Interactive Frequency Domain Analysis

Explore advanced spectral techniques applied to biological systems. This platform demonstrates key concepts from the comprehensive review on Frequency Domain Analysis in Systems Biology.

Learning Objectives

Master spectral decomposition, wavelet analysis, higher-order statistics, and their applications to biological time series, networks, and omics data.

📊 Power Spectral Density & Phase Coherence

The foundation of frequency domain analysis is the Power Spectral Density (PSD), which quantifies how power is distributed across different frequencies. Phase coherence measures the reliability of oscillatory components in stochastic biological systems.

Signal Generation

Analysis Parameters

Time Domain Signal

Power Spectral Density

Phase Coherence Analysis

Dominant Frequency: 1.00 Hz
Phase Coherence: 0.95
Signal-to-Noise Ratio: 15.2 dB

🌊 Wavelet Analysis for Non-Stationary Signals

Unlike Fourier analysis which assumes stationarity, wavelet transforms can localize spectral features in both time and frequency domains, making them ideal for analyzing transient biological phenomena like damping rhythms or burst events.

Signal Parameters

Analysis Controls

Scales: 50

Time Domain Signal

Time-Frequency Spectrogram

Wavelet Analysis Results

Peak Frequency: 2.5 Hz
Time of Occurrence: 1.2 s
Frequency Spread: ±0.8 Hz
Energy Concentration: 78%

🔗 Higher-Order Spectral Analysis (HOSA)

Higher-Order Spectral Analysis goes beyond the Power Spectral Density to detect quadratic phase coupling (QPC) between frequencies. The bispectrum and bicoherence reveal nonlinear interactions that standard Fourier analysis cannot detect.

Coupled Signal Generation

Analysis Method

Time Domain Signals

Frequency Domain (PSD)

Bispectrum Magnitude

Bicoherence

HOSA Analysis Results

QPC Detected: Yes
Bicoherence Peak: 0.85
Coupling Frequency: 25 Hz
Phase Coupling: 42°

🕸️ Spectral Graph Theory in GRNs

Spectral Graph Theory analyzes gene regulatory networks using eigenvalue decomposition of adjacency and Laplacian matrices. This reveals network connectivity patterns, prioritizes critical interactions, and provides robust analysis against molecular noise.

Network Generation

Spectral Analysis

Network Visualization

Eigenvalue Spectrum

Adjacency Matrix

Network Metrics

Clustering Coefficient: 0.00
Average Path Length: 0.00
Spectral Gap: 0.00
Algebraic Connectivity: 0.00
Network Diameter: 0
Robustness Score: 0.00

🧬 Protein Folding Dynamics

Protein folding is a complex process where linear amino acid sequences self-organize into functional 3D structures. Spectral analysis reveals the dynamical landscape of folding pathways, energy barriers, and conformational transitions that govern protein function and misfolding diseases.

Folding Parameters

Energy Landscape

Folding Trajectory

Conformational Dynamics

Spectral Analysis

Folding Dynamics Metrics

Folding Time: 0.0 ns
Free Energy Barrier: 0.0 kJ/mol
Conformational Entropy: 0.0 kJ/mol·K
Stability Index: 0.0
Transition States: 0
Native Contacts: 0%
RMS Fluctuation: 0.0 Å
Folding Cooperativity: 0.0

⏰ Circadian Rhythm Analysis

Circadian rhythms are biological oscillations with periods of approximately 24 hours. This interactive tool demonstrates spectral analysis of circadian signals, including period detection, phase coherence, and damping rhythm analysis using concepts from specialized tools like Rhythmidia.

Circadian Signal Parameters

Analysis Method

Time Domain Signal

Periodogram Analysis

Phase Distribution

Rhythm Metrics

Detected Period: 24.0 h
Phase Coherence: 0.85
Amplitude Stability: 78%
Rhythm Strength: 0.92

🧬 DNA Transcription Dynamics

DNA transcription involves the conversion of genetic information from DNA to RNA by RNA polymerase. Spectral analysis reveals the dynamical processes of initiation, elongation, pausing, and termination that regulate gene expression and cellular function.

Transcription Parameters

Transcription Kinetics

Gene Expression Profile

RNA Polymerase Movement

Transcriptional Noise

Promoter Occupancy

Spectral Analysis

Transcription Dynamics Metrics

Initiation Rate: 0.0 s⁻¹
Elongation Speed: 0.0 nt/s
Transcription Burst Size: 0.0
Burst Frequency: 0.0 Hz
Pausing Frequency: 0.0
Termination Efficiency: 0%
Expression Noise: 0.0
Regulatory Strength: 0.0