feat(highcharts): implement scatter-regression-lowess

plots/scatter-regression-lowess/implementations/python/highcharts.py

@@ -1,9 +1,10 @@
-""" pyplots.ai
+""" anyplot.ai
 scatter-regression-lowess: Scatter Plot with LOWESS Regression
-Library: highcharts unknown | Python 3.13.11
-Quality: 91/100 | Created: 2025-12-30
+Library: highcharts unknown | Python 3.13.13
+Quality: 90/100 | Updated: 2026-05-14
 """
 
+import os
 import tempfile
 import time
 import urllib.request
@@ -18,37 +19,41 @@
 from selenium.webdriver.chrome.options import Options
 
 
+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 position 1
+ACCENT = "#D55E00"  # Okabe-Ito position 2 for LOWESS curve
+
+
 def lowess(x, y, frac=0.3):
     """Simple LOWESS implementation using tricube weighting."""
     n = len(x)
-    k = int(np.ceil(frac * n))  # Number of neighbors to use
+    k = int(np.ceil(frac * n))
     y_smooth = np.zeros(n)
     sorted_idx = np.argsort(x)
     x_sorted = x[sorted_idx]
     y_sorted = y[sorted_idx]
 
     for i in range(n):
-        # Calculate distances to all points
         distances = np.abs(x_sorted - x_sorted[i])
-        # Find k nearest neighbors
         nearest_idx = np.argsort(distances)[:k]
-        # Maximum distance among neighbors
         max_dist = distances[nearest_idx[-1]]
         if max_dist == 0:
             max_dist = 1.0
-        # Tricube weights
         u = distances[nearest_idx] / max_dist
         weights = (1 - u**3) ** 3
-        # Weighted linear regression
         x_local = x_sorted[nearest_idx]
         y_local = y_sorted[nearest_idx]
-        # Weighted least squares
         w_sum = np.sum(weights)
         wx_sum = np.sum(weights * x_local)
         wy_sum = np.sum(weights * y_local)
         wxx_sum = np.sum(weights * x_local * x_local)
         wxy_sum = np.sum(weights * x_local * y_local)
-        # Solve for slope and intercept
         denom = w_sum * wxx_sum - wx_sum**2
         if abs(denom) < 1e-10:
             y_smooth[i] = wy_sum / w_sum if w_sum > 0 else y_sorted[i]
@@ -57,23 +62,21 @@ def lowess(x, y, frac=0.3):
             intercept = (wy_sum - slope * wx_sum) / w_sum
             y_smooth[i] = slope * x_sorted[i] + intercept
 
-    # Return in original order
     result = np.zeros(n)
     result[sorted_idx] = y_smooth
     return x, result
 
 
-# Data - Generate complex non-linear relationship
+# Data - Non-linear relationship
 np.random.seed(42)
 n_points = 200
 x = np.linspace(0, 10, n_points)
-# Create a complex non-linear pattern: sine wave + quadratic + noise
 y = 3 * np.sin(x * 1.2) + 0.3 * x**2 - 0.5 * x + np.random.normal(0, 1.5, n_points)
 
 # Compute LOWESS regression curve
 x_lowess, y_lowess = lowess(x, y, frac=0.3)
 
-# Create chart with container
+# Chart setup
 chart = Chart(container="container")
 chart.options = HighchartsOptions()
 
@@ -82,42 +85,51 @@ def lowess(x, y, frac=0.3):
     "type": "scatter",
     "width": 4800,
     "height": 2700,
-    "backgroundColor": "#ffffff",
-    "marginBottom": 250,
-    "marginLeft": 150,
+    "backgroundColor": PAGE_BG,
+    "marginBottom": 200,
+    "marginLeft": 180,
     "spacingTop": 60,
     "spacingRight": 100,
 }
 
-# Title
+# Title and subtitle
 chart.options.title = {
-    "text": "scatter-regression-lowess · highcharts · pyplots.ai",
-    "style": {"fontSize": "48px", "fontWeight": "bold"},
+    "text": "scatter-regression-lowess · highcharts · anyplot.ai",
+    "style": {"fontSize": "28px", "fontWeight": "bold", "color": INK},
 }
 
-# Subtitle with context
-chart.options.subtitle = {"text": "Non-linear Trend with LOWESS Smoothing (frac=0.3)", "style": {"fontSize": "32px"}}
+chart.options.subtitle = {
+    "text": "Non-linear Relationship with LOWESS Smoothing",
+    "style": {"fontSize": "22px", "color": INK_SOFT},
+}
 
 # X-axis configuration
 chart.options.x_axis = {
-    "title": {"text": "X Value", "style": {"fontSize": "36px"}},
-    "labels": {"style": {"fontSize": "28px"}},
+    "title": {"text": "Input Variable", "style": {"fontSize": "22px", "color": INK}},
+    "labels": {"style": {"fontSize": "18px", "color": INK_SOFT}},
+    "lineColor": INK_SOFT,
+    "tickColor": INK_SOFT,
+    "gridLineColor": GRID,
     "gridLineWidth": 1,
-    "gridLineColor": "rgba(0, 0, 0, 0.1)",
 }
 
