Add script to plot participant dataset availability matrix

Shows which participants have hyperface, budapest, and identity_decoding
data in a compact matrix visualization.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mvdoc

scripts/qa/qa-plot-participant-datasets.py

@@ -0,0 +1,82 @@
+#!/usr/bin/env python
+"""Plot a matrix showing which participants have data from each dataset.
+
+Creates a visualization with participants as rows and datasets (hyperface,
+budapest, identity-decoding) as columns.
+
+Examples:
+    python scripts/qa/qa-plot-participant-datasets.py
+"""
+
+import matplotlib.pyplot as plt
+import numpy as np
+import pandas as pd
+
+from hyperface.qa import create_qa_argument_parser, get_config
+
+
+def main():
+    parser = create_qa_argument_parser(
+        description="Plot participant dataset availability matrix.",
+        include_subjects=False,
+    )
+    args = parser.parse_args()
+    config = get_config(config_path=args.config, data_dir=args.data_dir)
+
+    # Load participants file
+    participants_file = config.paths.data_dir / "participants.tsv"
+    df = pd.read_csv(participants_file, sep="\t")
+
+    # Create binary matrix
+    n_participants = len(df)
+    datasets = ["hyperface", "budapest", "identity_decoding"]
+    matrix = np.zeros((n_participants, 3), dtype=int)
+
+    # All participants have hyperface
+    matrix[:, 0] = 1
+
+    # Convert Yes/No to 1/0
+    matrix[:, 1] = (df["budapest"] == "Yes").astype(int)
+    matrix[:, 2] = (df["identity_decoding"] == "Yes").astype(int)
+
+    # Create figure with square cells
+    fig, ax = plt.subplots(figsize=(2, n_participants * 0.25))
+
+    # Plot heatmap using pcolormesh for precise cell edges
+    cmap = plt.cm.colors.ListedColormap(["white", "tab:blue"])
+    ax.pcolormesh(
+        matrix,
+        cmap=cmap,
+        vmin=0,
+        vmax=1,
+        edgecolors="lightgray",
+        linewidth=0.3,
+    )
+    ax.set_aspect("equal")
+    ax.invert_yaxis()
+
+    # Labels
+    ax.set_xticks(np.arange(3) + 0.5)
+    ax.set_xticklabels(
+        ["hyperface", "budapest", "identity\ndecoding"], rotation=45, ha="left"
+    )
+    ax.xaxis.tick_top()
+    ax.set_yticks(np.arange(n_participants) + 0.5)
+    ax.set_yticklabels(df["participant_id"].str.replace("sub-", ""))
+
+    ax.set_ylabel("Participant")
+
+    plt.tight_layout()
+
+    # Save figure
+    output_dir = config.paths.qa_base_dir / "figures"
+    output_dir.mkdir(parents=True, exist_ok=True)
+    output_file = output_dir / "participant-dataset-matrix.png"
+    fig.savefig(output_file, dpi=600, bbox_inches="tight")
+    print(f"Saved figure to {output_file}")
+
+    plt.close(fig)
+
+
+if __name__ == "__main__":
+    main()