dirac_to_dirac_approx_short

Single-threaded Dirac-to-Dirac reduction.

Overview

dirac_to_dirac_approx_short<T> reduces a Dirac mixture with M components to a compact mixture with L components in N dimensions.

This is the base (non-threaded) implementation.

It performs gradient-based optimization of the internal distance metric using a GSL minimizer backend.

Use this implementation for:

• Small to medium problem sizes
• Deterministic execution
• Environments where threading is not desired

For a multi-threaded drop-in replacement, see:

• dirac_to_dirac_approx_short_thread

Interface

Inherits:

• dirac_to_dirac_approx_i<T>

Template parameter:

• T ∈ {float, double}

Provides overloads of:

• approximate(...)
• modified_van_mises_distance_sq(...)
• modified_van_mises_distance_sq_derivative(...)

Supported Input Formats

Three overload families are available:

• Raw pointer interface (T*)
• GSL vector interface (gsl_vector / gsl_vector_float)
• GSL matrix interface (gsl_matrix / gsl_matrix_float)

Memory layout and parameter semantics are identical across overloads.

Weights

• wY: weights of the input Dirac mixture
• wX: weights of the reduced Dirac mixture

If nullptr:

• Uniform weights are assumed

Example (Raw Pointer)

dirac_to_dirac_approx_short<double> reducer;
 
bool ok = reducer.approximate(
    y,        // input points (M × N)
    M,
    L,
    N,
    bMax,
    x,        // initial guess / output
    wX,       // reduced weights (optional)
    wY,       // input weights (optional)
    &result,
    options
);

Example (GSL Vector)

dirac_to_dirac_approx_short<double> reducer;
 
bool ok = reducer.approximate(
    yVector,
    L,
    N,
    bMax,
    xVector,
    wXVector,
    wYVector,
    &result,
    options
);

Example (GSL Matrix)

dirac_to_dirac_approx_short<double> reducer;
 
bool ok = reducer.approximate(
    yMatrix,
    L,
    bMax,
    xMatrix,
    wXVector,
    wYVector,
    &result,
    options
);

Notes

• Deterministic single-threaded execution
• Uses analytical gradient evaluation
• Interface-compatible with dirac_to_dirac_approx_short_thread