waterrocketpy.visualization.plot_flight_data

Comprehensive flight data visualization script for water rocket simulation. Creates multiple organized plots showing all aspects of the rocket's flight performance.

add_phase_backgrounds(ax, phases, alpha=0.1)

Add colored backgrounds to distinguish flight phases.

Source code in waterrocketpy/visualization/plot_flight_data.py

def add_phase_backgrounds(ax, phases, alpha=0.1):
    """Add colored backgrounds to distinguish flight phases."""
    colors = ['lightblue', 'lightgreen', 'lightyellow', 'lightcoral']
    labels = ['Water Phase', 'Air Phase', 'Coasting Up', 'Descent']

    # Get axis limits
    ylim = ax.get_ylim()
    height = ylim[1] - ylim[0]

    times = [0, phases['water_end'], phases['air_end'], 
             phases['apogee_time'], phases['flight_end']]

    for i in range(len(times)-1):
        if times[i+1] > times[i]:  # Only add if phase exists
            width = times[i+1] - times[i]
            if width > 0:
                rect = patches.Rectangle(
                    (times[i], ylim[0]), width, height,
                    linewidth=0, edgecolor='none',
                    facecolor=colors[min(i, len(colors)-1)],
                    alpha=alpha, zorder=0
                )
                ax.add_patch(rect)

create_summary_table(flight_data, phases)

Create a summary table of key flight parameters.

Source code in waterrocketpy/visualization/plot_flight_data.py

def create_summary_table(flight_data, phases):
    """Create a summary table of key flight parameters."""
    summary_data = {
        'Flight Performance': {
            'Maximum Altitude': f"{flight_data.max_altitude:.2f} m",
            'Maximum Velocity': f"{flight_data.max_velocity:.2f} m/s",
            'Total Flight Time': f"{flight_data.flight_time:.2f} s",
            'Time to Apogee': f"{phases['apogee_time']:.2f} s"
        },
        'Phase Durations': {
            'Water Phase': f"{phases['water_end']:.2f} s",
            'Air Phase': f"{phases['air_end'] - phases['water_end']:.2f} s" if phases['air_end'] > phases['water_end'] else "0.00 s",
            'Coasting Phase': f"{phases['flight_end'] - phases['air_end']:.2f} s" if phases['flight_end'] > phases['air_end'] else f"{phases['flight_end'] - phases['water_end']:.2f} s"
        },
        'Initial Conditions': {
            'Initial Water Mass': f"{flight_data.water_mass[0]*1000:.1f} g",
            'Initial Air Mass': f"{flight_data.air_mass[0]*1000:.1f} g",
            'Initial Pressure': f"{flight_data.pressure[0]/1e5:.2f} bar",
            'Initial Temperature': f"{flight_data.air_temperature[0]:.1f} K"
        }
    }

    return summary_data

identify_flight_phases(flight_data)

Identify the different phases of flight for visualization.

Returns:

Type	Description
dict	Phase boundaries and information

Source code in waterrocketpy/visualization/plot_flight_data.py

def identify_flight_phases(flight_data):
    """
    Identify the different phases of flight for visualization.

    Returns:
        dict: Phase boundaries and information
    """
    phases = {
        'water_end': flight_data.water_depletion_time,
        'air_end': flight_data.air_depletion_time,
        'flight_end': flight_data.flight_time
    }

    # Find apogee (maximum altitude)
    apogee_idx = np.argmax(flight_data.altitude)
    phases['apogee_time'] = flight_data.time[apogee_idx]
    phases['apogee_altitude'] = flight_data.max_altitude

    return phases

main()

Main function to run simulation and create all plots.

Source code in waterrocketpy/visualization/plot_flight_data.py

def main():
    """Main function to run simulation and create all plots."""
    print("Water Rocket Flight Data Visualization")
    print("=" * 50)

    # Setup plotting style
    setup_plot_style()

    try:
        # Create and run simulation
        print("1. Creating standard rocket...")
        rocket = create_standard_rocket()
        print(f"   ✓ Rocket created: {rocket.name}")

        print("2. Setting up simulation...")
        builder = RocketBuilder.from_dict(rocket.__dict__)
        sim_params = builder.to_simulation_params()

        simulator = WaterRocketSimulator()
        sim_settings = {"max_time": 100.0, "time_step": 0.01, "solver": "RK45"}

        print("3. Running simulation...")
        flight_data = simulator.simulate(sim_params, sim_settings)
        print(f"   ✓ Simulation completed! {len(flight_data.time)} data points generated")

        # Identify flight phases
        print("4. Analyzing flight phases...")
        phases = identify_flight_phases(flight_data)

