I have read a Gadget snapshot as follows: ds = yt.load('../GadgetDiskGalaxy/snapshot_200.hdf5') partID = ad[('PartType0', 'ParticleIDs')]
I then defined a sphere around a Type0 particle using the following lines of code: j = 9000 sp = ds.sphere([px[j],py[j],pz[j]],(20.0,'kpc'))
When I issue the following command: print(sp["particle_index"]) I get:
[ 841624. 890649. 841457. 890473. 865599. 865772. 6258099. 5752659. 5752660. 5777940. 6229883. 5803543.] dimensionless
This shows that there are 12 particles inside the sphere.
I checked and found that the following IDs exist in the 'partID' array: 841624. 890649. 841457. 890473. 865599. 865772.
but these IDs (see below) do NOT exist in the 'partID' array: 6258099. 5752659. 5752660. 5777940. 6229883. 5803543 So the IDs of these 6 particles inside the sphere do not exist in the 'partID' array.
How is this possible since 'partID' (as defined above) must contain the IDs of all Type0 particles ?
I would be grateful if someone could help me with this issue. Best regards, Hassan