Parallel computing

This is a rather low science day.

I spent most of today understanding the mpi4py library.
To launch MC calculation on a multiple-threads machine, I would like to first scatter the indices for MC iteration to each thread.

With mpi4py this is what I do:

###### load necessary libraries #############
from mpi4py import MPI
from numpy import *

c = MPI.COMM_WORLD
### prepare to assign obsids to each node
nloop = 8
allloop = range(nloop)
crank = c.Get_rank()
csize = c.Get_size()

### ------------------------------------------------
### this chunk scatters [allloop] to each thread as [loop]
loop = []
for i in range(len(allloop)):
if mod(allloop[i], csize) == crank:
loop.append(allloop[i])
### ------------------------------------------------

### MC_calcul.py uses elements in the loop to decide
### which MC calculation it should execute.
execfile('MC_calcul.py')

AKARI data and Carina

After a long break of winter sickness, vacation, and JWST workshop, I finally start this blog officially.

For our EMPIRE project, I am still at the book-keeping stage.
Many relevant observations are still missing in our current catalog.
I am planning to pull together all the available IRC/NIR/slit observations on these galaxies we currently include in the catalog.
This will take some time.
The AKARI IRC is designed to be a rather efficient instrument to carry out imaging and spectroscopy observations simultaneously.
Other than the slit-less spectroscopic observations, IRC is also equipped with slits to block out the adjacent sources.
In our catalog, we use only slit observations to reduce the complexity of calibration.

I also come back to the Carina MeudonPDR fitting.
For the 13CO, I can accept that the Av>40 may not be necessary that the CO further in the depth should all be locked to the ice-phase.
However, the earlier strategy of fixing Av=10 and fit over the entire map is also not ideal for some patch of our map.
I experiment today to first run a full fitting with all four parameters (Omega, P, chi, Av) on only 12CO.
Based on the Av values and the discrepancy between the model-predicted and observed 13CO, I will then decide whether Av should be locked to 10 on a given pixel.
The results should be ready tomorrow.