Add CLI command to plot elliptic solver convergence

src/Visualization/Python/CMakeLists.txt

@@ -13,6 +13,7 @@ spectre_python_add_module(
   Plot.py
   PlotAlongLine.py
   PlotDatFile.py
+  PlotEllipticConvergence.py
   PlotMemoryMonitors.py
   PlotPowerMonitors.py
   PlotSizeControl.py

src/Visualization/Python/PlotEllipticConvergence.py

@@ -0,0 +1,137 @@
+#!/usr/bin/env python
+
+# Distributed under the MIT License.
+# See LICENSE.txt for details.
+
+import logging
+from typing import List
+
+import click
+import h5py
+import matplotlib.pyplot as plt
+import numpy as np
+import pandas as pd
+from matplotlib.ticker import MaxNLocator
+
+from spectre.Visualization.Plot import (
+    apply_stylesheet_command,
+    show_or_save_plot_command,
+)
+from spectre.Visualization.ReadH5 import to_dataframe
+
+logger = logging.getLogger(__name__)
+
+
+def split_iteration_sequence(data: pd.DataFrame) -> List[pd.DataFrame]:
+    """Split a dataframe where its index is not strictly increasing.
+
+    Returns a list of dataframes, where each has a strictly increasing index.
+    """
+    split_indices = np.split(
+        np.arange(len(data)), np.nonzero(np.diff(data.index) < 1)[0] + 1
+    )
+    return [data.iloc[split_index] for split_index in split_indices]
+
+
+def plot_elliptic_convergence(
+    h5_file,
+    ax=None,
+    linear_residuals_subfile_name="GmresResiduals.dat",
+    nonlinear_residuals_subfile_name="NewtonRaphsonResiduals.dat",
+):
+    """Plot elliptic solver convergence
+
+    Arguments:
+      h5_file: The H5 reductions file.
+      ax: Optional. The matplotlib axis to plot on.
+      linear_residuals_subfile_name: The name of the subfile containing the
+        linear solver residuals.
+      nonlinear_residuals_subfile_name: The name of the subfile containing the
+        nonlinear solver residuals.
+    """
+    with h5py.File(h5_file, "r") as open_h5file:
+        linear_residuals = split_iteration_sequence(
+            to_dataframe(open_h5file[linear_residuals_subfile_name]).set_index(
+                "Iteration"
+            )
+        )
+        nonlinear_residuals = (
+            split_iteration_sequence(
+                to_dataframe(
+                    open_h5file[nonlinear_residuals_subfile_name]
+                ).set_index("Iteration")
+            )
+            if nonlinear_residuals_subfile_name in open_h5file
+            else None
+        )
+    cumulative_linsolv_iterations = [0] + list(
+        np.cumsum([len(l) - 1 for l in linear_residuals])
+    )
+    norm = (
+        nonlinear_residuals
+        if nonlinear_residuals is not None
+        else linear_residuals
+    )[0]["Residual"].iloc[0]
+    # Plot nonlinear solver residuals
+    if ax is not None:
+        plt.sca(ax)
+    if nonlinear_residuals is not None:
+        m = 0
+        for i, residuals in enumerate(nonlinear_residuals):
+            plt.plot(
+                cumulative_linsolv_iterations[m : m + len(residuals)],
+                residuals["Residual"] / norm,
+                color="black",
+                ls="dotted",
+                marker=".",
+                label="Nonlinear residual" if i == 0 else None,
+            )
+            m += len(residuals) - 1
+    # Plot linear solver residuals
+    for i, residuals in enumerate(linear_residuals):
+        plt.plot(
+            residuals.index + cumulative_linsolv_iterations[i],
+            residuals["Residual"] / norm,
+            color="black",
+            label="Linear residual" if i == 0 else None,
+            marker="." if len(residuals) < 20 else None,
+        )
+
+    # Configure the axes
+    plt.yscale("log")
+    plt.grid()
+    plt.legend()
+    plt.xlabel("Cumulative linear solver iteration")
+    plt.ylabel("Relative residual")
+    plt.title("Elliptic solver convergence")
+    # Allow only integer ticks for the x-axis
+    plt.gca().xaxis.set_major_locator(MaxNLocator(integer=True))
+
+
+@click.command(name="elliptic-convergence")
+@click.argument(
+    "h5_file",
+    type=click.Path(exists=True, file_okay=True, dir_okay=False, readable=True),
+)
+@click.option(
+    "--linear-residuals-subfile-name",
+    help="The name of the subfile containing the linear solver residuals",
+    default="GmresResiduals.dat",
+    show_default=True,
+)
+@click.option(
+    "--nonlinear-residuals-subfile-name",
+    help="The name of the subfile containing the nonlinear solver residuals",
+    default="NewtonRaphsonResiduals.dat",
+    show_default=True,
+)
+@apply_stylesheet_command()
+@show_or_save_plot_command()
+def plot_elliptic_convergence_command(**kwargs):
+    """Plot elliptic solver convergence"""
+    _rich_traceback_guard = True  # Hide traceback until here
+    plot_elliptic_convergence(**kwargs)
+
+
+if __name__ == "__main__":
+    plot_elliptic_convergence_command(help_option_names=["-h", "--help"])

