Module irreg_fdata 

Irregular functional data operations.

This module provides data structures and algorithms for functional data where observations have different evaluation points (irregular/sparse sampling).

Storage Format

Uses a CSR-like (Compressed Sparse Row) format for efficient storage:

• offsets[i]..offsets[i+1] gives the slice indices for observation i
• argvals and values store all data contiguously

This format is memory-efficient and enables parallel processing of observations.

Example

For 3 curves with varying numbers of observation points:

• Curve 0: 5 points
• Curve 1: 3 points
• Curve 2: 7 points

The offsets would be: [0, 5, 8, 15]

Structs

IrregFdata

Compressed storage for irregular functional data.

Functions

cov_irreg

Estimate covariance at a grid of points using local linear smoothing.

integrate_irreg

Compute integral of each curve using trapezoidal rule.

integrate_irreg_struct

Compute integral for IrregFdata struct.

mean_irreg

Estimate mean function at specified target points using kernel smoothing.

metric_lp_irreg

Compute pairwise Lp distances for irregular functional data.

norm_lp_irreg

Compute Lp norm for each curve in irregular functional data.

to_regular_grid

Convert irregular data to regular grid via linear interpolation.