        # Print summary
        print_flight_summary(flight_data, phases)

        # Create all plots
        print("5. Generating plots...")

        figs = []

        print("   - Trajectory and velocity plots...")
        figs.append(plot_trajectory_and_velocity(flight_data, phases))

        print("   - Forces and acceleration plots...")
        figs.append(plot_forces_and_acceleration(flight_data, phases))

        print("   - Propellant and pressure plots...")
        figs.append(plot_propellant_and_pressure(flight_data, phases))

        print("   - Exhaust properties plots...")
        figs.append(plot_exhaust_properties(flight_data, phases))

        print("   - Air exit conditions plots...")
        figs.append(plot_air_exit_conditions(flight_data, phases))

        # Show all plots
        print("6. Displaying plots...")
        plt.show()

        print("✓ All plots generated successfully!")

    except Exception as e:
        print(f"✗ Error: {e}")
        import traceback
        traceback.print_exc()

plot_air_exit_conditions(flight_data, phases)

Plot air and water exit conditions and internal bottle air properties.

Source code in waterrocketpy/visualization/plot_flight_data.py

def plot_air_exit_conditions(flight_data, phases):
    """Plot air and water exit conditions and internal bottle air properties."""
    fig, (ax1, ax2, ax3) = plt.subplots(3, 1, figsize=(12, 9))

    # Time masks
    air_phase_mask = (flight_data.time >= phases['water_end']) & (flight_data.time <= phases['air_end'])
    water_phase_mask = (flight_data.time >= 0) & (flight_data.time <= phases['water_end'])
    combine_mask = air_phase_mask | water_phase_mask

    if not np.any(air_phase_mask):
        ax1.text(0.5, 0.5, 'No air phase detected', ha='center', va='center', transform=ax1.transAxes)
        ax2.text(0.5, 0.5, 'No air phase detected', ha='center', va='center', transform=ax2.transAxes)
        ax3.text(0.5, 0.5, 'No air phase detected', ha='center', va='center', transform=ax3.transAxes)
    else:
        thrust_time = flight_data.time[combine_mask]

        # === 1. PRESSURE ===
        air_exit_pressure = np.nan_to_num(flight_data.air_exit_pressure[combine_mask], ATMOSPHERIC_PRESSURE) / 1e5
        internal_pressure = flight_data.pressure[combine_mask] / 1e5

        ax1.plot(thrust_time, air_exit_pressure, color='purple', linewidth=2, label='Air exit pressure')
        ax1.plot(thrust_time, internal_pressure, color='blue', linestyle='--', linewidth=2, label='Internal pressure')
        ax1.axhline(ATMOSPHERIC_PRESSURE / 1e5, color='gray', linestyle=':', alpha=0.7, label='Atmospheric pressure')
        ax1.set_ylabel('Pressure (bar)')
        ax1.set_title('Air Exit and Internal Conditions')
        ax1.grid(True, alpha=0.3)
        ax1.legend()

        # === 2. TEMPERATURE ===
        air_exit_temp = np.nan_to_num(flight_data.air_exit_temperature[combine_mask], INITIAL_TEMPERATURE)
        internal_temp = flight_data.air_temperature[combine_mask]

        ax2.plot(thrust_time, air_exit_temp, color='orange', linewidth=2, label='Air exit temperature')
        ax2.plot(thrust_time, internal_temp, color='red', linestyle='--', linewidth=2, label='Internal temperature')
        ax2.axhline(INITIAL_TEMPERATURE, color='gray', linestyle=':', alpha=0.7, label='Initial temperature')
        ax2.set_ylabel('Temperature (K)')
        ax2.grid(True, alpha=0.3)
        ax2.legend()

        # === 3. EXHAUST VELOCITY ===
        water_velocity = np.nan_to_num(flight_data.water_exhaust_speed[combine_mask], 0.0)
        air_velocity = np.nan_to_num(flight_data.air_exhaust_speed[combine_mask], 0.0)

        ax3.plot(thrust_time, water_velocity, color='blue', linewidth=2, label='Water exhaust velocity')
        ax3.plot(thrust_time, air_velocity, color='green', linewidth=2, label='Air exhaust velocity')
        ax3.set_xlabel('Time (s)')
        ax3.set_ylabel('Exhaust Velocity (m/s)')
        ax3.grid(True, alpha=0.3)
        ax3.legend()

    plt.tight_layout()
    return fig

plot_exhaust_properties(flight_data, phases)

Plot exhaust velocities and mass flow rates.