src/Visualization/Python/__init__.py

@@ -9,6 +9,7 @@ def list_commands(self, ctx):
         return [
             "along-line",
             "dat",
+            "elliptic-convergence",
             "memory-monitors",
             "power-monitors",
             "size-control",
@@ -26,6 +27,12 @@ def get_command(self, ctx, name):
             from spectre.Visualization.PlotDatFile import plot_dat_command
 
             return plot_dat_command
+        elif name == "elliptic-convergence":
+            from spectre.Visualization.PlotEllipticConvergence import (
+                plot_elliptic_convergence_command,
+            )
+
+            return plot_elliptic_convergence_command
         elif name == "memory-monitors":
             from spectre.Visualization.PlotMemoryMonitors import (
                 plot_memory_monitors_command,

tests/Unit/Visualization/Python/CMakeLists.txt

@@ -19,6 +19,12 @@ spectre_add_python_bindings_test(
   "unit;visualization;python"
   None)
 
+spectre_add_python_bindings_test(
+  "Unit.Visualization.Python.PlotEllipticConvergence"
+  Test_PlotEllipticConvergence.py
+  "unit;visualization;python"
+  None)
+
 spectre_add_python_bindings_test(
   "Unit.Visualization.Python.PlotMemoryMonitors"
   Test_PlotMemoryMonitors.py
@@ -56,6 +62,11 @@ if(${BUILD_PYTHON_BINDINGS})
     PROPERTIES
     TIMEOUT 10
     )
+  set_tests_properties(
+    "Unit.Visualization.Python.PlotEllipticConvergence"
+    PROPERTIES
+    TIMEOUT 10
+    )
   set_tests_properties(
     "Unit.Visualization.Python.PlotMemoryMonitors"
     PROPERTIES

tests/Unit/Visualization/Python/Test_PlotEllipticConvergence.py

@@ -0,0 +1,70 @@
+# Distributed under the MIT License.
+# See LICENSE.txt for details.
+
+import os
+import shutil
+import unittest
+
+import click
+import numpy as np
+from click.testing import CliRunner
+
+import spectre.Informer as spectre_informer
+import spectre.IO.H5 as spectre_h5
+from spectre.Visualization.PlotEllipticConvergence import (
+    plot_elliptic_convergence_command,
+)
+
+
+class TestPlotEllipticConvergence(unittest.TestCase):
+    def setUp(self):
+        self.test_dir = os.path.join(
+            spectre_informer.unit_test_build_path(),
+            "Visualization/PlotEllipticConvergence",
+        )
+        shutil.rmtree(self.test_dir, ignore_errors=True)
+        self.h5_filename = os.path.join(self.test_dir, "Residuals.h5")
+        os.makedirs(self.test_dir, exist_ok=True)
+        with spectre_h5.H5File(self.h5_filename, "w") as h5_file:
+            linear_residuals = h5_file.insert_dat(
+                "/GmresResiduals",
+                legend=["Iteration", "Residual"],
+                version=0,
+            )
+            linear_residuals.append([0, 1.0])
+            linear_residuals.append([1, 0.5])
+            linear_residuals.append([0, 0.6])
+            linear_residuals.append([1, 0.4])
+            linear_residuals.append([2, 0.2])
+            h5_file.close_current_object()
+            nonlinear_residuals = h5_file.insert_dat(
+                "/NewtonRaphsonResiduals",
+                legend=["Iteration", "Residual"],
+                version=0,
+            )
+            nonlinear_residuals.append([0, 1.0])
+            nonlinear_residuals.append([1, 0.5])
+
+    def tearDown(self):
+        shutil.rmtree(self.test_dir)
+
+    def test_cli(self):
+        output_filename = os.path.join(self.test_dir, "output.pdf")
+        runner = CliRunner()
+        result = runner.invoke(
+            plot_elliptic_convergence_command,
+            [
+                self.h5_filename,
+                "-o",
+                output_filename,
+            ],
+            catch_exceptions=False,
+        )
+        self.assertEqual(result.exit_code, 0)
+        # We can't test that the plot is correct, so just make sure it at least
+        # gets written out.
+        self.assertTrue(os.path.exists(output_filename))
+
+
+if __name__ == "__main__":
+    unittest.main(verbosity=2)