Data Querying & Analysis¶
Cute Plot provides powerful data querying and statistical analysis tools that enable in-depth exploration of time-series data through interactive selection and comprehensive calculations.
Query Rectangle System¶
Creating Query Rectangles¶
The primary tool for data analysis is the query rectangle:
- Ctrl+Click: Hold Ctrl and click in any subplot
- Drag to define region: Drag to create rectangular selection
- Analysis activation: Release to perform analysis on selected region
- Visual feedback: Green rectangle shows selected region
Query Rectangle Features¶
- Precise selection: Pixel-accurate region selection
- Visual feedback: Semi-transparent green overlay
- Adjustable boundaries: Resize rectangle after creation
- Multiple series: Analyzes all series within selection region
Interactive Adjustment¶
After creation, query rectangles can be modified: - Corner handles: Drag corners to resize - Edge handles: Drag edges to resize in one dimension - Move entire rectangle: Drag interior to move without resizing
Statistical Analysis¶
Basic Statistics¶
Automatically calculated for all series in query region:
Central Tendencies¶
- Mean: Average value in selected region
- Median: Middle value when data sorted
- Mode: Most frequently occurring value (if applicable)
Variability Measures¶
- Standard Deviation: Measure of data spread
- Variance: Square of standard deviation
- Range: Difference between max and min values
- Min/Max: Minimum and maximum values in region
Data Characteristics¶
- Count: Number of data points in region
- Window Width: Time span of selected region
- Sample Rate: Derived from time intervals
Advanced Calculations¶
Configurable through Settings → Query Options:
Signal Analysis¶
- RMS (Root Mean Square): Effective value of signal
- Frequency Analysis: Dominant frequencies in selection
- Ramp Rate: Rate of change analysis
- Peak Detection: Local maxima and minima
Dynamic Response Analysis¶
- Rise Time: Time to reach specified percentage of final value
- Settling Time: Time to settle within tolerance band
- Recovery Time: Time to return to baseline after disturbance
- Overshoot: Maximum deviation beyond final value
Power Systems Analysis¶
- Damping Ratio: Oscillation damping characteristics
- Frequency Response: System frequency characteristics
- THD (Total Harmonic Distortion): Harmonic content analysis
Advanced Signal Processing¶
- FFT Analysis: Frequency domain analysis
- Correlation Analysis: Cross-correlation between signals
- Spectral Density: Power spectral density estimation
Query Display Modes¶
Drag Annotation (Real-time)¶
During rectangle creation, basic statistics shown in real-time:
Region: (1.25s, 0.95) to (2.45s, 1.15)
Width: 1.20s | Series: 3 selected
Min: 0.945 Max: 1.143 Mean: 1.024
Detailed Analysis Tooltip¶
After rectangle creation, comprehensive analysis displayed: - Statistical summary: All enabled statistics - Per-series breakdown: Individual analysis for each series - Comparative metrics: Cross-series comparisons - Frequency analysis: FFT results (if enabled)
Configuration Options¶
Query Settings¶
Access via Settings → Query Options to enable/disable:
Basic Statistics (Always Available)¶
- Min, Max, Mean, Standard Deviation, Count
Advanced Options (Configurable)¶
- Window Width: Time span analysis
- Frequency: Dominant frequency detection
- Ramp Rate: Rate of change calculations
- RMS: Root mean square values
- Rise Time: Dynamic response analysis
- Recovery Time: Return-to-baseline analysis
- Settling Time: Stability analysis
- Damping Ratio: Oscillation characteristics
- FFT Analysis: Frequency domain analysis
Performance Considerations¶
- Selective enabling: Enable only needed calculations for better performance
- Large datasets: Advanced calculations may take time on large selections
- Real-time updates: Basic statistics update in real-time during selection
Multi-Series Analysis¶
Cross-Series Statistics¶
When multiple series are in the query region: - Individual analysis: Each series analyzed separately - Comparative metrics: Cross-series comparisons - Correlation analysis: Relationship between series - Synchronization: Time-aligned analysis
Series Identification¶
- Color coding: Series identified by plot line colors
- Name display: Series names shown in analysis results
- Value ranges: Individual min/max for each series
Advanced Analysis Features¶
FFT Analysis¶
When FFT Analysis is enabled:
Frequency Domain Results¶
