Tutorial: Comparing Trajectory Analysis Methods

This tutorial demonstrates how to use the BinningTrajectoryAnalyzer and SlicedTrajectoryAnalyzer classes to analyze and compare contact angle and surface area data from trajectory simulations.

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Introduction

The BinningTrajectoryAnalyzer and SlicedTrajectoryAnalyzer classes are designed to analyze trajectory data, specifically focusing on surface area and contact angle statistics. These tools are useful for comparing different analysis methods and visualizing results.

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Setup and Initialization

Import the Classes

Ensure you have the required classes imported:

from wetting_angle_kit.visualization_angles.binning_analyzer import (
    BinningTrajectoryAnalyzer,
)
from wetting_angle_kit.visualization_angles.sliced_analyzer import (
    SlicedTrajectoryAnalyzer,
)
from wetting_angle_kit.visualization_angles.comparison_methods import (
    MethodComparison,
)

Initialize the Analyzers

Specify the directories containing your trajectory data:

directories = [
    "sliced_analysis_CA/result_dump_traj_2k_reduce_binned",
    "sliced_analysis_CA/result_dump_traj_500_reduce_binned",
    "sliced_analysis_CA/result_dump_traj_1k_reduce_binned",
    "sliced_analysis_CA/result_dump_traj_8k_reduce_binned",
]

# Initialize the analyzers
sliced = SlicedTrajectoryAnalyzer(directories)
binning = BinningTrajectoryAnalyzer(directories)

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Running the Analysis

Analyze Data

Run the analysis for both methods:

sliced.analyze()
binning.analyze()

Example Output

Directory: sliced_analysis_CA/result_dump_traj_2k_reduce_binned
  Method: Sliced Analysis
  Mean Surface Area: 2770.0659
  Mean Contact Angle: 91.7015°

Directory: binning_analysis_CA/result_dump_traj_2k_reduce_binned
  Method: Binning Analysis
  Mean Surface Area: 2748.5427
  Mean Contact Angle: 91.9236°

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Interpreting the Output

• Mean Surface Area: The average surface area for each trajectory.

• Mean Contact Angle: The average contact angle for each trajectory.

• Standard Deviation: Indicates the variability of the data.

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Visualisation

Plot Mean Angle vs Surface Area

sliced.plot_mean_angle_vs_surface(save_path="mean_angle_vs_surface_sliced.png")
binning.plot_mean_angle_vs_surface(save_path="mean_angle_vs_surface_binning.png")

Plot Median Angle Evolution

For the sliced method, plot the evolution of median angles:

sliced.plot_median_alfas_evolution(save_path="evolution_of_angles_sliced_method.png")

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Method Comparison

Compare Statistics

Use the MethodComparison class to compare the two methods:

comparison = MethodComparison([sliced, binning])
comparison.plot_side_by_side_comparison(save_path="comparison.png")
comparison.compare_statistics()

Example Output

======================================================================
METHOD COMPARISON STATISTICS
======================================================================
Sliced Analysis:
----------------------------------------------------------------------
  sliced_analysis_CA/traj_2k/:
    Mean Surface Area: 2770.0659 ± 15.2001
    Mean Angle: 91.7015° ± 5.6130°
  Overall Statistics:
    Total samples: 196
    Mean Surface Area: 4001.0215
    Mean Angle: 91.8326°
    Std Angle: 6.2027°

Binning Analysis:
----------------------------------------------------------------------
  binning_analysis_CA/traj_2k:
    Mean Surface Area: 2748.5427 ± 0.0000
    Mean Angle: 91.9236° ± 0.0000°
  Overall Statistics:
    Total samples: 4
    Mean Surface Area: 4022.1019
    Mean Angle: 92.0876°
    Std Angle: 0.2391°

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Conclusion

• The SlicedTrajectoryAnalyzer provides more detailed statistics with higher sample counts.

• The BinningTrajectoryAnalyzer offers a simplified, binning approach.

• Use the comparison tools to visualize and interpret differences between methods.

Additional Notes

• Ensure your data directories are correctly formatted and contain the required log files.