Fix davidson-harel layout crash on graphs > 1024 nodes (#362)#373
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AllenLarocque wants to merge 1 commit into
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Fix davidson-harel layout crash on graphs > 1024 nodes (#362)#373AllenLarocque wants to merge 1 commit into
AllenLarocque wants to merge 1 commit into
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heat_tree(layout = "davidson-harel") errored with "The value <x> is not representable as an integer. Invalid value" from igraph whenever a connected component of the graph exceeded 1024 nodes. igraph::layout_with_dh() requires an integer `fineiter`, but layout_functions() computed it as `max(10, log2(vcount(graph))) * effort`. `log2(vcount)` is non-integer once vcount > 1024 (2^10), so igraph rejected it. Round `fineiter` (and `maxiter`, defensively for non-integer `effort`) to integers. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Fixes #362. It turns out AI can figure out stuff that I can't :)
Problem
heat_tree(..., layout = "davidson-harel")errors on larger graphs:Root cause
igraph::layout_with_dh()requires an integerfineiter. Inlayout_functions()(R/heat_tree--layouts.R) it is computed as:log2(vcount)becomes non-integer as soon as a (connected component of the) graph exceeds 1024 nodes (2^10) — e.g.log2(1598) ≈ 10.64, the exact value in the error. igraph then rejects it. This is why the crash is size-dependent: small graphs (and forests of small components, which metacoder lays out per-component) stay under the threshold, while a single large connected tree trips it.Fix
Round
fineiterto an integer (andmaxiter, defensively, in caseeffortis non-integer). Behaviour is unchanged below 1024 nodes; above it, the layout now runs instead of erroring.Verification
igraph::layout_with_dh(g, fineiter = log2(vcount(g)))reproduces the error on a >1024-node graph;fineiter = round(...)succeeds.heat_tree(layout = "davidson-harel")renders a real ~1,500-node taxonomic tree that previously crashed.Reported by several users over the last few years in #362 — hopefully this unblocks them.
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