--- name: comrade-vlbi-e98cbb2f66b8 description: Event Horizon Telescope black hole imaging with deterministic coloring via Gay.jl integration. metadata: interface_ports: - Commands - Integration with - Related Skills --- # Comrade.jl VLBI Skill Event Horizon Telescope black hole imaging with deterministic coloring via Gay.jl integration. ## Metadata ```yaml name: comrade-vlbi description: Comrade.jl VLBI black hole imaging with VLBISkyModels, Pigeons.jl parallel tempering, and Gay.jl deterministic coloring version: 1.0.0 trit: 0 # ERGODIC - bridges sky models to interferometric observations ``` ## Core Abstractions ### AbstractSkyModel The base type for all sky brightness distributions. Implementations must provide: - `intensity_point(model, p)` - intensity at sky position - `visibility(model, u, v)` - complex visibility at (u,v) ### AbstractInstrumentModel Encodes station-based corruptions: - `gain_terms(instrument, times, stations)` - `phase_calibration(instrument, baseline)` ### VLBIPosterior Combines sky model, instrument model, and data likelihood: ```julia post = VLBIPosterior(skymodel, instrumentmodel, dataproducts) logdensityof(post, θ) # Evaluate posterior at parameters θ ``` ## VLBISkyModels Primitives | Primitive | Description | S-expression | |-----------|-------------|--------------| | `Ring(r, w)` | Circular ring | `(ring radius width)` | | `MRing(r, α, β)` | Azimuthal Fourier ring | `(mring radius [α...] [β...])` | | `Gaussian(σx, σy)` | Elliptical Gaussian | `(gaussian σx σy)` | | `Disk(r)` | Uniform disk | `(disk radius)` | | `Crescent(r_out, r_in, s)` | Asymmetric ring | `(crescent r_out r_in shift)` | ## Model Composition ```julia # Addition model = ring + gaussian # Stretching (ellipticity) stretched(model, sx, sy) # Rotation rotated(model, θ) # Translation shifted(model, Δx, Δy) # Convolution smoothed(ring, gaussian) ``` ## Lisp S-Expression Syntax Gay.jl provides colored S-expression display matching Comrade model structure: ```lisp ;; M87* model as S-expression (parentheses colored by Gay.jl) (sky-add (ring 1.0 0.3) (gaussian 0.5 0.3)) ;; Transformed model (sky-rotate (sky-stretch (mring 0.8 [0.3 0.1] [0.2 -0.1]) 0.67 0.67) 0.785) ;; Sgr A* style (sky-add (crescent 1.2 0.6 0.3) (disk 0.4)) ``` ## GF(3) Conservation The ERGODIC trit (0) reflects Comrade's role as a bridge: ``` Sky Model (PLUS +1) ──╮ ├──▶ Comrade (ERGODIC 0) ──▶ Posterior Samples Observations (MINUS -1)──╯ Σ trits = +1 + (-1) + 0 = 0 ✓ CONSERVED ``` ## Pigeons.jl SplitMix Pattern Both Comrade and Gay.jl leverage the same splittable RNG pattern: ```julia # Pigeons parallel tempering uses splittable RNG # Gay.jl colors use SplitMix64 for determinism # They compose naturally: function colored_posterior_sample(post, seed) gay_seed!(seed) pt = pigeons(target=ascube(post), explorer=SliceSampler()) # Each sample gets deterministic color for θ in sample_array(pt) color = next_color() visualize_sample(θ, color) end end ``` ## Example: Full Pipeline ```julia using Comrade, Pigeons, Gay # 1. Load EHT data obs = load_ehtim_uvfits("M87_2017_101.uvfits") dlcamp = extract_lcamp(obs) dcphase = extract_cphase(obs) # 2. Define sky model with Gay.jl colors gay_seed!(2017_04_11) # Observation date as seed function skymodel(θ) (; r, w, α, β, f, σ) = θ ring = smoothed(MRing((α,), (β,)), Gaussian(w)) gauss = Gaussian(σ) return stretched(ring, r, r) + f * gauss end # 3. Build posterior prior = NamedTuple{(:r,:w,:α,:β,:f,:σ)}( Uniform(μas2rad(10), μas2rad(30)), Uniform(μas2rad(1), μas2rad(10)), Uniform(-0.5, 0.5), Uniform(-0.5, 0.5), Uniform(0.0, 0.3), Uniform(μas2rad(5), μas2rad(50)) ) post = VLBIPosterior(skymodel, prior, dlcamp, dcphase) # 4. Sample with Pigeons.jl (uses SplitMix internally!) pt = pigeons( target = ascube(post), n_rounds = 12, checkpoint = true ) # 5. Visualize with colored sexps for θ in sample_array(pt)[1:5] m = skymodel(θ) println(sky_show(m)) end ``` --- ## End-of-Skill Interface ## Commands ### Create M87* Style Model ```julia using Comrade, Gay gay_seed!