Download Application Programming Interface (API) for the HITRANonline web

Working with HITRAN database using HAPI:
HITRAN Application Programming Interface
Roman V. Kochanova,c, Christian Hilla,b, Piotr Wcisloa,d,
Jonas S. Wilzewskie, Iouli E. Gordona, and Laurence S. Rothmana
aHarvard-Smithsonian
Center for Astrophysics, Cambridge MA, USA
bUniversity
cTomsk
dNicolas
eHarvard
College London, London, UK
State University, Tomsk, RUSSIA
Copernicus University, Torun, POLAND
University, Astronomy Dept, Cambridge MA, USA
Introduction
●
What is API?
●
API, an abbreviation of Application Programming Interface,
is a set of routines, protocols, and tools for building software
applications. The API specifies how software components
should interact and be used in a program code.
– A good API makes it easier to develop a program by
providing all the building blocks. A programmer then puts the
blocks together.
What is HITRAN API (HAPI)?
–
–
–
–
Python module (library of functions) to work with HITRAN
data
Main purpose: extending user's code by the data of HITRAN
and functionality of HITRANonline
Offline part of HITRANonline functionality
Why is API a powerful tool for creating
radiative-transfer codes?
●
Seamless data format conversion
Parsing data (cross-sections, line-by-line, parameters)
“in a background”
–
●
Flexibility
–
–
–
●
●
Large number of input parameters to control calculation
Possibility to add custom user code
Possibility to use different line parameters and compare
results
Portability
Access to external libraries
–
Python, Fortran, C++ ...
What is HAPI for?
●
●
●
●
Retrieve and use of HITRANonline data (line lists, cross
sections, molecule and isotopologue info...) from a
program written in Python (HITRANonline data is parsed
automatically)
Reduce the load of HITRANonline web service
(calculation of cross sections can be resource-demanding!)
Give more flexibility in data filtering (as in RDB)
Provide a possibility to work with HITRAN data “offline”
(locally)
Prerequisites
1) Python 2.6+: https://www.python.org/
2) Numpy:
http://www.numpy.org/
License: open source
=> Scientific Python distribution (“Sage”,
“Anaconda” or any other similar distribution)
Download
http://hitran.org/hapi
-
+ Python code
-
+ User guide
Zenodo community (DOI for referencing):
https://zenodo.org/collection/user-hapi
How to use HAPI?
●
Ways of usage:
–
In interactive Python shell
–
In a program (script) as a normal library
Jupyter/IPython
–
How to use HAPI?
●
Ways of usage:
–
In interactive Python shell
–
In a program (script) as a normal library
Jupyter/IPython
–
●
Where to use?
–
Local machine
–
Remote server (cluster, ssh access)
–
Cloud service (Wakari, PythonAnywhere, etc…)
HAPI architecture
USER
Python
API
PLAIN TEXT
XML
HDF5
DATABASE DATABASE DATABASE
LOCAL
HAPI architecture
USER
Python
API
PLAIN TEXT
XML
HDF5
DATABASE DATABASE DATABASE
API functions:
→ absorptionCoefficient_HT(…)
→ partitionSum(…)
→ select(…)
→ describeTable ( … )
→…
LOCAL
HAPI architecture
USER
Python
API
PLAIN TEXT
XML
HDF5
DATABASE DATABASE DATABASE
API functions:
→ absorptionCoefficient_HT(…)
→ partitionSum(…)
→ select(…)
→ describeTable ( … )
→…
LOCAL
REMOTE
HAPI architecture
USER
Python
API
PLAIN TEXT
XML
HDF5
DATABASE DATABASE DATABASE
API functions:
→ absorptionCoefficient_HT(…)
→ partitionSum(…)
→ select(…)
→ describeTable ( … )
→…
LOCAL
REMOTE
Features (1)
●
●
●
●
Fetching data (HITRANonline => local machine)
Filtering and processing the data in SQL-like
fashion
Access to conventional Python structures (lists,
tuples, dictionaries) for representing spectroscopic
data.
Accounting for “non-standard” HITRAN
parameters: speed dependence, Dicke narrowing,
different broadeners etc…
Features (2)
●
●
●
Total internal partition sum (TIPS-2011): R. Gamache
et al. Icarus 215 (2011) 391–400
–
Included information about 51 isotopologues
–
70-3000K temperature range
pCqSDHC line profile: Ngo et al. JQSRT 129 (2013)
89–100 (“Partially Correlated Quadratic Speed
dependent Hard Collision Profile”)
–
a.k.a. Hartmann-Tran profile (HTP)
–
Can be reduced to VP, RP, qSDVP, qSDRP
Codes are rewritten in Python using Numpy library
(fast array operations)
Features (3)
●
●
●
High-resolution spectra simulation accounting for
pressure, temperature and optical path length. The
following spectral functions can be calculated:
–
absorption coefficient
–
absorption spectrum
–
transmittance spectrum
–
radiance spectrum
Spectral calculation using a number of instrumental
functions to simulate experimental spectra.
Possibility to extend the API's functionality by adding
custom line profiles, partition sums and instrumental
functions.
Features (4)
●
Embedded documentation (getHelp)
Data manipulation
●
Similar to SQL (for single table queries)
●
Spectroscopic parameters are stored in tables
●
Display data (~ SQL’s select)
●
Apply filtering conditions (accounting wide range
of expressions on parameters, including regexps)
●
Adding/removing custom parameters
●
Group by parameter/expression
Ipython: Cross section showcase
-
Download data
M I
Range
Ipython: Cross section showcase
-
Filter data
Ipython: Cross section showcase
-
Cross-section calculation
Ipython: Cross section showcase
-
Plotting result
Comment on “Radiative forcings for 28
potential Archean greenhouse gases” Clim.
Past 10, 1779 (2014)
Comment on “Radiative forcings for 28
potential Archean greenhouse gases” Clim.
Past 10, 1779 (2014)
Plans
●
More data formats (XML, JSON, NetCDF …)
●
More profiles (soft collisions, line mixing)
●
●
●
New data storage format (less bulky, more
efficient)
Update partition sums (TIPS-2013)
Add functions for dealing with HITRAN’s
collision-induced absorption cross-sections
Acknowledgements
CfA HITRAN team:
Iouli Gordon, Laurence Rothman, Christian Hill,
Jonas Wilzewski, Piotr Wcisło
NASA Grants: PASCAL, AURA
Newsletter, bug reports, feedback …
●
It’s still work in progress!
●
Please ask your questions
●
Report bugs
[email protected]
… and thanks for your attention!