import numpy as np import h5py npart = 2 pos = np.array([[1.0, 1.0, 1.0], [2.0, 1.0, 1.0]]) # pos = np.array([[1.,1.,1.], [1.57735,1.57735,1.57735]]) # diagonals of T are 0 vel = np.array([[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]]) ids = np.arange(1, npart + 1) mass = np.array([1.0] * npart) # File file = h5py.File("test_tensors.hdf5", "w") # Units grp = file.create_group("/Units") grp.attrs["Unit length in cgs (U_L)"] = 3.086e21 grp.attrs["Unit mass in cgs (U_M)"] = 1.988e33 grp.attrs["Unit time in cgs (U_t)"] = 3.086e16 grp.attrs["Unit current in cgs (U_I)"] = 1.0 grp.attrs["Unit temperature in cgs (U_T)"] = 1.0 # Header grp = file.create_group("/Header") grp.attrs["BoxSize"] = 1000.0 grp.attrs["NumPart_Total"] = [0, 0, 0, 0, npart, 0] grp.attrs["NumPart_Total_HighWord"] = [0, 0, 0, 0, 0, 0] grp.attrs["NumPart_ThisFile"] = [0, 0, 0, 0, npart, 0] grp.attrs["Time"] = 0.0 grp.attrs["NumFilesPerSnapshot"] = 1 grp.attrs["MassTable"] = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0] grp.attrs["Flag_Entropy_ICs"] = [0, 0, 0, 0, 0, 0] grp.attrs["Dimension"] = 3 # Particle group grp1 = file.create_group("/PartType4") ds = grp1.create_dataset("Velocities", (npart, 3), "f", data=vel) ds = grp1.create_dataset("Masses", (npart,), "f", data=mass) ds = grp1.create_dataset("ParticleIDs", (npart,), "L", data=ids) ds = grp1.create_dataset("Coordinates", (npart, 3), "d", data=pos) file.close()