feat(ggplot2): implement slope-basic

[github-actions]

Implementation: slope-basic - r/ggplot2

Implements the r/ggplot2 version of slope-basic.

File: plots/slope-basic/implementations/r/ggplot2.R

Parent Issue: #981

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

Light render (plot-light.png): Warm off-white background (#FAF8F1). Title "slope-basic · r · ggplot2 · anyplot.ai" in dark ink, top-left, clearly readable. Eight entities connected by slope lines between "Q1 2024" and "Q4 2024" (bold dark axis labels, no gridlines/y-ticks). 6 lines/points/labels in brand green (#009E73) for "Increased", 2 in matte red (#AE3030) for "Decreased" (Summit Pack, Peak Headlamp). Entity name + dollar-value labels sit at both endpoints, colored to match line direction, with no row overlaps. A bordered "Change" legend (Increased/Decreased) sits below the plot. All text is readable against the light background — no light-on-light issues.

Dark render (plot-dark.png): Warm near-black background (#1A1A17). Same title, now in light ink. Same green/red data colors and line positions as the light render — confirmed identical, only chrome (background, ink, legend frame) flipped. "Q1 2024"/"Q4 2024" and legend text render in white/soft-ink and are clearly legible. No dark-on-dark failures.

Both renders are theme-correct and fully legible.

Score: 87/100

Category	Score	Max
Visual Quality	28	30
Design Excellence	13	20
Spec Compliance	15	15
Data Quality	15	15
Code Quality	10	10
Library Mastery	6	10
Total	87	100

Visual Quality (28/30)

• VQ-01: Text Legibility (7/8)
• VQ-02: No Overlap (6/6)
• VQ-03: Element Visibility (6/6)
• VQ-04: Color Accessibility (1/2) - Red/green hue is the primary direction signal
• VQ-05: Layout & Canvas (4/4)
• VQ-06: Axis Labels & Title (2/2)
• VQ-07: Palette Compliance (2/2)

Design Excellence (13/20)

• DE-01: Aesthetic Sophistication (5/8) - Semantic color use, deliberate non-overlapping layout, currency-formatted labels
• DE-02: Visual Refinement (4/6) - Gridlines/ticks removed, generous whitespace, framed legend
• DE-03: Data Storytelling (4/6) - Color highlights the two decliners against six risers

Spec Compliance (15/15)

• SC-01: Plot Type (5/5)
• SC-02: Required Features (4/4)
• SC-03: Data Mapping (3/3)
• SC-04: Title & Legend (3/3)

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6)
• DQ-02: Realistic Context (5/5)
• DQ-03: Appropriate Scale (4/4)

Code Quality (10/10)

• CQ-01: KISS Structure (3/3)
• CQ-02: Reproducibility (2/2)
• CQ-03: Clean Imports (2/2)
• CQ-04: Code Elegance (2/2)
• CQ-05: Output & API (1/1)

Library Mastery (6/10)

• LM-01: Idiomatic Usage (4/5)
• LM-02: Distinctive Features (2/5) - Relies on hand-tuned data rather than a general-purpose collision-avoidance technique

Score Caps Applied

• None

Strengths

• Non-overlapping layout achieved through thoughtfully constructed Q1/Q4 values so every one of the 8 entities lands on its own row on both sides — an elegant solution to the classic slope-chart label-collision problem.
• Correct Imprint palette usage: brand green #009E73 for "Increased" and the semantic-anchor red #AE3030 for "Decreased", identical between light and dark renders.
• Idiomatic tidyverse data prep: pivot_longer for the wide-to-long reshape, scales::dollar() for currency-formatted endpoint labels.
• Minimal, purposeful chrome: gridlines/y-ticks removed since value labels carry the numeric information directly; legible legend and axis labels in both themes with no clipping.

Weaknesses

• Direction is encoded via a red/green hue distinction, which is not fully colorblind-safe alone; mitigated by the adjoining numeric labels but a secondary channel (dashed vs solid line, or an up/down glyph) would make it robust without requiring the reader to compare numbers.
• The non-overlapping layout depends on hand-picked Q1/Q4 values rather than a general-purpose technique (e.g. ggrepel::geom_text_repel); real-world data with closer values would likely overlap.
• Title occupies roughly 35% of plot width, below the ~50-70% guideline range — minor headroom to grow plot.title slightly for stronger hierarchy (polish only, not a hard requirement).

