Welcome to the PyXRD docs!

PyXRD is a python implementation of the matrix algorithm for computer modeling of X-ray diffraction (XRD) patterns of disordered lamellar structures. It’s goals are to:

1. provide an easy user-interface for end-users
2. provide basic tools for displaying and manipulating XRD patterns
3. produce high-quality (publication-grade) figures
4. make modelling of XRD patterns for mixed-layer clay minerals ‘easy’
5. be free and open-source

Motivation

PyXRD was written with the multi-specimen full-profile fitting method in mind. The direct result of this is the ability to ‘share’ parameters among similar phases.

This allows for instance to have an air-dry and a glycolated illite-smectite share their coherent scattering domain size, but still have different basal spacings and interlayer compositions for the smectite component.

Other features are (incomplete list):

• Import/export several common XRD formats (.RD, .RAW, .CPI, ASCII)
• simple background subtraction/addition (linear or custom patterns)
• smoothing patterns and adding noise to patterns
• peak finding and annotating (markers)
• custom line colors, line widths, pattern positions, …
• goniometer settings (wavelengths, geometry settings, …)
• specimen settings (sample length, absorption, …)

• automatic parameter refinement using several algorithms, e.g.:

  • L BFGS B
  • Brute Force
  • Covariation Matrix Adapation Evolutionary Strategy (CMA-ES; using DEAP)
  • Multiple Particle Swarm Optimization (MPSO; using DEAP)
  • scripting support

Contents

• Library API Reference
  • Atoms module
  • Probabilities module
  • Phases module
  • Goniometer module
  • Mixture module
  • Project module
  • Calculations
• Script Tutorial
  • Introduction
  • Hello World script
  • Running the script

Indices and tables

• Index
• Module Index
• Search Page