28 to 1750, a factor of 1290 better at the far end. The scaled variable is on the unit circle, so every moment is the same size; the cost is one division per quadrature point and the eigenvalues come back with c + ρ× applied.
radius: 6
The arguments are the ones A ceiling with a knob on it passes. A value drawn at the generator's defaults instead would be a picture no essay asked for and no assertion has been run against.
The condition number of the block Hankel against K, on a contour of radius 6, integrating in z and in the scaled variable (z − c)/ρ. Unscaled, ‖Aₚ‖ grows like ρᵖ, so the block Hankel of K moments is graded over ρ²ᴷ and its condition number rises at exactly the rate the ceiling does — from 1.28 to 2.26·10⁶ across six moments. Scaled, it runs 1.28 to 1750, a factor of 1290 better at the far end. The scaled variable is on the unit circle, so every moment is the same size; the cost is one division per quadrature point and the eigenvalues come back with c + ρ× applied.
radius: 3
The arguments are the ones The conditioning that rises with the ceiling passes. A value drawn at the generator's defaults instead would be a picture no essay asked for and no assertion has been run against.
The condition number of the block Hankel against K, on a contour of radius 3, integrating in z and in the scaled variable (z − c)/ρ. Unscaled, ‖Aₚ‖ grows like ρᵖ, so the block Hankel of K moments is graded over ρ²ᴷ and its condition number rises at exactly the rate the ceiling does — from 5.67 to 3071 across six moments. Scaled, it runs 5.67 to 12.2, a factor of 251 better at the far end. The scaled variable is on the unit circle, so every moment is the same size; the cost is one division per quadrature point and the eigenvalues come back with c + ρ× applied.
radius: 5
The arguments are the ones The conditioning that rises with the ceiling passes. A value drawn at the generator's defaults instead would be a picture no essay asked for and no assertion has been run against.
The condition number of the block Hankel against K, on a contour of radius 5, integrating in z and in the scaled variable (z − c)/ρ. Unscaled, ‖Aₚ‖ grows like ρᵖ, so the block Hankel of K moments is graded over ρ²ᴷ and its condition number rises at exactly the rate the ceiling does — from 1.28 to 2.26·10⁶ across six moments. Scaled, it runs 1.28 to 695, a factor of 3250 better at the far end. The scaled variable is on the unit circle, so every moment is the same size; the cost is one division per quadrature point and the eigenvalues come back with c + ρ× applied.
radius: 10
The arguments are the ones The conditioning that rises with the ceiling passes. A value drawn at the generator's defaults instead would be a picture no essay asked for and no assertion has been run against.
The condition number of the block Hankel against K, on a contour of radius 10, integrating in z and in the scaled variable (z − c)/ρ. Unscaled, ‖Aₚ‖ grows like ρᵖ, so the block Hankel of K moments is graded over ρ²ᴷ and its condition number rises at exactly the rate the ceiling does — from 1.28 to 2.26·10⁶ across six moments. Scaled, it runs 1.28 to 3.37·10⁴, a factor of 67.1 better at the far end. The scaled variable is on the unit circle, so every moment is the same size; the cost is one division per quadrature point and the eigenvalues come back with c + ρ× applied.
radius: 15
The arguments are the ones The conditioning that rises with the ceiling passes. A value drawn at the generator's defaults instead would be a picture no essay asked for and no assertion has been run against.
The condition number of the block Hankel against K, on a contour of radius 15, integrating in z and in the scaled variable (z − c)/ρ. Unscaled, ‖Aₚ‖ grows like ρᵖ, so the block Hankel of K moments is graded over ρ²ᴷ and its condition number rises at exactly the rate the ceiling does — from 1.22 to 7.37·10⁸ across six moments. Scaled, it runs 1.22 to 3952, a factor of 1.9·10⁵ better at the far end. The scaled variable is on the unit circle, so every moment is the same size; the cost is one division per quadrature point and the eigenvalues come back with c + ρ× applied.
What it checked while drawing
Every figure above asserted its own claims on the way to being drawn, and a claim that failed
would have failed the build rather than drawn a wrong picture. Those assertions 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.
8 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 contour the closed form covers
a division by a complex number that is not zero
a Lambert argument that is not zero
a size the contour integrals can afford
and the gap grows with the number of moments
enough moments for the block asked for
LU is for square matrices
the unscaled block Hankel is worse conditioned
Against the rule
It draws a decomposition and prints its residual. It calls
contourMoments, momentRank,
and every figure above carries the badge — which residualcheck verifies by looking
for it in the emitted SVG rather than by finding the call that builds one. A badge that is
constructed and then left out of the body is the failure that check exists for.
Across the library: the rule bites on 192
of 346 generators —
174 print a residual and
18 are exempt with a published reason;
154 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.
A ceiling with a knob on it
A contour method returns at most as many eigenvalues as its probe block has columns, and the object that comes back does not distinguish that from having found everything. One line of the derivation multiplies the ceiling by a number the caller chooses, and it costs no extra solves at all.
The eigenvalue problem that is not linearThe conditioning that rises with the ceiling
Higher moments multiply a contour method's ceiling by K and grade its block Hankel over ρ to the 2K, so the two knobs are the same knob. One division per quadrature point separates them, and the measurement of what it is worth grows from twenty to twenty thousand.