 # Y-axis configuration
 chart.options.y_axis = {
-    "title": {"text": "Y Value", "style": {"fontSize": "36px"}},
-    "labels": {"style": {"fontSize": "28px"}},
+    "title": {"text": "Output Variable", "style": {"fontSize": "22px", "color": INK}},
+    "labels": {"style": {"fontSize": "18px", "color": INK_SOFT}},
+    "lineColor": INK_SOFT,
+    "tickColor": INK_SOFT,
+    "gridLineColor": GRID,
     "gridLineWidth": 1,
-    "gridLineColor": "rgba(0, 0, 0, 0.1)",
 }
 
 # Legend
 chart.options.legend = {
     "enabled": True,
-    "itemStyle": {"fontSize": "28px"},
+    "itemStyle": {"fontSize": "18px", "color": INK_SOFT},
+    "backgroundColor": ELEVATED_BG,
+    "borderColor": INK_SOFT,
+    "borderWidth": 1,
     "align": "right",
     "verticalAlign": "top",
     "layout": "vertical",
@@ -127,32 +139,47 @@ def lowess(x, y, frac=0.3):
 
 # Plot options
 chart.options.plot_options = {
-    "scatter": {
-        "marker": {"radius": 10, "fillColor": "rgba(48, 105, 152, 0.6)", "lineWidth": 1, "lineColor": "#306998"}
-    },
+    "scatter": {"marker": {"radius": 8, "fillColor": BRAND, "lineWidth": 1, "lineColor": PAGE_BG}},
     "spline": {"marker": {"enabled": False}, "lineWidth": 5},
 }
 
 # Add scatter series (data points)
 scatter_series = ScatterSeries()
 scatter_series.name = "Data Points"
-scatter_series.data = [[float(xi), float(yi)] for xi, yi in zip(x, y, strict=True)]
-scatter_series.color = "#306998"
+scatter_series.data = [[float(xi), float(yi)] for xi, yi in zip(x, y, strict=False)]
+scatter_series.color = BRAND
+scatter_series.marker = {"radius": 8, "fillColor": BRAND, "lineWidth": 1, "lineColor": PAGE_BG}
 chart.add_series(scatter_series)
 
 # Add LOWESS curve as spline series
 lowess_series = SplineSeries()
 lowess_series.name = "LOWESS Curve"
-lowess_series.data = [[float(xi), float(yi)] for xi, yi in zip(x_lowess, y_lowess, strict=True)]
-lowess_series.color = "#FFD43B"
+lowess_series.data = [[float(xi), float(yi)] for xi, yi in zip(x_lowess, y_lowess, strict=False)]
+lowess_series.color = ACCENT
 lowess_series.marker = {"enabled": False}
-lowess_series.line_width = 6
+lowess_series.line_width = 5
 chart.add_series(lowess_series)
 
 # Download Highcharts JS for inline embedding
 highcharts_url = "https://code.highcharts.com/highcharts.js"
-with urllib.request.urlopen(highcharts_url, timeout=30) as response:
-    highcharts_js = response.read().decode("utf-8")
+req = urllib.request.Request(
+    highcharts_url,
+    headers={
+        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
+        "Accept": "*/*",
+        "Accept-Language": "en-US,en;q=0.9",
+        "Referer": "https://www.highcharts.com/",
+    },
+)
+try:
+    with urllib.request.urlopen(req, timeout=30) as response:
+        highcharts_js = response.read().decode("utf-8")
+except urllib.error.HTTPError as e:
+    import sys
+
+    print(f"ERROR: Failed to download Highcharts JS: {e}", file=sys.stderr)
+    print(f"URL: {highcharts_url}", file=sys.stderr)
+    sys.exit(1)
 
 # Generate HTML with inline scripts
 html_str = chart.to_js_literal()
@@ -162,21 +189,21 @@ def lowess(x, y, frac=0.3):
     <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 HTML artifact
+with open(f"plot-{THEME}.html", "w", encoding="utf-8") as f:
+    f.write(html_content)
+
 # Write temp HTML and take screenshot
 with tempfile.NamedTemporaryFile(mode="w", suffix=".html", delete=False, encoding="utf-8") as f:
     f.write(html_content)
     temp_path = f.name
 
-# Also save HTML for interactive version
-with open("plot.html", "w", encoding="utf-8") as f:
-    f.write(html_content)
-
 # Configure Chrome for headless screenshot
 chrome_options = Options()
 chrome_options.add_argument("--headless")
@@ -187,8 +214,8 @@ def lowess(x, y, frac=0.3):
 
 driver = webdriver.Chrome(options=chrome_options)
 driver.get(f"file://{temp_path}")
-time.sleep(5)  # Wait for chart to render
-driver.save_screenshot("plot.png")
+time.sleep(5)
+driver.save_screenshot(f"plot-{THEME}.png")
 driver.quit()
 
 # Clean up temp file