Analysis Tools

Analysis Tools

Post-processing simulation output: error analysis, Fourier transforms, and analytic continuation.

Overview

After a simulation completes, raw bin data must be analyzed to extract physical observables with error bars. The workflow depends on whether HDF5 output was enabled.

Analysis Workflow

With HDF5 (recommended)

$ALF_DIR/Analysis/ana_hdf5.out              # analyze all observables
$ALF_DIR/Analysis/ana_hdf5.out Ener_scal    # analyze a specific observable

Results are written to a res/ subdirectory. The input is a single data.h5 file containing all observables.

Without HDF5

$ALF_DIR/Analysis/ana.out *          # analyze all observables
$ALF_DIR/Analysis/ana.out Ener_scal  # analyze a specific observable

ana.out dispatches to the appropriate analysis routine based on the observable name suffix:

Suffix	Analysis	Output
_scal	Scalar covariance (cov_scal)	<name>J (Jackknife mean ± error)
_eq	Equal-time correlations (cov_eq)	<name>JR (real space), <name>JK (k-space)
_tau	Time-displaced correlations (cov_tau)	<name>_kx_ky/g_dat (k-resolved, τ-dependent)

Legacy Script Workflow

For fine-grained control, the individual analysis programs can be called directly. The script Scripts_and_Parameters_files/analysis.sh demonstrates this:

# Scalar observables
for i in *_scal; do $ALF_DIR/Analysis/cov_scal.out < $i; done

# Equal-time observables
for i in *_eq; do ln -sf $i ineq && $ALF_DIR/Analysis/cov_eq.out; done

# Time-displaced observables (particle channel)
for i in Green_tau; do ln -sf $i intau && $ALF_DIR/Analysis/cov_tau.out; done

# Time-displaced observables (particle-hole channel)
for i in SpinZ_tau Den_tau; do ln -sf $i intau && $ALF_DIR/Analysis/cov_tau_ph.out; done

Available Analysis Programs

Program	Input	Purpose
ana.out	Plain-text bin files	All-in-one dispatcher
ana_hdf5.out	data.h5	All-in-one dispatcher (HDF5)
Max_SAC.out	Analyzed τ-dependent data	MaxEnt / Stochastic Analytic Continuation
convert_bins.py	Plain-text bins	Convert plain-text output to HDF5 format

Legacy Programs

The following programs are called internally by ana.out / ana_hdf5.out. They are rarely needed directly.

Program	Input	Purpose
cov_scal.out	*_scal files	Scalar observable Jackknife analysis
cov_eq.out	*_eq files	Equal-time correlation analysis + Fourier transform
cov_tau.out	*_tau files	Time-displaced correlation analysis (particle channel)
cov_tau_ph.out	*_tau files	Time-displaced correlation analysis (particle-hole channel)
cov_mut.out	Mutual information data	Mutual information covariance analysis

Sub-Pages

• HDF5 Output Format — Structure of data.h5
• Bin Conversion — Converting plain-text output to HDF5
• Analytic Continuation — Maximum entropy and stochastic analytic continuation