Generator

gram-schmidt-order

One function in the ortho library, called 4 times across 3 essays. Below: what it draws at its defaults, what it draws at every value an essay asks for, the 13 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 classical and modified gram–schmidt: the same subtraction, in a different order. Two panels of pseudocode differing in one argument, with the resulting pairwise dot products of the computed columns listed beneath each.

gram-schmidt-order is one function in lib/figures/ortho.js — orthogonality — ‖qᵀq − i‖ as a measurement rather than an adjective. 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.

Classical and modified Gram–Schmidt: the same subtraction, in a different orderTwo panels of pseudocode differing in one argument, with the resulting pairwise dot products of the computed columns listed beneath each.for each previous column i, subtract the projection of column j onto qᵢclassicalr[i][j] = qᵢ · a[j] ↑ the ORIGINAL columnv = v − r[i][j] · qᵢthe three worst |qᵢ · qⱼ|:columns 7 and 8: 1columns 6 and 8: 0.13columns 6 and 7: 0.13modifiedr[i][j] = qᵢ · v ↑ what is LEFT of itv = v − r[i][j] · qᵢthe three worst |qᵢ · qⱼ|:columns 1 and 8: 4.4·10⁻⁷columns 2 and 8: 2.7·10⁻⁷columns 3 and 8: 2.4·10⁻⁸The two R factors agree to 1.2·10⁻⁶ relative. The two Q factors do not.the 8×8 Hilbert matrixone word, eight orders

Two panels of pseudocode differing in one argument, with the resulting pairwise dot products of the computed columns listed beneath each.

n: 10

The arguments are the ones A reduction that changes the order 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.

Classical and modified Gram–Schmidt: the same subtraction, in a different orderTwo panels of pseudocode differing in one argument, with the resulting pairwise dot products of the computed columns listed beneath each.for each previous column i, subtract the projection of column j onto qᵢclassicalr[i][j] = qᵢ · a[j] ↑ the ORIGINAL columnv = v − r[i][j] · qᵢthe three worst |qᵢ · qⱼ|:columns 8 and 9: 1columns 9 and 10: 1columns 7 and 8: 1modifiedr[i][j] = qᵢ · v ↑ what is LEFT of itv = v − r[i][j] · qᵢthe three worst |qᵢ · qⱼ|:columns 2 and 10: 1.8·10⁻⁴columns 1 and 10: 3.2·10⁻⁵columns 4 and 10: 7.9·10⁻⁶The two R factors agree to 2.9·10⁻⁶ relative. The two Q factors do not.the 10×10 Hilbert matrixone word, eight orders

Two panels of pseudocode differing in one argument, with the resulting pairwise dot products of the computed columns listed beneath each.

n: 8

The arguments are the ones An orthogonalisation nobody calls one 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.

Classical and modified Gram–Schmidt: the same subtraction, in a different orderTwo panels of pseudocode differing in one argument, with the resulting pairwise dot products of the computed columns listed beneath each.for each previous column i, subtract the projection of column j onto qᵢclassicalr[i][j] = qᵢ · a[j] ↑ the ORIGINAL columnv = v − r[i][j] · qᵢthe three worst |qᵢ · qⱼ|:columns 7 and 8: 1columns 6 and 8: 0.13columns 6 and 7: 0.13modifiedr[i][j] = qᵢ · v ↑ what is LEFT of itv = v − r[i][j] · qᵢthe three worst |qᵢ · qⱼ|:columns 1 and 8: 4.4·10⁻⁷columns 2 and 8: 2.7·10⁻⁷columns 3 and 8: 2.4·10⁻⁸The two R factors agree to 1.2·10⁻⁶ relative. The two Q factors do not.the 8×8 Hilbert matrixone word, eight orders

Two panels of pseudocode differing in one argument, with the resulting pairwise dot products of the computed columns listed beneath each.

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.

13 distinct claims across 3 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.

classical column 0 is still a unit vector agree — asserted 10 times

and both produce the same R to within κu

classical leaves the columns measurably non-perpendicular

while Q differs by far more than R does

Against the rule

It calls a factoriser without drawing a factorisation (gramSchmidt), so the rule is written down as not applying, with the reason: prints the pairwise dot products, which is ‖QᵀQ − I‖ entry by entry

The exemption list is the interesting half of the rule rather than an escape hatch — it is where a decision about a figure had to be argued in one line. residualcheck refuses an exemption that is not doing work, and rejected ten of the fifteen written for the expansion's figures on exactly that ground: a figure whose vertical axis is a residual satisfies the rule by construction, and touching a factoriser does not by itself require an entry.

Across the library: the rule bites on 52 of 99 generators — 37 print a residual and 15 are exempt with a published reason; 47 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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