{"spec_id":"scatter-lag","library":"plotnine","language":"python","code":"\"\"\" anyplot.ai\nscatter-lag: Lag Plot for Time Series Autocorrelation Diagnosis\nLibrary: plotnine 0.15.7 | Python 3.13.14\nQuality: 88/100 | Updated: 2026-06-24\n\"\"\"\n\nimport os\n\nimport numpy as np\nimport pandas as pd\nfrom plotnine import (\n    aes,\n    element_blank,\n    element_line,\n    element_rect,\n    element_text,\n    facet_wrap,\n    geom_abline,\n    geom_point,\n    geom_text,\n    ggplot,\n    labs,\n    scale_color_gradient,\n    theme,\n    theme_minimal,\n)\n\n\n# Theme tokens\nTHEME = os.getenv(\"ANYPLOT_THEME\", \"light\")\nPAGE_BG = \"#FAF8F1\" if THEME == \"light\" else \"#1A1A17\"\nELEVATED_BG = \"#FFFDF6\" if THEME == \"light\" else \"#242420\"\nINK = \"#1A1A17\" if THEME == \"light\" else \"#F0EFE8\"\nINK_SOFT = \"#4A4A44\" if THEME == \"light\" else \"#B8B7B0\"\nGRID = \"#D8D7D0\" if THEME == \"light\" else \"#3A3A36\"\n\n# Data — daily temperature readings with AR(1) autocorrelation (phi=0.85)\nnp.random.seed(42)\nn = 300\nphi = 0.85\nnoise = np.random.normal(0, 2.5, n)\ntemperatures = np.zeros(n)\ntemperatures[0] = 20 + noise[0]\nfor i in range(1, n):\n    temperatures[i] = (1 - phi) * 20 + phi * temperatures[i - 1] + noise[i]\n\n# Build lag dataframe for lags 1, 3, and 7\nlags = [1, 3, 7]\nrows = []\nfor lag in lags:\n    for i in range(n - lag):\n        rows.append(\n            {\n                \"temp_t\": temperatures[i],\n                \"temp_t_lag\": temperatures[i + lag],\n                \"day\": i,\n                \"lag\": f\"Lag = {lag} day{'s' if lag > 1 else ''}\",\n            }\n        )\ndf = pd.DataFrame(rows)\nlag_order = [f\"Lag = {k} day{'s' if k > 1 else ''}\" for k in lags]\ndf[\"lag\"] = pd.Categorical(df[\"lag\"], categories=lag_order, ordered=True)\n\n# Per-lag Pearson r annotations\nannot_rows = []\nfor lag in lags:\n    lag_label = f\"Lag = {lag} day{'s' if lag > 1 else ''}\"\n    sub = df[df[\"lag\"] == lag_label]\n    r = sub[\"temp_t\"].corr(sub[\"temp_t_lag\"])\n    x_rng = sub[\"temp_t\"].max() - sub[\"temp_t\"].min()\n    y_rng = sub[\"temp_t_lag\"].max() - sub[\"temp_t_lag\"].min()\n    annot_rows.append(\n        {\n            \"temp_t\": sub[\"temp_t\"].min() + 0.05 * x_rng,\n            \"temp_t_lag\": sub[\"temp_t_lag\"].max() - 0.08 * y_rng,\n            \"lag\": lag_label,\n            \"label\": f\"r = {r:.2f}\",\n        }\n    )\nannot_df = pd.DataFrame(annot_rows)\nannot_df[\"lag\"] = pd.Categorical(annot_df[\"lag\"], categories=lag_order, ordered=True)\n\n# Plot\nplot = (\n    ggplot(df, aes(x=\"temp_t\", y=\"temp_t_lag\", color=\"day\"))\n    + geom_abline(intercept=0, slope=1, color=INK_SOFT, linetype=\"dashed\", size=0.7)\n    + geom_point(size=2.0, alpha=0.45)\n    + geom_text(\n        data=annot_df,\n        mapping=aes(x=\"temp_t\", y=\"temp_t_lag\", label=\"label\"),\n        color=INK,\n        size=3,\n        ha=\"left\",\n        inherit_aes=False,\n    )\n    + facet_wrap(\"lag\", ncol=3)\n    + scale_color_gradient(low=\"#009E73\", high=\"#4467A3\", name=\"Day\")\n    + labs(\n        x=\"Temperature at Day t (°C)\",\n        y=\"Temperature at Day t+k (°C)\",\n        title=\"scatter-lag · python · plotnine · anyplot.ai\",\n    )\n    + theme_minimal()\n    + theme(\n        figure_size=(8, 4.5),\n        plot_background=element_rect(fill=PAGE_BG, color=PAGE_BG),\n        panel_background=element_rect(fill=PAGE_BG),\n        panel_border=element_blank(),\n        strip_background=element_rect(fill=ELEVATED_BG, color=INK_SOFT),\n        strip_text=element_text(color=INK, size=8, weight=\"bold\"),\n        panel_grid_major=element_line(color=GRID, size=0.4),\n        panel_grid_minor=element_blank(),\n        axis_ticks=element_blank(),\n        axis_title=element_text(color=INK, size=10),\n        axis_text=element_text(color=INK_SOFT, size=8),\n        plot_title=element_text(color=INK, size=12, weight=\"bold\"),\n        legend_background=element_rect(fill=ELEVATED_BG, color=INK_SOFT),\n        legend_text=element_text(color=INK_SOFT, size=8),\n        legend_title=element_text(color=INK, size=8),\n    )\n)\n\n# Save\nplot.save(f\"plot-{THEME}.png\", dpi=400, width=8, height=4.5, units=\"in\")\n"}