qtl2fst
The out-of-memory backend for R/qtl2, feature-complete since 2020 and now purely on upkeep
Comparison · Analytics
lstar vs PurpleAir
A side-by-side editorial comparison of lstar and PurpleAir — release velocity, themes, recent moves, and the top alternatives to consider.
lstar vs PurpleAir: at a glance
What is lstar?
A single-cell data store commits to Zarr v3 and range-readable hosting across four language surfaces
lstar stores single-cell data behind one C++ core with Python, R and JS/WASM bindings, and ships a browser viewer that reads the store directly. Zarr v3 is now the default on-disk format across all four surfaces, with zstd compression and sharding that packs many chunks into fewer objects. Viewer stores are compressed per field and resolved at chunk granularity, so a hosted viewer fetches only what it displays. The tag stream carries both lstar and lstar-sc releases.
What is PurpleAir?
The R client for PurpleAir sensors keeps finding its time-averaging was wrong.
PurpleAir is a small R client for the PurpleAir air quality sensor API, covering sensor queries, historical readings, and — more recently — finding a sensor on the local network by IP address and id. Authentication has been simplified to an environment variable only, with the redundant key argument removed. The package is maintained reactively, and most of what ships is correctness work on the queries it already makes.
lstar vs PurpleAir: editorial side-by-side
lstar
5.0ANALYTICS
A single-cell data store commits to Zarr v3 and range-readable hosting across four language surfaces
◆ Current state
lstar stores single-cell data behind one C++ core with Python, R and JS/WASM bindings, and ships a browser viewer that reads the store directly. Zarr v3 is now the default on-disk format across all four surfaces, with zstd compression and sharding that packs many chunks into fewer objects. Viewer stores are compressed per field and resolved at chunk granularity, so a hosted viewer fetches only what it displays. The tag stream carries both lstar and lstar-sc releases.
◆ Where it's heading
The through-line is making a hosted store cheap to read. Sharding addresses the file-per-chunk explosion that makes many-chunk arrays awkward to host; per-field compression with chunk-granular resolution means colouring an embedding by one gene fetches one column rather than an array. The 0.2.x patches are the cost of maintaining four surfaces at once — a WASM heap crash that only browsers exercise, and a count-basis orientation defect where all three surfaces normalized in memory and none owned the on-disk layout.
◆ Prediction
The orientation bug's root cause — no surface owning the on-disk representation while all three normalized in memory — is the kind of gap that usually produces a validation or ownership change rather than another point fix.
PurpleAir
0.0ANALYTICS
The R client for PurpleAir sensors keeps finding its time-averaging was wrong.
◆ Current state
PurpleAir is a small R client for the PurpleAir air quality sensor API, covering sensor queries, historical readings, and — more recently — finding a sensor on the local network by IP address and id. Authentication has been simplified to an environment variable only, with the redundant key argument removed. The package is maintained reactively, and most of what ships is correctness work on the queries it already makes.
◆ Where it's heading
The recurring theme is time aggregation. Weekly, monthly and yearly average intervals were wrong and fixed in one release; the weekly average was wrong again and fixed in the next. For an air quality package that is not incidental — averaging window is what turns a stream of sensor readings into an exposure estimate, and downstream analyses inherit the error silently. The other thread is failing earlier and more clearly: explicit errors for spatial inputs the sensor query does not accept, better index parsing so malformed requests never reach the API, and handling for history calls that return nothing. Local sensor discovery is the one genuine capability addition, opening a path that does not depend on the cloud API at all.
◆ Prediction
On this record, further aggregation and input-validation fixes are the likeliest next releases; whether local network access grows past discovery into full local data retrieval is not something the entries indicate.
Alternatives to lstar and PurpleAir
Other Analytics products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either lstar or PurpleAir.
mmconvert
A single-purpose mouse map interpolator that solved its problem in 2023 and has coasted since
qtl2convert
A conversion utility in pure maintenance mode, tracking R-devel breakage release by release
piecepackr
A board game graphics package runs one of the most disciplined deprecation cycles in R.
e2tree
The explainable-ensemble-tree package now measures whether its own explanations are faithful.
discretefdr
The discrete-data FDR package is being pared into one piece of a larger multiple-testing suite.
See all lstar alternatives → · See all PurpleAir alternatives →
Recent activity from lstar and PurpleAir
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 21d agolstarViewer count-basis orientation fixed; existing stores need re-prep
- 26d agolstarWASM viewer crash on resizable heaps fixed
- 1mo agolstarlstar 0.2.0 ⚡
- 1mo agolstarMeasure state inferred from content, not slot name
- 3mo agoPurpleAirWeekly averages fixed again; API key argument dropped
- 10mo agoPurpleAirLocal sensor discovery, and averaging intervals corrected
- 1y agoPurpleAirBounding box sensor queries fixed
Frequently asked questions
What is the difference between lstar and PurpleAir?
They serve adjacent needs but don't currently overlap on shipped themes. lstar is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is lstar better than PurpleAir?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. lstar is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.
What are the best alternatives to lstar?
Top lstar alternatives in Analytics are ranked by recent ship velocity. Browse the "lstar alternatives" section above for the current picks, or visit /alternatives/lstar for the full list with editorial commentary on each.
What are the best alternatives to PurpleAir?
Top PurpleAir alternatives in Analytics are ranked by recent ship velocity. Browse the "PurpleAir alternatives" section above for the current picks, or visit /alternatives/purpleair for the full list with editorial commentary on each.