Source code in waterrocketpy/visualization/plot_flight_data.py

def plot_exhaust_properties(flight_data, phases):
    """Plot exhaust velocities and mass flow rates."""
    fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(12, 8))

    # Exhaust velocities
    # Handle None values by replacing with 0
    water_exhaust = np.nan_to_num(flight_data.water_exhaust_speed, 0)
    air_exhaust = np.nan_to_num(flight_data.air_exhaust_speed, 0)

    ax1.plot(flight_data.time, water_exhaust, 'b-', linewidth=2, label='Water exhaust speed')
    ax1.plot(flight_data.time, air_exhaust, 'g-', linewidth=2, label='Air exhaust speed')

    add_phase_backgrounds(ax1, phases)
    ax1.axvline(phases['water_end'], color='red', linestyle='--', alpha=0.7)
    ax1.axvline(phases['air_end'], color='orange', linestyle='--', alpha=0.7)

    ax1.set_ylabel('Exhaust Speed (m/s)')
    ax1.set_title('Exhaust Velocities')
    ax1.grid(True, alpha=0.3)
    ax1.legend()

    # Mass flow rates
    water_flow = np.nan_to_num(flight_data.water_mass_flow_rate, 0) * 1000  # Convert to g/s
    air_flow = np.nan_to_num(flight_data.air_mass_flow_rate, 0) * 1000

    ax2.plot(flight_data.time, -water_flow, 'b-', linewidth=2, label='Water flow rate')  # Negative because it's outflow
    ax2.plot(flight_data.time, -air_flow, 'g-', linewidth=2, label='Air flow rate')

    add_phase_backgrounds(ax2, phases)
    ax2.axvline(phases['water_end'], color='red', linestyle='--', alpha=0.7)
    ax2.axvline(phases['air_end'], color='orange', linestyle='--', alpha=0.7)

    ax2.set_xlabel('Time (s)')
    ax2.set_ylabel('Mass Flow Rate (g/s)')
    ax2.set_title('Propellant Mass Flow Rates')
    ax2.grid(True, alpha=0.3)
    ax2.legend()

    plt.tight_layout()
    return fig

plot_forces_and_acceleration(flight_data, phases)

Plot forces and acceleration.

Source code in waterrocketpy/visualization/plot_flight_data.py

def plot_forces_and_acceleration(flight_data, phases):
    """Plot forces and acceleration."""
    fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(12, 8))

    # Forces plot
    ax1.plot(flight_data.time, flight_data.thrust, 'g-', linewidth=2, label='Thrust')
    ax1.plot(flight_data.time, flight_data.drag, 'r-', linewidth=2, label='Drag')

    # Calculate weight (assuming constant during powered flight)
    # Weight changes as propellant is expelled
    total_mass = flight_data.water_mass + flight_data.air_mass + 0.15  # Assuming 0.15kg empty mass
    weight = total_mass * 9.81
    ax1.plot(flight_data.time, weight, 'k--', linewidth=1.5, label='Weight', alpha=0.7)

    add_phase_backgrounds(ax1, phases)
    ax1.axvline(phases['water_end'], color='red', linestyle='--', alpha=0.7)
    ax1.axvline(phases['air_end'], color='orange', linestyle='--', alpha=0.7)

    ax1.set_ylabel('Force (N)')
    ax1.set_title('Forces Acting on Rocket')
    ax1.grid(True, alpha=0.3)
    ax1.legend()
    ax1.set_yscale('log')

    # Acceleration plot
    ax2.plot(flight_data.time, flight_data.acceleration, 'purple', linewidth=2, label='Acceleration')
    add_phase_backgrounds(ax2, phases)

    ax2.axvline(phases['water_end'], color='red', linestyle='--', alpha=0.7)
    ax2.axvline(phases['air_end'], color='orange', linestyle='--', alpha=0.7)
    ax2.axhline(0, color='black', linestyle='-', alpha=0.3)
    ax2.axhline(-9.81, color='gray', linestyle=':', alpha=0.7, label='Gravity')

    ax2.set_xlabel('Time (s)')
    ax2.set_ylabel('Acceleration (m/s²)')
    ax2.set_title('Rocket Acceleration')
    ax2.grid(True, alpha=0.3)
    ax2.legend()

    plt.tight_layout()
    return fig

plot_propellant_and_pressure(flight_data, phases)

Plot propellant masses and pressure.

Source code in waterrocketpy/visualization/plot_flight_data.py

def plot_propellant_and_pressure(flight_data, phases):
    """Plot propellant masses and pressure."""
    fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(12, 8))

    # Propellant masses
    ax1.plot(flight_data.time, flight_data.water_mass * 1000, 'b-', linewidth=2, label='Water mass')
    ax1.plot(flight_data.time, flight_data.air_mass * 1000, 'g-', linewidth=2, label='Air mass')
    ax1.plot(flight_data.time, flight_data.liquid_gas_mass * 1000, 'orange', linewidth=2, label='Liquid gas mass')

    add_phase_backgrounds(ax1, phases)
    ax1.axvline(phases['water_end'], color='red', linestyle='--', alpha=0.7)
    ax1.axvline(phases['air_end'], color='orange', linestyle='--', alpha=0.7)

    ax1.set_ylabel('Mass (g)')
    ax1.set_title('Propellant Masses')
    ax1.grid(True, alpha=0.3)
    ax1.legend()

