v0.2.0 tasks

[wolearyc]

New features

• DOFWarning. This warning is written when a DOF amplitudes do not 'span' 0. This would usually be unintentional.
• ARTModel, a subclass of InterpolationModel that specifically handles atomic Raman tensors
• Masking: Disable certain degrees of freedom in InterpolationModel to calculate partial Raman spectra.
• repr methods for interpolation models to help user keep track of model state
• Workflow for performing calculations necessary to build InterpolationModel's
  • dummy=True option in InterpolationModel to allow dry-run of model and to understand what data is required
  • Utilities for writing displaced structures given directions/displacements and amplitudes, probably built into ReferenceStructure.
• Write support for POSCAR
• Read support for POSCAR

Major changes

• Changed IO package structure to favor file IO via submodules. Submodules are used to specify file formats; generic (though less flexible) IO functions remain available as they are useful in certain cases.
• Favor properties over traditional getter and setters
• Cartesian vs. fractional coordinates
  • Changing variable names: 'fractional_*' -> *
  • Clarifying between fractional and cartesian directions/displacements

Minor enhancements and bugfixes:

• Make shape checking functions more flexible
• More tests
• Refactor and update package/module structure
• StructuralSymmetry --> ReferenceStructure

Documentation updates

• Clarify units, both in some sort of dedicated section and in docstrings
• InterpolationPolarizabilityModel-> InterpolationModel
• Add logo to documentation
• Advanced tutorial to cover masking.
• Dedicated IO guide, with links throughout docstrings.
• Proper links throughout the documentation
• Generally a higher level of polish
• Full guide covering displacement writing and dummy models.