← Back to home
Comparison · Analytics

ggtrace vs skylight

A side-by-side editorial comparison of ggtrace and skylight — release velocity, themes, recent moves, and the top alternatives to consider.

Shared themes:r-package

ggtrace vs skylight: at a glance

Featureggtraceskylight
SectorAnalyticsAnalytics
Velocity score0.00.0
Sparks · 30d00
Top themesggplot2, debugging, ggproto, developer-toolingastronomy, illuminance, cpp-port, scientific-computing
Last editorial update1h ago2h ago
WebsiteVisit →Visit →

What is ggtrace?

A debugger for ggplot2's internals, hardening its grip as the internals it traces keep moving.

ggtrace lets users step inside ggplot2's rendering pipeline — tracing ggproto methods, dumping intermediate state, and snapshotting layer data at each stage via layer_before_stat(), layer_after_stat(), layer_before_geom() and layer_after_scale(). The workflow functions gained short aliases at 0.7.1, and recent releases have gone into making method resolution work on ggproto definitions written in forms the tracer did not originally expect.

Read the full ggtrace trajectory →

What is skylight?

A frozen astronomical model quietly became the inner loop of its sibling's optimizer.

skylight returns sun and moon illuminance, azimuth and altitude for a given date, time and location, implemented as a near-verbatim transcription of a 1987 US Naval Observatory circular. The model formulation has not changed since the initial 2022 release and the author states so explicitly. Everything shipped since has been packaging, citation and speed: v1.3 moved the main routine from R to C++, and v1.4 removed a parameter check that was flooding the console with messages.

Read the full skylight trajectory →

ggtrace vs skylight: editorial side-by-side

G
ggtrace
ANALYTICS
0.0

A debugger for ggplot2's internals, hardening its grip as the internals it traces keep moving.

◆ Current state

ggtrace lets users step inside ggplot2's rendering pipeline — tracing ggproto methods, dumping intermediate state, and snapshotting layer data at each stage via layer_before_stat(), layer_after_stat(), layer_before_geom() and layer_after_scale(). The workflow functions gained short aliases at 0.7.1, and recent releases have gone into making method resolution work on ggproto definitions written in forms the tracer did not originally expect.

◆ Where it's heading

The package matured from raw tracing primitives into named workflows: 0.6.0 added the sublayer snapshot functions and error-context helpers, 0.7.x has been sanding down how reliably those workflows find and evaluate a method. Three consecutive releases in May 2025, two of them minutes apart, all address the same class of failure — one-liner ggproto methods without braces, and inheritance resolution on instances rather than subclasses. That pattern says the remaining bugs are in method introspection, not in the tracing machinery itself.

◆ Prediction

Expect continued fixes to method resolution as ggplot2's ggproto definitions vary, and realignment work when ggplot2 4.x changes internals this package deliberately reaches into. The entries do not signal new workflow functions.

S
skylight
ANALYTICS
0.0

A frozen astronomical model quietly became the inner loop of its sibling's optimizer.

◆ Current state

skylight returns sun and moon illuminance, azimuth and altitude for a given date, time and location, implemented as a near-verbatim transcription of a 1987 US Naval Observatory circular. The model formulation has not changed since the initial 2022 release and the author states so explicitly. Everything shipped since has been packaging, citation and speed: v1.3 moved the main routine from R to C++, and v1.4 removed a parameter check that was flooding the console with messages.

◆ Where it's heading

This is a reference implementation of a published algorithm rather than a product accumulating features, and it is being maintained that way. The movement that does occur is driven from downstream: the C++ port was written for the inverse-modelling loop in the sibling skytrackr package, which calls skylight repeatedly during optimization. That reframes skylight from a standalone calculator into the compute kernel another package's fitting routine depends on.

◆ Prediction

With the model formulation deliberately fixed and the C++ path already in place, the next release is most likely another small maintenance fix. The entries give no indication of planned new capability.

Alternatives to ggtrace and skylight

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 ggtrace or skylight.

See all ggtrace alternatives → · See all skylight alternatives →

Recent activity from ggtrace and skylight

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 9mo agoskylightNoisy parameter check removed from console output
  2. 10mo agoskylightCore routine moves from R to C++ for repeated-call speed
  3. 1y agoggtraceBrace-less one-liner methods traced gracefully
  4. 1y agoggtraceget_method_inheritance() fixed for class instances
  5. 1y agoggtraceWorkflow functions recognise one-liner ggproto methods
  6. 1y agoggtraceEager layer_is(), clearer method-mismatch errors, consistent tracedump names
  7. 1y agoggtracetrace_steps = "all" added; double-evaluation side effects fixed
  8. 1y agoggtracelayer_is() targets by_layer() downstream directly
  9. 2y agoskylightCitation updated after the companion paper published
  10. 3y agoskylightSkylight v1.1
  11. 3y agoskylightFirst release: sun and moon illuminance from the 1987 USNO circular

Frequently asked questions

What is the difference between ggtrace and skylight?

Both compete on the same themes — r-package — within Analytics. ggtrace and skylight are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is ggtrace better than skylight?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. ggtrace and skylight are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.

What are the best alternatives to ggtrace?

Top ggtrace alternatives in Analytics are ranked by recent ship velocity. Browse the "ggtrace alternatives" section above for the current picks, or visit /alternatives/ggtrace for the full list with editorial commentary on each.

What are the best alternatives to skylight?

Top skylight alternatives in Analytics are ranked by recent ship velocity. Browse the "skylight alternatives" section above for the current picks, or visit /alternatives/skylight for the full list with editorial commentary on each.