import matplotlib.pyplot as plt

def show_grid(grid, title=None, cmap='tab10', vmin=0, vmax=9):
    plt.figure(figsize=(3, 3))
    plt.imshow(grid, cmap=cmap, vmin=vmin, vmax=vmax)
    plt.colorbar(fraction=0.046, pad=0.04)
    if title:
        plt.title(title)
    plt.axis('off')
    plt.show()

def show_side_by_side(grids, titles, cmap='tab10', vmin=0, vmax=9):
    n = len(grids)
    plt.figure(figsize=(3 * n, 3))
    for i, (g, t) in enumerate(zip(grids, titles)):
        plt.subplot(1, n, i + 1)
        plt.imshow(g, cmap=cmap, vmin=vmin, vmax=vmax)
        plt.title(t)
        plt.axis('off')
    plt.tight_layout()
    plt.show()

def plot_sigma_trace(sigmas, title="σ trace"):
    plt.figure(figsize=(4, 3))
    plt.plot(range(len(sigmas)), sigmas, marker='o')
    plt.xlabel("Step")
    plt.ylabel("σ (L1 residue)")
    plt.title(title)
    plt.grid(True, alpha=0.3)
    plt.show()