Generator

Contracting by 0.7668 where the folk rate says 0.85

One function in the graphwalk library, called 11 times across 2 essays. Below: what it draws at its defaults, what it draws at every value an essay asks for, the 25 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 contracting by 0.7668 where the folk rate says 0.85. The PageRank power iteration on a connected fifty-vertex graph, at α = 0.85, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 0.90238 here. The measured contraction over the run is 0.76683. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 1.04·10⁻¹⁶.

pagerank-converge is one function in lib/figures/graphwalk.js — the walk and the ranking — a rate that is not the published one, a positivity the arithmetic loses, and places nothing settles. 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.

Contracting by 0.7668 where the folk rate says 0.85The PageRank power iteration on a connected fifty-vertex graph, at α = 0.85, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 0.90238 here. The measured contraction over the run is 0.76683. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 1.04·10⁻¹⁶.01428425670849810⁻¹⁶10⁻¹⁴10⁻¹²10⁻¹⁰10⁻⁸10⁻⁶10⁻⁴10⁻²iterationchange between iteratestwo rates, one curveα0.85λ₂(P)0.9predicted rate0.77measured0.77iterations108against the solve10⁻¹⁶the upper dashed line is αᵏthe curve is on the other one

The PageRank power iteration on a connected fifty-vertex graph, at α = 0.85, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 0.90238 here. The measured contraction over the run is 0.76683. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 1.04·10⁻¹⁶.

kind: "reducible"

The arguments are the ones A chain with no stationary vector passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

The published rate is α, and it is α because the graph is in piecesThe PageRank power iteration on a link graph in two closed pieces, at α = 0.85, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 1 here. The measured contraction over the run is 0.84123. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 1.39·10⁻¹⁶.02244668811013215417610⁻¹⁶10⁻¹⁴10⁻¹²10⁻¹⁰10⁻⁸10⁻⁶10⁻⁴10⁻²iterationchange between iteratestwo rates, one curveα0.85λ₂(P)1predicted rate0.85measured0.84iterations176against the solve1.4·10⁻¹⁶the upper dashed line is αᵏthe curve is on the other one

The PageRank power iteration on a link graph in two closed pieces, at α = 0.85, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 1 here. The measured contraction over the run is 0.84123. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 1.39·10⁻¹⁶.

kind: "reducible", alpha: 0.5

The arguments are the ones A chain with no stationary vector passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

The published rate is α, and it is α because the graph is in piecesThe PageRank power iteration on a link graph in two closed pieces, at α = 0.5, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 1 here. The measured contraction over the run is 0.48946. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 5.2·10⁻¹⁷.051015202530354010⁻¹⁶10⁻¹⁴10⁻¹²10⁻¹⁰10⁻⁸10⁻⁶10⁻⁴10⁻²iterationchange between iteratestwo rates, one curveα0.5λ₂(P)1predicted rate0.5measured0.49iterations43against the solve5.2·10⁻¹⁷the upper dashed line is αᵏthe curve is on the other one

The PageRank power iteration on a link graph in two closed pieces, at α = 0.5, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 1 here. The measured contraction over the run is 0.48946. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 5.2·10⁻¹⁷.

kind: "reducible", alpha: 0.9

The arguments are the ones A chain with no stationary vector passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

The published rate is α, and it is α because the graph is in piecesThe PageRank power iteration on a link graph in two closed pieces, at α = 0.9, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 1 here. The measured contraction over the run is 0.89177. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 1.53·10⁻¹⁶.033669913216519823126410⁻¹⁶10⁻¹⁴10⁻¹²10⁻¹⁰10⁻⁸10⁻⁶10⁻⁴10⁻²iterationchange between iteratestwo rates, one curveα0.9λ₂(P)1predicted rate0.9measured0.89iterations265against the solve1.5·10⁻¹⁶the upper dashed line is αᵏthe curve is on the other one

The PageRank power iteration on a link graph in two closed pieces, at α = 0.9, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 1 here. The measured contraction over the run is 0.89177. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 1.53·10⁻¹⁶.

alpha: 0.85

The arguments are the ones A ranking that is an eigenvector passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

Contracting by 0.7668 where the folk rate says 0.85The PageRank power iteration on a connected fifty-vertex graph, at α = 0.85, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 0.90238 here. The measured contraction over the run is 0.76683. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 1.04·10⁻¹⁶.01428425670849810⁻¹⁶10⁻¹⁴10⁻¹²10⁻¹⁰10⁻⁸10⁻⁶10⁻⁴10⁻²iterationchange between iteratestwo rates, one curveα0.85λ₂(P)0.9predicted rate0.77measured0.77iterations108against the solve10⁻¹⁶the upper dashed line is αᵏthe curve is on the other one

The PageRank power iteration on a connected fifty-vertex graph, at α = 0.85, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 0.90238 here. The measured contraction over the run is 0.76683. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 1.04·10⁻¹⁶.

alpha: 0.99

The arguments are the ones A ranking that is an eigenvector passes. A value nobody placed would be a picture no essay asked for and no claim was ever checked against.

Contracting by 0.8933 where the folk rate says 0.99The PageRank power iteration on a connected fifty-vertex graph, at α = 0.99, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 0.90238 here. The measured contraction over the run is 0.89332. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 2.84·10⁻¹⁶.032649612816019222410⁻¹⁶10⁻¹⁴10⁻¹²10⁻¹⁰10⁻⁸10⁻⁶10⁻⁴10⁻²iterationchange between iteratestwo rates, one curveα0.99λ₂(P)0.9predicted rate0.89measured0.89iterations253against the solve2.8·10⁻¹⁶the upper dashed line is αᵏthe curve is on the other one

The PageRank power iteration on a connected fifty-vertex graph, at α = 0.99, plotted as the change between successive iterates. The upper dashed line is αᵏ, the rate every account of the method quotes. The lower one is (α·λ₂(P))ᵏ, which is what the second eigenvalue of the Google matrix actually is: λ₂(P) = 0.90238 here. The measured contraction over the run is 0.89332. The two agree exactly when λ₂(P) = 1, which happens exactly when the link graph has more than one closed communicating class — which every real one does, and which is why a statement that is false of connected graphs has never been noticed to be. The answer is checked against one elimination of I − αP̃, which agrees to 2.84·10⁻¹⁶.

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.

25 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.

the observed contraction is α·λ₂(P) = 0.767 — checked 9 times

a graph with at least two vertices

a planted partition with no isolated vertex

a positive weight

a teleportation parameter a power iteration can be run at

a teleportation parameter strictly inside (0, 1)

an arc inside the vertex set

every endpoint inside the vertex set

Jacobi needs a symmetric matrix

LU is for square matrices

no arc given twice

no edge given twice

no isolated vertex, which the normalisation divides by

no self-link

no self-loop

one of the two link graphs

the iteration and the elimination agree

Against the rule

It draws a decomposition and prints its residual. It calls walkSpectrum, pagerankSolve, 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.

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