feat(highcharts): implement andrews-curves (#6826)

## Implementation: `andrews-curves` - python/highcharts

Implements the **python/highcharts** version of `andrews-curves`.

**File:** `plots/andrews-curves/implementations/python/highcharts.py`

**Parent Issue:** #2859

---
:robot: *[impl-generate
workflow](https://github.com/MarkusNeusinger/anyplot/actions/runs/25919432228)*

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Markus Neusinger <2921697+MarkusNeusinger@users.noreply.github.com>

Author: github-actions[bot]

plots/andrews-curves/implementations/python/highcharts.py

@@ -1,9 +1,10 @@
-""" pyplots.ai
+""" anyplot.ai
 andrews-curves: Andrews Curves for Multivariate Data
-Library: highcharts unknown | Python 3.13.11
-Quality: 92/100 | Created: 2025-12-31
+Library: highcharts unknown | Python 3.13.13
+Quality: 83/100 | Updated: 2026-05-15
 """
 
+import os
 import tempfile
 import time
 import urllib.request
@@ -12,25 +13,32 @@
 import numpy as np
 from highcharts_core.chart import Chart
 from highcharts_core.options import HighchartsOptions
-from highcharts_core.options.series.area import LineSeries
+from highcharts_core.options.series.spline import SplineSeries
 from selenium import webdriver
 from selenium.webdriver.chrome.options import Options
 from sklearn.datasets import load_iris
 from sklearn.preprocessing import StandardScaler
 
 
-# Data - Iris dataset normalized
+THEME = os.getenv("ANYPLOT_THEME", "light")
+PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
+ELEVATED_BG = "#FFFDF6" if THEME == "light" else "#242420"
+INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
+INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"
+GRID = "rgba(26,26,23,0.10)" if THEME == "light" else "rgba(240,239,232,0.10)"
+
+BRAND = "#009E73"
+OKABE_ITO = ["#009E73", "#D55E00", "#0072B2"]
+
 iris = load_iris()
 X = StandardScaler().fit_transform(iris.data)
 y = iris.target
 species_names = ["Setosa", "Versicolor", "Virginica"]
 
-# Andrews curve transformation: f(t) = x1/sqrt(2) + x2*sin(t) + x3*cos(t) + x4*sin(2t) + ...
 t = np.linspace(-np.pi, np.pi, 200)
 
 
 def andrews_curve(x, t):
-    """Transform multivariate observation to Andrews curve"""
     n = len(x)
     result = x[0] / np.sqrt(2)
     for i in range(1, n):
@@ -41,77 +49,67 @@ def andrews_curve(x, t):
     return result
 
 
-# Create chart
 chart = Chart(container="container")
 chart.options = HighchartsOptions()
 
-# Chart settings
 chart.options.chart = {
     "type": "line",
     "width": 4800,
     "height": 2700,
-    "backgroundColor": "#ffffff",
+    "backgroundColor": PAGE_BG,
     "marginBottom": 180,
     "marginTop": 120,
     "marginLeft": 150,
     "marginRight": 100,
 }
 
-# Title
 chart.options.title = {
-    "text": "Iris Species · andrews-curves · highcharts · pyplots.ai",
-    "style": {"fontSize": "56px", "fontWeight": "bold"},
-    "y": 60,
+    "text": "andrews-curves · highcharts · anyplot.ai",
+    "style": {"fontSize": "28px", "color": INK},
+    "y": 30,
 }
 
-# Axes
 chart.options.x_axis = {
-    "title": {"text": "t (radians)", "style": {"fontSize": "40px"}, "margin": 30},
-    "labels": {"style": {"fontSize": "32px"}, "y": 40},
-    "gridLineWidth": 1,
-    "gridLineColor": "rgba(0,0,0,0.15)",
+    "title": {"text": "t (radians)", "style": {"fontSize": "22px", "color": INK}},
+    "labels": {"style": {"fontSize": "18px", "color": INK_SOFT}},
+    "lineColor": INK_SOFT,
+    "tickColor": INK_SOFT,
+    "gridLineColor": GRID,
     "tickInterval": 1,
     "min": -3.15,
     "max": 3.15,
 }
 
 chart.options.y_axis = {
-    "title": {"text": "f(t)", "style": {"fontSize": "40px"}, "margin": 30},
-    "labels": {"style": {"fontSize": "32px"}, "x": -15},
-    "gridLineWidth": 1,
-    "gridLineColor": "rgba(0,0,0,0.15)",
+    "title": {"text": "f(t)", "style": {"fontSize": "22px", "color": INK}},
+    "labels": {"style": {"fontSize": "18px", "color": INK_SOFT}},
+    "lineColor": INK_SOFT,
+    "tickColor": INK_SOFT,
+    "gridLineColor": GRID,
     "tickInterval": 1,
 }
 
