Refactor README and scripts for Lagged Oil-Unemployment Chart

Update README.md to reflect new project focus on lagged oil and unemployment charting. Revise installation instructions, quickstart guide, and repository structure. Modify scripts for data fetching and plotting, and add a new SQLite database for storing FRED data. Introduce a startup script to streamline setup and execution.

scripts/lagged_oil_unrate_chart_styled.py

@@ -22,6 +22,8 @@ from pathlib import Path
 
 import matplotlib.dates as mdates
 import matplotlib.pyplot as plt
+import matplotlib.ticker as mticker
+import numpy as np
 import pandas as pd
 from dateutil.relativedelta import relativedelta
 import sqlite3
@@ -82,7 +84,7 @@ def plot_lagged(
     end_date: datetime,
     extend_years: int,
 ) -> None:
-    """Render the dual-axis chart."""
+    """Render the dual-axis chart with fixed scales and log ticks on oil."""
     oil_shifted = oil.shift(offset_months)
 
     fig, ax1 = plt.subplots(figsize=(14, 7))
@@ -102,11 +104,12 @@ def plot_lagged(
         color="#1f77b4",
     )
     ax1.set_ylabel("Unemployment rate (%)", fontsize=12)
-    ax1.set_ylim(0, unrate["value"].max() * 1.1)
+    ax1.set_ylim(3, 15)
+    ax1.yaxis.set_major_locator(mticker.MultipleLocator(2))
     ax1.yaxis.set_major_formatter("{x:.0f}%")
     ax1.grid(axis="y", linestyle="--", alpha=0.4)
 
-    # Right axis – shifted oil
+    # Right axis – shifted oil (log scale)
     ax2 = ax1.twinx()
     ax2.plot(
         oil_shifted.index,
@@ -118,10 +121,23 @@ def plot_lagged(
         color="#FF9900",
     )
     ax2.set_ylabel("Oil price (USD)", fontsize=12)
-    ax2.set_ylim(0, oil_shifted["value"].max() * 1.1)
-    ax2.yaxis.set_major_formatter("${x:,.0f}")
 
-    # X-axis
+    # Build doubling ticks from $3 upward
+    min_tick = 3
+    max_val = oil_shifted["value"].max() * 1.1
+    ticks = []
+    i = 0
+    while min_tick * 2**i < max_val:
+        ticks.append(min_tick * 2**i)
+        i += 1
+    ticks.append(min_tick * 2**i)
+
+    ax2.set_yscale("log")
+    ax2.set_ylim(min_tick, ticks[-1])
+    ax2.set_yticks(ticks)
+    ax2.yaxis.set_major_formatter("${x:.0f}")
+
+    # X-axis formatting
     ax1.set_xlim(start_date, end_date + relativedelta(years=extend_years))
     ax1.xaxis.set_major_locator(mdates.YearLocator(base=5))
     ax1.xaxis.set_minor_locator(mdates.YearLocator(1))
@@ -136,8 +152,8 @@ def plot_lagged(
     # Footnote
     foot = (
         f"Dates: {start_date.strftime('%Y')} through "
-        f"{unrate.index[-1].strftime('%d %b %Y')}.\n"
-        "Source: Local FRED snapshot (offline)."
+        f"{unrate.index[-1].strftime('%d %b %Y')}\."
+        "\nSource: Local FRED snapshot (offline)."
     )
     plt.annotate(
         foot,