Generator

harmonic

A generator in the analysis library, called 13 times across 2 essays. Below: what it draws at its defaults and at each mode an essay asks for, what it checks while drawing, and everywhere it is used.

harmonic is one function. Everything below came out of it during this build, at parameters taken from the essays rather than invented for this page — so a figure here is the same figure a reader meets in an essay, and if the generator changes, this page changes with it.

At its defaults

Terms that vanish, a total that does notThe first 24 terms of the harmonic series as bars, with the running total above them. The last bar is 0.042 tall and the total has reached 3.776.246810121416182022240123ntotal 3.776term 0.042

show: "blocks"

Oresme's blocksThe harmonic series bracketed into blocks of 1, 1, 2, 4, 8, … terms. Every block after the first sums to at least a half, marked by the upright line, so the total passes any bound.each block after the first clears a half1/11.00001/20.50001/3 … 1/40.58331/5 … 1/80.63451/9 … 1/160.6629

show: "growth"

Divergent, and extremely slowPartial sums of the harmonic series out to n = 10,000, against ln n. The two stay a constant distance apart — γ ≈ 0.5772 — so the total grows like a logarithm.2000400060008000100000246810ntotalH(n) = 9.788ln n

show: "overhang"

Leaning off the table8 identical blocks, each overhanging the one below by 1/(2k) of a block length. The total overhang is half the harmonic number, here 1.359 block lengths.1.359 block lengthsand unboundedtable edge

show: "alternating"

The same terms, with the signs alternatingThe partial sums of 1 - 1/2 + 1/3 - 1/4 + …, out to 24 terms. They close on 0.69315 from both sides at once, and the gap between consecutive sums is the next term, so the answer is trapped.246810121416182022240.60.70.80.91terms usedln 2 = 0.69315odd sums, from aboveeven sums, from below

show: "rearranged"

The same terms, in a different orderThe terms of the alternating harmonic series taken greedily: positives until the total passes 1.6, then one negative, and repeat. Nothing has been added or removed and the total now settles at 1.6 instead of 0.6931.02040608010012000.511.52terms usedaimed at 1.6in order: 0.6931

What it checks while it draws

Collected by running the family and listening to lib/verify.js, not written here. The count is how many separate times this build put that claim to the test.

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 · What the figures prove