- Dominant frequencies: Peak frequencies in selection
- Magnitude spectrum: Frequency component strengths
- Phase information: Phase relationships (if applicable)
- Harmonic analysis: Harmonic content identification
Power Systems Applications¶
- Power quality: Harmonic distortion analysis
- Oscillation modes: System oscillation frequencies
- Resonance detection: Natural frequency identification
Dynamic Response Analysis¶
Specialized for control systems and power systems:
Rise Time Analysis¶
- 10-90% rise time: Standard control system metric
- Custom thresholds: Configurable percentage thresholds
- Multiple measurements: Different rise time definitions
Settling Time Analysis¶
- Tolerance bands: Configurable settling criteria
- Final value detection: Automatic final value determination
- Stability assessment: Long-term stability evaluation
Query Rectangle Management¶
Multiple Query Rectangles¶
- One per plot: Each subplot can have one active query rectangle
- Independent analysis: Each rectangle analyzes independently
- Comparison capability: Compare analysis results across subplots
Cleanup and Management¶
- Auto-replacement: New query rectangle replaces previous one
- Manual deletion: Right-click to delete query rectangle
- Session persistence: Query rectangles maintained during session
Integration with Other Features¶
Templates¶
- Query-friendly layouts: Templates can optimize layouts for analysis
- Consistent regions: Apply similar analysis regions across files
- Automated workflows: Combine templates with query analysis
Annotations¶
- Reference markers: Use annotations to mark analysis regions
- Result highlighting: Annotate significant findings
- Documentation: Document analysis results with text annotations
Screenshots¶
- Analysis capture: Screenshots include query rectangles and results
- Documentation: Perfect for reports and presentations
- Result preservation: Capture analysis state for later reference
Use Cases and Applications¶
Power System Analysis¶
Fault Analysis:
- Pre-fault conditions (steady state)
- During-fault behavior (transient response)
- Post-fault recovery (return to steady state)
Stability Studies:
- Oscillation frequency analysis
- Damping ratio calculation
- Recovery time assessment
Control System Analysis¶
Step Response:
- Rise time measurement
- Overshoot calculation
- Settling time determination
Frequency Response:
- Bandwidth determination
- Resonance identification
- Stability margins
Signal Processing¶
Time-Domain Analysis:
- Statistical characterization
- Trend analysis
- Anomaly detection
Frequency-Domain Analysis:
- Spectral content
- Harmonic analysis
- Noise characterization
Best Practices¶
Effective Query Selection¶
- Representative regions: Select regions that represent phenomena of interest
- Avoid transitions: Be careful with transient regions
- Multiple perspectives: Use multiple query regions for comprehensive analysis
Analysis Configuration¶
- Enable needed features: Only enable calculations you need
- Performance balance: Consider computation time vs. completeness
- Consistent settings: Use consistent settings across similar analyses
Result Interpretation¶
- Context awareness: Consider the physical meaning of statistical results
- Cross-validation: Verify results with multiple analysis approaches
- Documentation: Document significant findings and methodologies
Troubleshooting¶
Common Query Issues¶
Query Rectangle Not Appearing¶
- Ctrl key: Ensure Ctrl is held during click
- Plot area: Click within subplot boundaries
- Series presence: Ensure subplot contains data series
Analysis Not Updating¶
- Rectangle completion: Ensure rectangle creation is completed
- Settings check: Verify desired calculations are enabled
- Data validity: Confirm selected region contains valid data
Performance Issues¶
- Disable unused calculations: Turn off unneeded analysis options
- Smaller regions: Select smaller analysis regions
- Fewer series: Limit number of series in analysis region
Calculation Issues¶
- Invalid data: Check for NaN or infinite values in selection
- Insufficient data: Ensure adequate data points for analysis
- Time alignment: Verify time synchronization for multi-series analysis
Next Steps¶
Master data querying and analysis, then explore: 1. Data Transformations 2. Advanced Configuration 3. Developer Guide
Analysis tip: Start with basic statistics to understand your data, then enable advanced features as needed for deeper insights