alexlib · April 12, 2025 18:31 · Apr 12, 2025 · Apr 12, 2025
diff --git a/trajectories_to_txt_for_Paraview.py b/trajectories_to_txt_for_Paraview.py
@@ -0,0 +1,45 @@
+import pandas as pd
+from flowtracks.scene import Scene
+import numpy as np
+
+h5_name = r'../corner_51.h5'
+
+particles = Scene(h5_name)
+ids = particles.trajectory_ids()
+
+dataframes = []
+for id in particles.trajectory_ids()[:100]:
+    traj  = particles.trajectory_by_id(id)
+
+# or for traj in particles.iter_trajectories(): if you run for all trajectories
+    dataframes.append(
+        pd.DataFrame.from_records(
+            traj, columns=["x", "y", "z", "dx", "dy", "dz", "frame", "particle"]
+        )
+    )
+
+df = pd.concat(dataframes, ignore_index=True)
+df["particle"] = df["particle"].astype(np.int32)
+df["frame"] = df["frame"].astype(np.int32)
+df.reset_index(inplace=True, drop=True)
+
+
+
+# Paraview does not recognize it as a set without _000001.txt, so we the first 10000
+# ptv_is.10001 is becoming ptv_00001.txt
+
+print(df.head())
+print('-------')
+print(df.tail())
+
+df_grouped = df.reset_index().groupby("frame")
+for index, group in df_grouped:
+    group.to_csv(
+        f"./res/ptv_{int(index):05d}.txt",
+        mode="w",
+        columns=["particle", "x", "y", "z", "dx", "dy", "dz"],
+        index=False,
+    )
+
+print("Saving trajectories to Paraview finished\n")
+
diff --git a/trajectories_to_vtk b/trajectories_to_vtk
@@ -0,0 +1,101 @@
+import pandas as pd
+from flowtracks.scene import Scene
+import numpy as np
+
+h5_name = r'../corner_51.h5'
+
+particles = Scene(h5_name)
+ids = particles.trajectory_ids()
+
+dataframes = []
+for id in particles.trajectory_ids()[:100]:
+    traj  = particles.trajectory_by_id(id)
+
+# or for traj in particles.iter_trajectories(): if you run for all trajectories
+    dataframes.append(
+        pd.DataFrame.from_records(
+            traj, columns=["x", "y", "z", "dx", "dy", "dz", "frame", "particle"]
+        )
+    )
+
+df = pd.concat(dataframes, ignore_index=True)
+df["particle"] = df["particle"].astype(np.int32)
+df["frame"] = df["frame"].astype(np.int32)
+df.reset_index(inplace=True, drop=True)
+
+
+
+# Paraview does not recognize it as a set without _000001.txt, so we the first 10000
+# ptv_is.10001 is becoming ptv_00001.txt
+
+print(df.head())
+print('-------')
+print(df.tail())
+
+df_grouped = df.reset_index().groupby("frame")
+for index, group in df_grouped:
+    group.to_csv(
+        f"./res/ptv_{int(index):05d}.txt",
+        mode="w",
+        columns=["particle", "x", "y", "z", "dx", "dy", "dz"],
+        index=False,
+    )
+
+print("Saving trajectories to Paraview finished\n")
+
+
+import pandas as pd
+import vtk
+from flowtracks.scene import Scene
+import numpy as np
+
+h5_name = r'../corner_51.h5'
+
+particles = Scene(h5_name)
+ids = particles.trajectory_ids()
+
+dataframes = []
+for id in particles.trajectory_ids()[:100]:
+    traj = particles.trajectory_by_id(id)
+    dataframes.append(
+        pd.DataFrame.from_records(
+            traj, columns=["x", "y", "z", "dx", "dy", "dz", "frame", "particle"]
+        )
+    )
+
+df = pd.concat(dataframes, ignore_index=True)
+df["particle"] = df["particle"].astype(np.int32)
+df["frame"] = df["frame"].astype(np.int32)
+df.reset_index(inplace=True, drop=True)
+
+# Group by frame to create separate VTK files for animation
+for frame_num, frame_data in df.groupby('frame'):
+    # Create VTK points and point data
+    points = vtk.vtkPoints()
+    vectors = vtk.vtkFloatArray()
+    vectors.SetNumberOfComponents(3)
+    vectors.SetName("Velocity")
+
+    particle_ids = vtk.vtkIntArray()
+    particle_ids.SetName("ParticleID")
+
+    # Add points and their associated data
+    for _, row in frame_data.iterrows():
+        points.InsertNextPoint(row['x'], row['y'], row['z'])
+        vectors.InsertNextTuple3(row['dx'], row['dy'], row['dz'])
+        particle_ids.InsertNextValue(row['particle'].astype(np.int32))
+
+    # Create polydata
+    polydata = vtk.vtkPolyData()
+    polydata.SetPoints(points)
+    polydata.GetPointData().AddArray(vectors)
+    polydata.GetPointData().AddArray(particle_ids)
+
+    # Write to VTK file
+    writer = vtk.vtkXMLPolyDataWriter()
+    filename = f"./vtk_output/particles_frame_{frame_num:05d}.vtp"
+    writer.SetFileName(filename)
+    writer.SetInputData(polydata)
+    writer.Write()
+
+print("VTK files have been created. Load them in Paraview as a time series.")