Issues Found

1. VQ-04 LOW: Red/green is the primary channel distinguishing Increased vs Decreased
   • Fix: Add a secondary encoding (e.g. linetype = direction, or a small ▲/▼ glyph next to endpoint labels) so direction is legible without relying on hue or reading the numbers
2. LM-02 LOW: Label-overlap avoidance relies on curated data rather than a robust technique
   • Fix: Consider ggrepel::geom_text_repel (or similar) so the approach generalizes to arbitrary real-world value distributions

AI Feedback for Next Attempt

Strong implementation overall — spec compliance, data quality, and code quality are all excellent. To push Design Excellence and Library Mastery further: add a secondary visual channel for direction (linetype or glyph) beyond color alone, and consider a robust label-collision technique (ggrepel) instead of relying on hand-picked data values that happen not to overlap.

Verdict: APPROVED

[github-actions]

🔧 Repair Attempt 1/4

Applied fixes based on AI review feedback.

Status: Repair completed, re-triggering review...

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🤖 impl-repair

[claude]

AI Review - Attempt 2/3

Image Description

Light render (plot-light.png): Warm off-white background (#FAF8F1). Title "slope-basic · r · ggplot2 · anyplot.ai" in dark ink, top-left, clearly readable. Eight entities connected by slope lines between "Q1 2024" and "Q4 2024" (bold dark axis labels, no gridlines/y-ticks). 6 lines/points/labels in brand green (#009E73) for "Increased", 2 in matte red (#AE3030) for "Decreased" (Summit Pack, Peak Headlamp). Entity name + dollar-value labels sit at both endpoints with no row overlaps. A bordered "Change" legend sits below the plot. All chrome text is readable against the light background. However, zoomed crops of the "Decreased" line (and its legend key) show a fully solid stroke with zero dash gaps despite scale_linetype_manual specifying "dashed", and no ▲/▼ glyph is visible above any point despite geom_text(aes(label = glyph), ...) in the code — both attempted secondary channels for direction are silently absent from the render.

Dark render (plot-dark.png): Warm near-black background (#1A1A17). Same title, now in light ink. Same green/red data colors and line positions as the light render — confirmed identical, only chrome (background, ink, legend frame) flipped. "Q1 2024"/"Q4 2024" and legend text render in white/soft-ink and are clearly legible, no dark-on-dark issues. Same as light: the "Decreased" line/legend-key crop is fully solid (no dashes) and no arrow glyphs render above any point.

Both renders are theme-correct and all chrome text is legible. The gap is content, not legibility: the two secondary visual channels this repair round added for direction (dashed linetype, ▲/▼ glyph) do not actually render in either theme.

Score: 85/100

Category	Score	Max
Visual Quality	28	30
Design Excellence	13	20
Spec Compliance	15	15
Data Quality	15	15
Code Quality	8	10
Library Mastery	6	10
Total	85	100

Visual Quality (28/30)

• VQ-01: Text Legibility (7/8)
• VQ-02: No Overlap (6/6)
• VQ-03: Element Visibility (6/6)
• VQ-04: Color Accessibility (1/2) - Attempted dashed-linetype + arrow-glyph secondary channels do not render (see Image Description); direction is still hue-only
• VQ-05: Layout & Canvas (4/4)
• VQ-06: Axis Labels & Title (2/2)
• VQ-07: Palette Compliance (2/2)

Design Excellence (13/20)

• DE-01: Aesthetic Sophistication (5/8) - Semantic color use, deliberate non-overlapping layout, currency-formatted labels
• DE-02: Visual Refinement (4/6) - Gridlines/ticks removed, generous whitespace, framed legend
• DE-03: Data Storytelling (4/6) - Color highlights the two decliners against six risers

Spec Compliance (15/15)

• SC-01: Plot Type (5/5)
• SC-02: Required Features (4/4)
• SC-03: Data Mapping (3/3)
• SC-04: Title & Legend (3/3)

