update(violin-basic): altair — comprehensive quality review

Comprehensive quality review improving code quality, data choice, visual design, spec compliance, and library feature usage.

Author: MarkusNeusinger

plots/violin-basic/implementations/altair.py

@@ -1,7 +1,7 @@
 """ pyplots.ai
 violin-basic: Basic Violin Plot
-Library: altair 6.0.0 | Python 3.13.11
-Quality: 92/100 | Created: 2025-12-23
+Library: altair 6.0.0 | Python 3.14.3
+Quality: /100 | Updated: 2026-02-21
 """
 
 import altair as alt
@@ -16,39 +16,34 @@
 
 for cat in categories:
     if cat == "Engineering":
-        # Higher salaries with moderate spread
         values = np.random.normal(92000, 16000, 150)
     elif cat == "Marketing":
-        # Mid-range salaries
         values = np.random.normal(70000, 13000, 150)
     elif cat == "Sales":
         # Bimodal: base salary + high performers with commissions
         values = np.concatenate([np.random.normal(50000, 8000, 75), np.random.normal(92000, 11000, 75)])
     else:  # Support
-        # Lower salary, tighter distribution
         values = np.random.normal(55000, 10000, 150)
 
     for v in values:
         data.append({"Department": cat, "Salary": v})
 
 df = pd.DataFrame(data)
 
-# Calculate statistics for quartile markers
+# Merge quartile statistics for layering
 stats = (
     df.groupby("Department")["Salary"]
     .agg(q1=lambda x: x.quantile(0.25), median=lambda x: x.quantile(0.5), q3=lambda x: x.quantile(0.75))
     .reset_index()
 )
+df = df.merge(stats, on="Department")
 
-# Merge stats for layering
-df_with_stats = df.merge(stats, on="Department")
-
-# Colors - Python palette
-colors = ["#306998", "#FFD43B", "#4B8BBE", "#FFE873"]
+# Colors - cohesive colorblind-safe palette starting with Python Blue
+colors = ["#306998", "#E5832D", "#4B8BBE", "#8B6C42"]
 color_scale = alt.Scale(domain=categories, range=colors)
 
 # Base chart
-base = alt.Chart(df_with_stats)
+base = alt.Chart(df)
 
 # Violin shape using kernel density transform
 violin = (
@@ -69,14 +64,17 @@
             axis=alt.Axis(labels=False, values=[0], grid=False, ticks=False),
         ),
         color=alt.Color("Department:N", scale=color_scale, legend=None),
+        tooltip=[alt.Tooltip("Department:N"), alt.Tooltip("Salary:Q", format="$,.0f")],
     )
 )
 
-# IQR rule (black vertical line)
-quartile_rule = base.mark_rule(color="black", strokeWidth=5).encode(y="q1:Q", y2="q3:Q")
+# IQR rule (dark line from Q1 to Q3)
+quartile_rule = base.mark_rule(color="#1a1a1a", strokeWidth=5).encode(y="q1:Q", y2="q3:Q")
 
-# Median point (white dot with black border)
-median_point = base.mark_point(color="white", size=250, filled=True, strokeWidth=3, stroke="black").encode(y="median:Q")
+# Median point (white dot with dark border)
+median_point = base.mark_point(color="white", size=250, filled=True, strokeWidth=3, stroke="#1a1a1a").encode(
+    y="median:Q", tooltip=[alt.Tooltip("Department:N"), alt.Tooltip("median:Q", title="Median Salary", format="$,.0f")]
+)
 
 # Combine layers and facet by department
 chart = (
@@ -92,7 +90,7 @@
     .properties(title=alt.Title("violin-basic · altair · pyplots.ai", fontSize=28, anchor="middle"))
     .configure_facet(spacing=20)
     .configure_view(stroke=None, continuousWidth=350, continuousHeight=750)
-    .configure_axis(labelFontSize=18, titleFontSize=22, gridOpacity=0.3, gridDash=[3, 3])
+    .configure_axis(labelFontSize=18, titleFontSize=22, gridOpacity=0.2, gridDash=[3, 3])
 )
 
 # Save outputs

plots/violin-basic/metadata/altair.yaml

@@ -1,16 +1,16 @@
 library: altair
 specification_id: violin-basic
 created: '2025-12-23T00:38:09Z'
-updated: '2025-12-23T00:42:01Z'
-generated_by: claude-opus-4-5-20251101
+updated: '2026-02-21T22:25:00+00:00'
+generated_by: claude-opus-4-6
 workflow_run: 20447779967
 issue: 0
-python_version: 3.13.11
-library_version: 6.0.0
+python_version: '3.14.3'
+library_version: '6.0.0'
 preview_url: https://storage.googleapis.com/pyplots-images/plots/violin-basic/altair/plot.png
 preview_thumb: https://storage.googleapis.com/pyplots-images/plots/violin-basic/altair/plot_thumb.png
 preview_html: https://storage.googleapis.com/pyplots-images/plots/violin-basic/altair/plot.html
-quality_score: 92
+quality_score: null
 impl_tags:
   dependencies: []
   techniques: