qlat.field_type_dict — Field Element-Type Registry

Source: qlat/qlat/field_type_dict.py

Note: Update this document when updating the source file.

Outline

1. Overview

2. Type Dictionaries

   • field_type_dict

   • selected_field_type_dict

   • selected_points_type_dict

3. Element-Type Category Lists

   • field_ctypes_complex

   • field_ctypes_double

   • field_ctypes_float

   • field_ctypes_long

   • field_ctypes_char

4. Internal Lists

5. Examples

---

Overview

field_type_dict provides a centralised registry of field element types used by Qlattice’s field I/O, serialisation, and dispatch machinery. Other modules consult these dictionaries and lists to determine which C++ code path to invoke for a given element type (e.g. ColorMatrix, WilsonVector, ComplexD, RealD, Long, Char).

The three dictionaries are initially empty and are populated at import time by the C/C++ extension modules. The category lists group the ElemType* classes by their numeric representation (complex, double, float, long, char) for convenient lookup.

---

Type Dictionaries

field_type_dict

field_type_dict: dict

Maps Field subclass names (or element-type identifiers) to their corresponding C++ field types. Used by Field constructors and I/O routines to select the correct template instantiation.

selected_field_type_dict

selected_field_type_dict: dict

Maps SelectedField subclass names to their C++ types. Analogous to field_type_dict but for fields that operate on a subset of lattice sites.

selected_points_type_dict

selected_points_type_dict: dict

Maps SelectedPoints subclass names to their C++ types. Used for point-based field data that has been extracted at specific lattice coordinates.

---

Element-Type Category Lists

Each list groups ElemType* classes from qlat_utils by their underlying numeric representation. These are used internally to dispatch to the appropriate C++ template specialisation.

field_ctypes_complex

field_ctypes_complex = [
    ElemTypeColorMatrix,
    ElemTypeWilsonMatrix,
    ElemTypeNonRelWilsonMatrix,
    ElemTypeIsospinMatrix,
    ElemTypeSpinMatrix,
    ElemTypeWilsonVector,
    ElemTypeComplexD,
]

Element types backed by complex-valued (double-precision) data. Includes all spin-color matrix types and scalar complex.

field_ctypes_double

field_ctypes_double = [
    ElemTypeColorMatrix,
    ElemTypeWilsonMatrix,
    ElemTypeNonRelWilsonMatrix,
    ElemTypeIsospinMatrix,
    ElemTypeSpinMatrix,
    ElemTypeWilsonVector,
    ElemTypeComplexD,
    ElemTypeRealD,
]

Element types stored as double-precision real numbers. Superset of field_ctypes_complex plus ElemTypeRealD.

field_ctypes_float

field_ctypes_float = [
    ElemTypeComplexF,
    ElemTypeRealF,
]

Single-precision element types.

field_ctypes_long

field_ctypes_long = [
    ElemTypeLong,
    ElemTypeInt64t,
]

Integer (64-bit) element types.

field_ctypes_char

field_ctypes_char = [
    ElemTypeChar,
    ElemTypeInt8t,
]

Byte-level element types.

Note: field_ctypes_char is defined in qlat.field_type_dict but is not re-exported at the top qlat level (not in c.__all__). Access it as qlat.field_type_dict.field_ctypes_char or via import qlat.field_type_dict as ftd; ftd.field_ctypes_char.

---

Internal Lists

These are not exported in __all__ but are available within the module:

Name	Contents
field_ctypes_complex_f	[ElemTypeComplexF]
field_ctypes_complex_or_complex_f	Union of complex and single-precision complex
field_ctypes_double_or_float	Union of double and float categories

---

Examples

Inspecting the Type Dictionaries

import qlat as q
import qlat.field_type_dict as ftd

size_node_list = [
    [1, 1, 1, 1],
]

q.begin_with_mpi(size_node_list)

print("field_type_dict keys:")
for key in sorted(ftd.field_type_dict.keys(), key=str):
    print(f"  {key}")

print("\nselected_field_type_dict keys:")
for key in sorted(ftd.selected_field_type_dict.keys(), key=str):
    print(f"  {key}")

print("\nselected_points_type_dict keys:")
for key in sorted(ftd.selected_points_type_dict.keys(), key=str):
    print(f"  {key}")

q.end_with_mpi()

Checking Element-Type Categories

import qlat as q
import qlat.field_type_dict as ftd

size_node_list = [
    [1, 1, 1, 1],
]

q.begin_with_mpi(size_node_list)

print("Complex element types:")
for et in q.field_ctypes_complex:
    print(f"  {et}")

print("\nDouble element types:")
for et in q.field_ctypes_double:
    print(f"  {et}")

print("\nFloat element types:")
for et in q.field_ctypes_float:
    print(f"  {et}")

print("\nLong element types:")
for et in q.field_ctypes_long:
    print(f"  {et}")

print("\nChar element types:")
for et in ftd.field_ctypes_char:
    print(f"  {et}")

q.end_with_mpi()

Using Type Lists for Dispatch

import qlat as q

size_node_list = [
    [1, 1, 1, 1],
]

q.begin_with_mpi(size_node_list)

def is_complex_type(elem_type):
    return elem_type in q.field_ctypes_complex

def is_double_type(elem_type):
    return elem_type in q.field_ctypes_double

for et in q.field_ctypes_double:
    print(f"{et}: complex={is_complex_type(et)}, double={is_double_type(et)}")

q.end_with_mpi()