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6)
• DQ-02: Realistic Context (5/5)
• DQ-03: Appropriate Scale (4/4)

Code Quality (8/10)

• CQ-01: KISS Structure (2/3) - Introduces a custom enforce_min_gap() helper with an explicit loop, deviating from the no-functions KISS structure that scored full marks in attempt 1
• CQ-02: Reproducibility (2/2)
• CQ-03: Clean Imports (2/2)
• CQ-04: Code Elegance (1/2) - Ships a dashed-linetype scale and glyph geom_text layer that don't visibly render — non-functional code shipped without verifying the actual rendered output
• CQ-05: Output & API (1/1)

Library Mastery (6/10)

• LM-01: Idiomatic Usage (4/5)
• LM-02: Distinctive Features (2/5) - enforce_min_gap() is generic R, not ggplot2-specific; the linetype+glyph combined-legend trick is a ggplot2-idiomatic pattern in principle but doesn't actually render

Score Caps Applied

• None

Strengths

• Non-overlapping layout is now driven by a general-purpose enforce_min_gap() function (pushes rows apart by a minimum spacing derived from the data range) rather than hand-picked values that merely happened not to collide — a real robustness improvement over attempt 1.
• Correct Imprint palette usage: brand green #009E73 for "Increased" and semantic-anchor red #AE3030 for "Decreased", identical between light and dark renders; both themes' chrome is theme-correct and fully legible.
• Idiomatic tidyverse data prep: pivot_longer(names_pattern = ...) for the wide-to-long reshape, scales::dollar() for currency-formatted endpoint labels.
• Minimal, purposeful chrome: gridlines/y-ticks removed since value labels carry the numeric information directly; legible legend and axis labels in both themes with no clipping.

Weaknesses

• VQ-04 fix did not actually render: this repair added scale_linetype_manual (dashed for "Decreased") and a geom_text ▲/▼ glyph layer intended to give direction a second visual channel beyond hue. Neither shows up in either theme — cropped, zoomed inspection of the "Decreased" line (both light and dark, including the legend key swatch) shows a fully solid stroke with zero dash gaps over 1000+ px, and no arrow glyph is visible above any point marker even at 4x zoom. Direction is still communicated by hue alone (mitigated only by the adjacent numeric labels), i.e. functionally unchanged from attempt 1's flagged issue.
• CQ-01 regression: a custom enforce_min_gap() helper function (with an explicit for-loop) was introduced this round, moving away from the "Imports → Data → Plot → Save, no functions/classes" KISS structure that scored full marks in attempt 1.
• Title occupies roughly 35% of plot width, below the ~50-70% guideline range — minor polish headroom, not a hard requirement.

Issues Found

1. VQ-04 LOW: dashed linetype + ▲/▼ glyph secondary channels do not render in either theme (confirmed via legend key and multiple point-level crops) — direction is still hue-only.
   • Fix: Verify the actual rendered PNG before relying on scale_linetype_manual; consider geom_point(shape = if_else(direction == "Increased", 24, 25)) (filled triangle-up/down point shapes, rendered as vector shapes rather than font glyphs) for a channel guaranteed to render regardless of font availability, or explicitly set a family = on geom_text() known to include U+25B2/U+25BC and confirm it renders in the CI font environment.
2. CQ-01 LOW: custom enforce_min_gap() helper function deviates from the no-functions KISS structure.
   • Fix: Either inline the gap-enforcement logic as a vectorized dplyr/base-R expression, or accept the minor structural cost since it demonstrably improves layout robustness — document the tradeoff if kept.

AI Feedback for Next Attempt

Score clears this round's bar, but the VQ-04 fix attempted in this repair (dashed linetype + ▲▼ glyphs) did not actually render — verify visually before resubmitting. Direction is currently distinguished by hue only, same as attempt 1. If this comes back for another repair pass, use filled triangle point shapes (up/down, geom_point(shape=24/25)) instead of text glyphs, since shapes render as vectors and don't depend on font glyph coverage, and double-check scale_linetype_manual is actually producing visible dashes at this linewidth before shipping.

Verdict: APPROVED