Added growing mesh case

Author: fsimonis

growing-mesh/precice-config.xml

@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<precice-configuration experimental="True" allow-remeshing="True">
+  <log>
+    <sink
+      filter="%Severity% >= debug and %Rank% = 0"
+      format="---[precice] %ColorizedSeverity% %Message%"
+      enabled="true" />
+  </log>
+
+  <profiling mode="all" />
+
+  <data:scalar name="Data-Left" />
+  <data:scalar name="Data-Right" />
+
+  <mesh name="Left-Mesh" dimensions="3">
+    <use-data name="Data-Left" />
+    <use-data name="Data-Right" />
+  </mesh>
+
+  <mesh name="Right-Mesh" dimensions="3">
+    <use-data name="Data-Left" />
+    <use-data name="Data-Right" />
+  </mesh>
+
+  <participant name="Left">
+    <provide-mesh name="Left-Mesh" />
+    <write-data name="Data-Left" mesh="Left-Mesh" />
+    <read-data name="Data-Right" mesh="Left-Mesh" />
+    <receive-mesh name="Right-Mesh" from="Right" />
+    <mapping:nearest-neighbor
+      direction="read"
+      from="Right-Mesh"
+      to="Left-Mesh"
+      constraint="consistent" />
+  </participant>
+
+  <participant name="Right">
+    <provide-mesh name="Right-Mesh" />
+    <read-data name="Data-Left" mesh="Right-Mesh" />
+    <write-data name="Data-Right" mesh="Right-Mesh" />
+    <receive-mesh name="Left-Mesh" from="Left" />
+    <mapping:nearest-neighbor
+      direction="read"
+      from="Left-Mesh"
+      to="Right-Mesh"
+      constraint="consistent" />
+  </participant>
+
+  <m2n:sockets acceptor="Left" connector="Right" exchange-directory=".." />
+
+  <coupling-scheme:parallel-explicit>
+    <time-window-size value="1" />
+    <max-time-windows value="12" />
+    <participants first="Left" second="Right" />
+    <exchange data="Data-Left" mesh="Left-Mesh" from="Left" to="Right" />
+    <exchange data="Data-Right" mesh="Right-Mesh" from="Right" to="Left" />
+  </coupling-scheme:parallel-explicit>
+</precice-configuration>

growing-mesh/solver/requirements.txt

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+mpi4py
+pyprecice @ git+https://github.com/precice/python-bindings.git@develop

growing-mesh/solver/run_left.sh

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+#!/bin/sh
+set -e -u
+
+python3 -m venv .venvl
+. .venvl/bin/activate
+pip install -r requirements.txt
+
+if [ $# -eq 0 ]; then
+  python3 solver.py Left
+else
+  mpirun -n "$@" python3 solver.py Left
+fi

growing-mesh/solver/run_right.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+set -e -u
+
+python3 -m venv .venvr
+. .venvr/bin/activate
+pip install -r requirements.txt
+
+if [ $# -eq 0 ]; then
+  python3 solver.py Right
+else
+  mpirun -n "$@" python3 solver.py Right
+fi

growing-mesh/solver/solver.py

@@ -0,0 +1,122 @@
+#!/bin/python3
+
+import precice
+import numpy as np
+import math
+import sys
+from mpi4py import MPI
+
+import argparse
+
+parser = argparse.ArgumentParser()
+parser.add_argument("participant", choices=["Left", "Right"])
+parser.add_argument("--config", "-c", default="../precice-config.xml")
+parser.add_argument("--no-remesh", dest="remesh", action="store_false")
+args = parser.parse_args()
+
+participant_name = args.participant
+remote_name = "Left" if participant_name == "Right" else "Right"
+
+# x is partitioned per rank and doesn't change
+nx = 256 * 3
+x = 0.0, 1.0
+ny = 256 * 3
+y = 0.0, 1.0
+
+# y grows over time
+newNodesPerEvent = 2
+eventFrequency = 3  # time windows
+dz = 0.1
+
+
+# Handle partitioning
+world = MPI.COMM_WORLD
+size: int = world.size
+rank: int = world.rank
+
+parts: int = int(math.sqrt(size))
+assert parts**2 == size, "size must be a square value"
+assert math.remainder(nx, parts) == 0, f"{nx=} must be dividable by {parts=}"
+
+# current parition in x, y
+px = rank % parts
+py = rank // parts
+
+# nodes per parition
+nxp = nx // parts
+nyp = ny // parts
+
+# node slide per partition
+nxps = slice(nxp * px, nxp * (px + 1))
+nyps = slice(nyp * py, nyp * (py + 1))
+
+print(f"{rank=} {nxps=} {nyps=}")
+
+
+def requiresEvent(tw):
+    return tw % eventFrequency == 0
+
+
+assert not requiresEvent(eventFrequency - 1)
+assert requiresEvent(eventFrequency)
+assert not requiresEvent(eventFrequency + 1)
+
+
+def eventsAt(tw):
+    # First event block at tw=0, second at eventFrequency
+    return 1 + math.floor(tw / eventFrequency)
+
+
+assert eventsAt(0) == 1
+assert eventsAt(eventFrequency - 1) == 1
+assert eventsAt(eventFrequency) == 2
+assert eventsAt(eventFrequency + 1) == 2
+
+
+def getMeshAtTimeWindow(tw):
+    znodes = eventsAt(tw) * newNodesPerEvent
+
+    xs = np.linspace(x[0], x[1], nx)[nxps]
+    ys = np.linspace(y[0], y[1], ny)[nyps]
+    zs = np.array(range(znodes)) * dz
+
+    return np.reshape([(x, y, z) for z in zs for y in ys for x in xs], (-1, 3))
+
+
+participant = precice.Participant(participant_name, args.config, rank, size)
+
+mesh_name = participant_name + "-Mesh"
+read_data_name = "Data-" + remote_name
+write_data_name = "Data-" + participant_name
+
+coords = getMeshAtTimeWindow(0)
+vertex_ids = participant.set_mesh_vertices(mesh_name, coords)
+participant.initialize()
+
+tw = 1
+while participant.is_coupling_ongoing():
+    dt = participant.get_max_time_step_size()
+
+    data = participant.read_data(mesh_name, read_data_name, vertex_ids, dt)
+    if rank == 0:
+        print(data)
+
+    if args.remesh and requiresEvent(tw):
+        oldCount = len(coords)
+        coords = getMeshAtTimeWindow(tw)
+        if rank == 0:
+            print(
+                f"Event grows local mesh from {oldCount} to {
+                    len(coords)} and global mesh from {
+                    oldCount *
+                    size} to {
+                    len(coords) *
+                    size}")
+        participant.reset_mesh(mesh_name)
+        vertex_ids = participant.set_mesh_vertices(mesh_name, coords)
+
+    data = np.full(len(coords), tw)
+    participant.write_data(mesh_name, write_data_name, vertex_ids, data)
+
+    participant.advance(dt)
+    tw += 1