Generator

A randomised rank-k solve, 4 seeds a rank

One function in the compose library, called 9 times across 3 essays. Below: what it draws at its defaults, what it draws at every value an essay asks for, the 6 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 a randomised rank-k solve, 4 seeds a rank. Relative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.84 wide at rank 8, where the method is at its worst, and 1.022 wide at rank 24, where it is at its best. The same computation on the same data returns a different answer each time.

rank-band is one function in lib/figures/compose.js — four knobs — one floor under them, and a fifth that is not a knob at all. 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.

A randomised rank-k solve, 4 seeds a rankRelative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.84 wide at rank 8, where the method is at its worst, and 1.022 wide at rank 24, where it is at its best. The same computation on the same data returns a different answer each time.0481216202428321rank keptrelative errormedianthe answer movesspread at rank 81.8spread at rank 241best median error0.14widest where the method is worstand the bound does not say so

Relative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.84 wide at rank 8, where the method is at its worst, and 1.022 wide at rank 24, where it is at its best. The same computation on the same data returns a different answer each time.

seeds: 4

The arguments are the ones An answer that changes with the seed passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

A randomised rank-k solve, 4 seeds a rankRelative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.84 wide at rank 8, where the method is at its worst, and 1.022 wide at rank 24, where it is at its best. The same computation on the same data returns a different answer each time.0481216202428321rank keptrelative errormedianthe answer movesspread at rank 81.8spread at rank 241best median error0.14widest where the method is worstand the bound does not say so

Relative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.84 wide at rank 8, where the method is at its worst, and 1.022 wide at rank 24, where it is at its best. The same computation on the same data returns a different answer each time.

noise: 0.1

The arguments are the ones An answer that changes with the seed passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

A randomised rank-k solve, 4 seeds a rankRelative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.81 wide at rank 8, where the method is at its worst, and 1.095 wide at rank 12, where it is at its best. The same computation on the same data returns a different answer each time.048121620242832110¹rank keptrelative errormedianthe answer movesspread at rank 81.8spread at rank 121.1best median error0.17widest where the method is worstand the bound does not say so

Relative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.81 wide at rank 8, where the method is at its worst, and 1.095 wide at rank 12, where it is at its best. The same computation on the same data returns a different answer each time.

noise: 0.001

The arguments are the ones An answer that changes with the seed passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

A randomised rank-k solve, 4 seeds a rankRelative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.84 wide at rank 8, where the method is at its worst, and 1.004 wide at rank 28, where it is at its best. The same computation on the same data returns a different answer each time.04812162024283210⁻¹1rank keptrelative errormedianthe answer movesspread at rank 81.8spread at rank 281best median error0.11widest where the method is worstand the bound does not say so

Relative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.84 wide at rank 8, where the method is at its worst, and 1.004 wide at rank 28, where it is at its best. The same computation on the same data returns a different answer each time.

n: 96

The arguments are the ones An answer that changes with the seed passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

A randomised rank-k solve, 4 seeds a rankRelative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 2.02 wide at rank 4, where the method is at its worst, and 1.010 wide at rank 28, where it is at its best. The same computation on the same data returns a different answer each time.04812162024283210⁻¹1rank keptrelative errormedianthe answer movesspread at rank 42spread at rank 281best median error0.11widest where the method is worstand the bound does not say so

Relative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 2.02 wide at rank 4, where the method is at its worst, and 1.010 wide at rank 28, where it is at its best. The same computation on the same data returns a different answer each time.

seeds: 3

The arguments are the ones An answer that changes with the seed passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

A randomised rank-k solve, 3 seeds a rankRelative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.71 wide at rank 8, where the method is at its worst, and 1.007 wide at rank 24, where it is at its best. The same computation on the same data returns a different answer each time.0481216202428321rank keptrelative errormedianthe answer movesspread at rank 81.7spread at rank 241best median error0.15widest where the method is worstand the bound does not say so

Relative error against the rank kept, on a logarithmic vertical axis, with a vertical bar at each rank spanning the seeds. The band is 1.71 wide at rank 8, where the method is at its worst, and 1.007 wide at rank 24, where it is at its best. The same computation on the same data returns a different answer each time.

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.

6 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 size the randomised solve is affordable at

and barely at all at the optimum

enough seeds for a band and few enough to draw

matmul shapes agree

the seed changes the answer somewhere in the range

with the spread worst where the method is worst

Against the rule

It draws a decomposition and prints its residual. It calls rankSweep, 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 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.

The whole library · All essays · What must fail