(1069) # M87* ring + Gaussian ring = smoothed(stretched(MRing((0.0,), (0.3,)), 2/3, 2/3), Gaussian(μas2rad(5.0))) gauss = Gaussian(μas2rad(20.0)) m87_model = ring + 0.1 * gauss ``` ### Create Sgr A* Style Model ```julia using Comrade, Gay gay_seed!(2024) # Sgr A* crescent with compact core crescent = ConcordanceCrescent(μas2rad(25.0), 0.9, 0.3, π/4) core = Gaussian(μas2rad(5.0)) sgra_model = crescent + 0.2 * shifted(core, μas2rad(3.0), μas2rad(-2.0)) ``` ### Pigeons.jl Integration ```julia using Pigeons, Comrade # Transform posterior for parallel tempering pt = pigeons( target = ascube(post), # Unit hypercube transformation reference = asflat(prior), # Flat reference distribution n_rounds = 15, n_chains = 24 ) # Extract samples samples = sample_array(pt) ``` ### Gay.jl REPL Commands ```julia # In Julia REPL with Gay.jl loaded using Gay # Set seed for reproducible colors gay_seed!(1069) # Create colored ring primitive ring = comrade_ring(1.0, 0.3) # Gets deterministic color # Show as colored S-expression sky_show(ring) # => "(ring 1.0 0.3)" with colored parentheses # Build and visualize full model model = comrade_model(seed=1069, style=:m87) comrade_show(model) # Prints colored sexp + ASCII render ``` ## Integration with Gay.jl/src/comrade.jl Reference implementation: `/Users/bob/worlds/b/bmorphism/Gay.jl/src/comrade.jl` Key functions: - `comrade_ring(r, w)` - Ring with deterministic color - `comrade_mring(r, α, β)` - MRing with Fourier coefficients - `comrade_gaussian(σx, σy)` - Gaussian primitive - `comrade_model(seed=42, style=:m87)` - High-level model builder - `sky_show(model)` - Colored S-expression display - `sky_render(model)` - ASCII intensity map ## Related Skills - `gay-julia` - Core Gay.jl integration - `pigeons-spi` - Parallel tempering patterns - `lispsyntax-acset` - S-expression ↔ ACSet bridge - `infinity-operads` - Dendroidal structure for model composition --- ## Autopoietic Marginalia > **The interaction IS the skill improving itself.** Every use of this skill is an opportunity for worlding: - **MEMORY** (-1): Record what was learned - **REMEMBERING** (0): Connect patterns to other skills - **WORLDING** (+1): Evolve the skill based on use *Add Interaction Exemplars here as the skill is used.* --- Source attribution: plurigrid Original project: https://github.com/plurigrid/asi/blob/293ce9f76e3abcd5ba18db284688bc0d9ac6691d/skills/comrade-vlbi/SKILL.md License: MIT License information: https://opensource.org/license/mit Original upstream instructions; downloaded from Mega AI Hub. ## Upstream license notice MIT License Copyright (c) 2025 SkillCreator.ai Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. # Mega AI Hub resource metadata Creator / publisher: plurigrid Original project: https://github.com/plurigrid/asi/blob/293ce9f76e3abcd5ba18db284688bc0d9ac6691d/skills/comrade-vlbi/SKILL.md Attribution basis: Source repository record Fields of work: Data & Analytics, Development & Engineering, Education & Research Roles: Data Scientist, ML / AI Engineer, Researcher Specialties: Frontend Tools: Gay.Jl Country applicability: Country not specified Classification basis: Source catalog labels Instruction SHA-256: 66f9d93fa9d386ba08fbeb367e31138e6438d229485a5080608eb677144910f1