train-accuracy
At its defaults it draws the largest train rank of a 5-index reciprocal tensor against the accuracy asked for. Every point is a decomposition that met its tolerance: the measured errors are 0.0041, 4.2·10⁻⁴, 3.4·10⁻⁵, 3.3·10⁻⁷, 5.7·10⁻⁹, 6.6·10⁻¹², 1.6·10⁻¹³ against tolerances of 10⁻², 10⁻³, 10⁻⁴, 10⁻⁶, 10⁻⁸, 10⁻¹⁰ and 10⁻¹². The rank runs 3, 4, 5, 7, 8, 10, 11 and the storage 264, 448, 680, 1,160, 1,664, 2,208, 2,504, against 32,768 entries. That is 0.80 of rank per decade of accuracy over the whole range — a constant, with no cliff and no regime where a digit costs more than the last one, which is the same shape the hierarchy field measured for a kernel matrix and is not something either field's geometry promises.
train-accuracy is one function in lib/figures/ttrain.js —
the train — one rank per cut of the index list, and the iterate that must be cut back. 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.
Every point is a decomposition that met its tolerance: the measured errors are 0.0041, 4.2·10⁻⁴, 3.4·10⁻⁵, 3.3·10⁻⁷, 5.7·10⁻⁹, 6.6·10⁻¹², 1.6·10⁻¹³ against tolerances of 10⁻², 10⁻³, 10⁻⁴, 10⁻⁶, 10⁻⁸, 10⁻¹⁰ and 10⁻¹². The rank runs 3, 4, 5, 7, 8, 10, 11 and the storage 264, 448, 680, 1,160, 1,664, 2,208, 2,504, against 32,768 entries. That is 0.80 of rank per decade of accuracy over the whole range — a constant, with no cliff and no regime where a digit costs more than the last one, which is the same shape the hierarchy field measured for a kernel matrix and is not something either field's geometry promises.
d: 5
The arguments are the ones An iterate that must be made smaller 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.
Every point is a decomposition that met its tolerance: the measured errors are 0.0041, 4.2·10⁻⁴, 3.4·10⁻⁵, 3.3·10⁻⁷, 5.7·10⁻⁹, 6.6·10⁻¹², 1.6·10⁻¹³ against tolerances of 10⁻², 10⁻³, 10⁻⁴, 10⁻⁶, 10⁻⁸, 10⁻¹⁰ and 10⁻¹². The rank runs 3, 4, 5, 7, 8, 10, 11 and the storage 264, 448, 680, 1,160, 1,664, 2,208, 2,504, against 32,768 entries. That is 0.80 of rank per decade of accuracy over the whole range — a constant, with no cliff and no regime where a digit costs more than the last one, which is the same shape the hierarchy field measured for a kernel matrix and is not something either field's geometry promises.
d: 3
The arguments are the ones The format that does not notice the dimension 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.
Every point is a decomposition that met its tolerance: the measured errors are 0.0023, 1.3·10⁻⁴, 5.1·10⁻⁶, 1.4·10⁻⁷, 2.2·10⁻⁹, 8.6·10⁻¹⁶, 8.6·10⁻¹⁶ against tolerances of 10⁻², 10⁻³, 10⁻⁴, 10⁻⁶, 10⁻⁸, 10⁻¹⁰ and 10⁻¹². The rank runs 3, 4, 5, 6, 7, 8, 8 and the storage 120, 192, 280, 384, 504, 640, 640, against 512 entries. That is 0.50 of rank per decade of accuracy over the whole range — a constant, with no cliff and no regime where a digit costs more than the last one, which is the same shape the hierarchy field measured for a kernel matrix and is not something either field's geometry promises.
d: 4
The arguments are the ones The format that does not notice the dimension 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.
Every point is a decomposition that met its tolerance: the measured errors are 0.0036, 2.9·10⁻⁴, 1.8·10⁻⁵, 2.6·10⁻⁷, 5.4·10⁻⁹, 3.6·10⁻¹¹, 1.4·10⁻¹⁴ against tolerances of 10⁻², 10⁻³, 10⁻⁴, 10⁻⁶, 10⁻⁸, 10⁻¹⁰ and 10⁻¹². The rank runs 3, 4, 5, 7, 8, 9, 11 and the storage 192, 320, 480, 768, 1,008, 1,280, 1,536, against 4,096 entries. That is 0.80 of rank per decade of accuracy over the whole range — a constant, with no cliff and no regime where a digit costs more than the last one, which is the same shape the hierarchy field measured for a kernel matrix and is not something either field's geometry promises.
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.
9 distinct claims across 4 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 train meets 10^-2 — asserted 7 times
a number of indices the sweep can afford
and a tighter tolerance costs rank
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 146
of 287 generators —
131 print a residual and
15 are exempt with a published reason;
141 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.
An iterate that must be made smaller
Applying a Kronecker-sum operator to a low-rank iterate multiplies its ranks by d and adding two of them adds their ranks, so a solver in a compressed format cannot keep what it produces. Every step is followed by a truncation — and whether that truncation is a floor on the residual depends on the right-hand side rather than on the truncation.
Randomised, and the guarantee that changes kindSketching what is never unfolded
A range finder multiplies its matrix by a few random vectors. For a mode-k unfolding those vectors have n^{d−1} entries, so the random object is the size of the tensor divided by n — and by six indices it is larger than the tensor it is sketching.
When the index is a tupleThe format that does not notice the dimension
A Tucker core is r^d numbers, so the format that repaired the definition still cannot go past five indices. Cutting between the indices rather than across them gives d − 1 ranks instead of d, storage linear in the number of indices, and a family whose ranks are two everywhere by an addition formula.
Where the flop count stopped predicting the timeThe order the products are taken in
The sparsity field's first essay says the elimination order decides the memory. This is the same sentence about arithmetic: a contraction of several tensors over shared indices has one value and many evaluation orders, and on the inner product of two trains they differ by a factor of two million.
Neither sparse nor denseThe size the rank does not notice
Sample a kernel block at 32, 64, 128 and 256 points a side and it needs five columns, five, five and five. Sample the touching block next to it at the same four sizes and it needs nine, eleven, twelve and thirteen. Same kernel, same accuracy, one number and a logarithm.