-# Colors for species (colorblind-safe)
-colors = ["#306998", "#FFD43B", "#9467BD"]
-
-# Legend styling - positioned inside chart area to avoid clipping
 chart.options.legend = {
     "enabled": True,
-    "itemStyle": {"fontSize": "36px", "fontWeight": "bold"},
-    "symbolWidth": 60,
-    "symbolHeight": 4,
+    "itemStyle": {"fontSize": "18px", "color": INK_SOFT},
+    "symbolWidth": 30,
+    "symbolHeight": 2,
     "align": "right",
     "verticalAlign": "top",
     "layout": "vertical",
     "x": -50,
-    "y": 80,
-    "itemDistance": 20,
-    "itemMarginTop": 10,
-    "backgroundColor": "rgba(255,255,255,0.9)",
+    "y": 50,
+    "backgroundColor": ELEVATED_BG,
     "borderWidth": 1,
-    "borderColor": "#cccccc",
+    "borderColor": INK_SOFT,
     "padding": 15,
 }
 
-# Plot options for transparency
 chart.options.plot_options = {
     "line": {"lineWidth": 3, "marker": {"enabled": False}, "animation": False},
     "series": {"animation": False},
 }
 
-# Generate curves for each observation (sample 20 per species for clarity)
 np.random.seed(42)
 samples_per_species = 20
 
@@ -124,36 +122,36 @@ def andrews_curve(x, t):
         curve_values = andrews_curve(species_X[idx], t)
         data_points = [[float(t[j]), float(curve_values[j])] for j in range(len(t))]
 
-        series = LineSeries()
+        series = SplineSeries()
         series.data = data_points
         series.name = species_names[species_idx]
-        series.color = colors[species_idx]
+        series.color = OKABE_ITO[species_idx]
         series.opacity = 0.5
-        series.show_in_legend = i == 0  # Only show first curve in legend
+        series.show_in_legend = i == 0
         series.line_width = 2
 
         chart.add_series(series)
 
-# Download Highcharts JS
-highcharts_url = "https://code.highcharts.com/highcharts.js"
+highcharts_url = "https://cdn.jsdelivr.net/npm/highcharts@latest/highcharts.js"
 with urllib.request.urlopen(highcharts_url, timeout=30) as response:
     highcharts_js = response.read().decode("utf-8")
 
-# Generate HTML with inline script
 html_str = chart.to_js_literal()
 html_content = f"""<!DOCTYPE html>
 <html>
 <head>
     <meta charset="utf-8">
     <script>{highcharts_js}</script>
 </head>
-<body style="margin:0;">
+<body style="margin:0; background:{PAGE_BG};">
     <div id="container" style="width: 4800px; height: 2700px;"></div>
     <script>{html_str}</script>
 </body>
 </html>"""
 
-# Write temp HTML and capture screenshot
+with open(f"plot-{THEME}.html", "w", encoding="utf-8") as f:
+    f.write(html_content)
+
 with tempfile.NamedTemporaryFile(mode="w", suffix=".html", delete=False, encoding="utf-8") as f:
     f.write(html_content)
     temp_path = f.name
@@ -163,19 +161,12 @@ def andrews_curve(x, t):
 chrome_options.add_argument("--no-sandbox")
 chrome_options.add_argument("--disable-dev-shm-usage")
 chrome_options.add_argument("--disable-gpu")
-chrome_options.add_argument("--window-size=4900,2800")
+chrome_options.add_argument("--window-size=4800,2700")
 
 driver = webdriver.Chrome(options=chrome_options)
 driver.get(f"file://{temp_path}")
 time.sleep(5)
-
-# Screenshot the chart element for exact dimensions
-container = driver.find_element("id", "container")
-container.screenshot("plot.png")
+driver.save_screenshot(f"plot-{THEME}.png")
 driver.quit()
 
 Path(temp_path).unlink()
-
-# Also save HTML for interactive version
-with open("plot.html", "w", encoding="utf-8") as f:
-    f.write(html_content)