    # Pressure and temperature
    ax2_temp = ax2.twinx()

    # Pressure (convert to bar for readability)
    pressure_bar = flight_data.pressure / 1e5
    line1 = ax2.plot(flight_data.time, pressure_bar, 'r-', linewidth=2, label='Pressure')
    ax2.axhline(ATMOSPHERIC_PRESSURE / 1e5, color='red', linestyle=':', alpha=0.7, label='Atmospheric')

    # Temperature
    line2 = ax2_temp.plot(flight_data.time, flight_data.air_temperature, 'orange', linewidth=2, label='Temperature')
    ax2_temp.axhline(INITIAL_TEMPERATURE, color='orange', linestyle=':', alpha=0.7, label='Initial temp')

    add_phase_backgrounds(ax2, phases)
    ax2.axvline(phases['water_end'], color='red', linestyle='--', alpha=0.7)
    ax2.axvline(phases['air_end'], color='orange', linestyle='--', alpha=0.7)

    ax2.set_xlabel('Time (s)')
    ax2.set_ylabel('Pressure (bar)', color='r')
    ax2_temp.set_ylabel('Temperature (K)', color='orange')
    ax2.set_title('Pressure and Temperature')
    ax2.grid(True, alpha=0.3)

    # Combine legends
    lines1, labels1 = ax2.get_legend_handles_labels()
    lines2, labels2 = ax2_temp.get_legend_handles_labels()
    ax2.legend(lines1 + lines2, labels1 + labels2, loc='upper right')

    plt.tight_layout()
    return fig

plot_trajectory_and_velocity(flight_data, phases)

Plot altitude and velocity vs time.

Source code in waterrocketpy/visualization/plot_flight_data.py

def plot_trajectory_and_velocity(flight_data, phases):
    """Plot altitude and velocity vs time."""
    fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(12, 8))

    # Altitude plot
    ax1.plot(flight_data.time, flight_data.altitude, 'b-', linewidth=2, label='Altitude')
    add_phase_backgrounds(ax1, phases)

    # Mark key events
    ax1.axvline(phases['water_end'], color='red', linestyle='--', alpha=0.7, label='Water depleted')
    ax1.axvline(phases['air_end'], color='orange', linestyle='--', alpha=0.7, label='Air depleted')
    ax1.axvline(phases['apogee_time'], color='green', linestyle='--', alpha=0.7, label='Apogee')

    ax1.set_ylabel('Altitude (m)')
    ax1.set_title('Rocket Trajectory')
    ax1.grid(True, alpha=0.3)
    ax1.legend()

    # Velocity plot
    ax2.plot(flight_data.time, flight_data.velocity, 'r-', linewidth=2, label='Velocity')
    add_phase_backgrounds(ax2, phases)

    # Mark key events
    ax2.axvline(phases['water_end'], color='red', linestyle='--', alpha=0.7)
    ax2.axvline(phases['air_end'], color='orange', linestyle='--', alpha=0.7)
    ax2.axvline(phases['apogee_time'], color='green', linestyle='--', alpha=0.7)
    ax2.axhline(0, color='black', linestyle='-', alpha=0.3)

    ax2.set_xlabel('Time (s)')
    ax2.set_ylabel('Velocity (m/s)')
    ax2.set_title('Rocket Velocity')
    ax2.grid(True, alpha=0.3)
    ax2.legend()

    plt.tight_layout()
    return fig

print_flight_summary(flight_data, phases)

Print a comprehensive flight summary.

Source code in waterrocketpy/visualization/plot_flight_data.py

def print_flight_summary(flight_data, phases):
    """Print a comprehensive flight summary."""
    print("\n" + "="*60)
    print("WATER ROCKET FLIGHT ANALYSIS SUMMARY")
    print("="*60)

    summary = create_summary_table(flight_data, phases)

    for category, values in summary.items():
        print(f"\n{category}:")
        print("-" * len(category))
        for key, value in values.items():
            print(f"  {key:<25}: {value}")

    print("\n" + "="*60)

setup_plot_style()

Configure matplotlib for professional-looking plots.

Source code in waterrocketpy/visualization/plot_flight_data.py

def setup_plot_style():
    """Configure matplotlib for professional-looking plots."""
    plt.style.use('seaborn-v0_8')
    plt.rcParams.update({
        'figure.figsize': (16, 12),
        'font.size': 10,
        'axes.titlesize': 12,
        'axes.labelsize': 11,
        'xtick.labelsize': 9,
        'ytick.labelsize': 9,
        'legend.fontsize': 9,
        'lines.linewidth': 1.5,
        'grid.alpha': 0.3
    })