feat(letsplot): implement line-basic

Refactored to follow KISS style guidelines:
- Simple sequential script (no functions or classes)
- Uses example data from spec
- Proper 4800x2700 px output with scale=3
- Python Blue (#306998) color from style guide

Author: github-actions[bot]

plots/letsplot/line/line-basic/default.py

@@ -1,8 +1,6 @@
 """
-line-basic: Basic Line Chart
-Library: lets-plot
-
-A fundamental line chart that visualizes trends and patterns in data over a continuous axis.
+line-basic: Basic Line Plot
+Library: letsplot
 """
 
 import pandas as pd
@@ -20,147 +18,29 @@
     theme,
     theme_minimal,
 )
-from lets_plot.plot.core import PlotSpec
 
 
 LetsPlot.setup_html()
 
-
-def create_plot(
-    data: pd.DataFrame,
-    x: str,
-    y: str,
-    figsize: tuple[float, float] = (10, 6),
-    linewidth: float = 2.0,
-    color: str = "#306998",
-    alpha: float = 1.0,
-    marker: str | None = None,
-    marker_size: float = 6.0,
-    title: str | None = None,
-    xlabel: str | None = None,
-    ylabel: str | None = None,
-    linestyle: str = "solid",
-    grid: bool = True,
-    **kwargs,
-) -> PlotSpec:
-    """
-    Create a basic line chart connecting data points in sequence.
-
-    Args:
-        data: Input DataFrame containing the data to plot
-        x: Column name for x-axis values (typically numeric or ordered)
-        y: Column name for y-axis values (numeric)
-        figsize: Figure size as (width, height) in inches (used for aspect ratio)
-        linewidth: Width of the line in points
-        color: Line color (default: Python Blue from style guide)
-        alpha: Line transparency (0.0 to 1.0)
-        marker: Marker style for data points (e.g., 'o', 's', '^')
-        marker_size: Size of markers if enabled
-        title: Plot title (optional)
-        xlabel: X-axis label (defaults to column name if None)
-        ylabel: Y-axis label (defaults to column name if None)
-        linestyle: Line style ('solid', 'dashed', 'dotted', 'dotdash')
-        grid: Whether to show grid lines
-        **kwargs: Additional parameters
-
-    Returns:
-        lets-plot PlotSpec object
-
-    Raises:
-        ValueError: If data is empty
-        KeyError: If required columns are not found in data
-
-    Example:
-        >>> data = pd.DataFrame({
-        ...     'month': [1, 2, 3, 4, 5, 6],
-        ...     'sales': [100, 150, 130, 180, 200, 190]
-        ... })
-        >>> fig = create_plot(data, 'month', 'sales')
-    """
-    # Input validation
-    if data.empty:
-        raise ValueError("Data cannot be empty")
-
-    for col in [x, y]:
-        if col not in data.columns:
-            available = ", ".join(data.columns)
-            raise KeyError(f"Column '{col}' not found. Available: {available}")
-
-    # Set default labels to column names if not provided
-    x_label = xlabel if xlabel is not None else x
-    y_label = ylabel if ylabel is not None else y
-
-    # Sort data by x to ensure proper line connection
-    plot_data = data.sort_values(by=x).copy()
-
-    # Map linestyle aliases to lets-plot format
-    linetype_map = {
-        "-": "solid",
-        "--": "dashed",
-        "-.": "dotdash",
-        ":": "dotted",
-        "solid": "solid",
-        "dashed": "dashed",
-        "dotted": "dotted",
-        "dotdash": "dotdash",
-    }
-    linetype = linetype_map.get(linestyle, "solid")
-
-    # Create the base plot with line geometry
-    plot = (
-        ggplot(plot_data, aes(x=x, y=y))
-        + geom_line(color=color, size=linewidth, alpha=alpha, linetype=linetype)
-        + labs(x=x_label, y=y_label, title=title)
-        + theme_minimal()
-        + theme(
-            plot_title=element_text(size=20, face="bold"),
-            axis_title=element_text(size=20),
-            axis_text=element_text(size=16),
-            legend_text=element_text(size=16),
-            panel_grid_major=element_line(color="#CCCCCC", size=0.5) if grid else element_line(color="rgba(0,0,0,0)"),
-            panel_grid_minor=element_line(color="#EEEEEE", size=0.3) if grid else element_line(color="rgba(0,0,0,0)"),
-        )
-        + ggsize(1600, 900)  # Base size, scaled 3x on export to get 4800 x 2700
-    )
-
-    # Add markers if specified
-    if marker is not None:
-        # Map common marker styles to lets-plot shapes
-        marker_map = {
-            "o": 16,  # circle
-            "s": 15,  # square
-            "^": 17,  # triangle up
-            "v": 25,  # triangle down
-            "D": 18,  # diamond
-            "*": 8,  # asterisk
-        }
-        shape = marker_map.get(marker, 16)
-        plot = plot + geom_point(color=color, size=marker_size, alpha=alpha, shape=shape)
-
-    return plot
-
-
-if __name__ == "__main__":
-    # Sample data for testing
-    sample_data = pd.DataFrame(
-        {
-            "month": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12],
-            "sales": [120, 150, 170, 160, 190, 220, 240, 230, 210, 195, 180, 210],
-        }
-    )
-
-    # Create plot with markers
-    fig = create_plot(
-        sample_data,
-        "month",
-        "sales",
-        title="Monthly Sales Trend",
-        xlabel="Month",
-        ylabel="Sales ($K)",
-        marker="o",
-        linewidth=2.5,
+# Data
+data = pd.DataFrame({"time": [1, 2, 3, 4, 5, 6, 7], "value": [10, 15, 13, 18, 22, 19, 25]})
+
+# Plot
+plot = (
+    ggplot(data, aes(x="time", y="value"))
+    + geom_line(color="#306998", size=2, alpha=1.0)
+    + geom_point(color="#306998", size=4, alpha=1.0)
+    + labs(x="Time", y="Value", title="Basic Line Plot")
+    + theme_minimal()
+    + theme(
+        plot_title=element_text(size=20, face="bold"),
+        axis_title=element_text(size=20),
+        axis_text=element_text(size=16),
+        panel_grid_major=element_line(color="#CCCCCC", size=0.5),
+        panel_grid_minor=element_line(color="#EEEEEE", size=0.3),
     )
+    + ggsize(1600, 900)
+)
 
-    # Save - scale 3x to get 4800 x 2700 px
-    ggsave(fig, "plot.png", path=".", scale=3)
-    print("Plot saved to plot.png")
+# Save - scale 3x to get 4800 x 2700 px
+ggsave(plot, "plot.png", path=".", scale=3)