added functionality to parse and compare to vtu files

cbutil/__init__.py

@@ -6,3 +6,4 @@ from .data_points import DataPoint, data_point_factory
 from .get_job_info import get_url_from_env, get_job_datapoints
 from .gitlab_api import get_git_infos_from_api
 from .update_data import get_updated_data
+from .compare_vtu import compare_vtu_files

cbutil/compare_vtu.py

+import xml.dom.minidom
+import logging
+import numpy as np
+logger = logging.getLogger(__name__)
+
+
+def read_vtu_file(file_name):
+    try:
+        return xml.dom.minidom.parse(file_name)
+    except Exception as e:
+        logger.error(f"Error parsing {file_name}: {str(e)}")
+        raise
+
+
+def extract_data_array(output, name):
+    data_arrays = output.getElementsByTagName("DataArray")
+    data_array = next(
+        (da for da in data_arrays if da.attributes['Name'].value == name), None)
+    if data_array is None:
+        logging.error(f"Data array '{name}' not found in VTU file.")
+        return None
+    floats = [float(n) for n in data_array.firstChild.data.strip().split()]
+    return np.array(floats, dtype=data_array.attributes["type"].value.lower())
+
+
+def calculate_L2_norm(ref, data):
+    return np.linalg.norm(ref - data)
+
+
+def compare_vtu_files(ref_file, result_file, arrays):
+    ref_output = read_vtu_file(ref_file)
+    result_output = read_vtu_file(result_file)
+    differences = {}
+    for array in arrays:
+        ref = extract_data_array(ref_output, array)
+        result = extract_data_array(result_output, array)
+        if ref is not None and result is not None:
+            differences[f'{array}_L2_diff'] = calculate_L2_norm(ref, result)
+    return differences

pyproject.toml

@@ -15,6 +15,7 @@ dependencies = [
     "gitpython",
     "requests",
     "kadi-apy",
+    "numpy",
     "importlib_resources ; python_version<'3.7'",
 ]
 

tests/test_compare_vtu.py

+import os
+import pytest
+import tempfile
+from cbutil.compare_vtu import compare_vtu_files
+
+
+@pytest.fixture
+def setup_test_files():
+    # Create a reference VTU file and a result VTU file for testing
+
+    # Assuming the reference VTU file contains data arrays 'U1', 'U2', and 'U3'
+    # with values [1.0, 2.0, 3.0], [4.0, 5.0, 6.0], and [7.0, 8.0, 9.0], respectively.
+    # The result VTU file contains identical data arrays.
+
+    # Create the reference VTU file
+    with tempfile.TemporaryDirectory() as tmp_dir:
+        ref_file = f"{tmp_dir}/reference_test_file.vtu"
+        result_file = f"{tmp_dir}/result_test_file.vtu"
+        with open(ref_file, "w") as f:
+            f.write('<?xml version="1.0"?>\n<VTKFile type="UnstructuredGrid" version="0.1" byte_order="LittleEndian">\n')
+            f.write('<UnstructuredGrid>\n<PointData>\n')
+            for array_name, values in zip(['U1', 'U2', 'U3'], [[1.0, 2.0, 3.0], [4.0, 5.0, 6.0], [7.0, 8.0, 9.0]]):
+                f.write(f'<DataArray type="Float64" Name="{array_name}" format="ascii">\n')
+                f.write(" ".join(map(str, values)) + "\n")
+                f.write("</DataArray>\n")
+            f.write('</PointData>\n</UnstructuredGrid>\n</VTKFile>\n')
+
+        # Create the result VTU file (identical to the reference)
+        with open(result_file, "w") as f:
+            f.write('<?xml version="1.0"?>\n<VTKFile type="UnstructuredGrid" version="0.1" byte_order="LittleEndian">\n')
+            f.write('<UnstructuredGrid>\n<PointData>\n')
+            for array_name, values in zip(['U1', 'U2', 'U3'], [[1.0, 2.0, 3.0], [4.0, 5.0, 6.0], [7.0, 8.0, 9.0]]):
+                f.write(f'<DataArray type="Float64" Name="{array_name}" format="ascii">\n')
+                f.write(" ".join(map(str, values)) + "\n")
+                f.write("</DataArray>\n")
+            f.write('</PointData>\n</UnstructuredGrid>\n</VTKFile>\n')
+        yield ref_file, result_file
+
+
+def test_valid_comparison(setup_test_files):
+    ref_file, result_file = setup_test_files
+    result = compare_vtu_files(ref_file, result_file, ['U1', 'U2', 'U3'])
+    assert result['U1_L2_diff'] == pytest.approx(0.0)
+    assert result['U2_L2_diff'] == pytest.approx(0.0)
+    assert result['U3_L2_diff'] == pytest.approx(0.0)
+
+
+def test_missing_reference_file():
+    with pytest.raises(FileNotFoundError):
+        compare_vtu_files("non_existent_file.vtu", "other_file.vtu", ["U1"])
+
+
+def test_missing_data_array(setup_test_files):
+    ref_file, result_file = setup_test_files
+    result = compare_vtu_files(ref_file, result_file, ['U1', 'U2', 'U3', 'U4'])
+    assert 'U4_L2_diff' not in result