NAME : pyCOSMOCAL
TASK : Ned Wright Cosmology Calculator [http://www.astro.ucla.edu/~wright/CosmoCalc.html] with Graphic User Interface
AUTHORS : Bhargav Vaidya [University of Leeds]
DESCRIPTION: The code is completely written using the Python Language. The original python code for the non gui version is adapted from CC.py by James Schombert. Further the GUI is developed with the Tkinter Interface.
FEATURES: The GUI environment provides a similar work flow structure like the Java Script HMTL CosmoCalc developed by Wright 2006.
QUICK START : After sucessful installation and careful inclusion of required path in the PATH variable, one would be able to invole the command ./CosmoCal.py. If no flags are provided the command would by default show the required syntax. SYNTAX: python ComsoCal.py The flag can be either of these two: = -gui : This invoked the Graphic User Interface Option [Requires Python Tkinter] = -ngui z (H0 WM WV) : This invokes the normal Python Interface
Thus, in order to start the Calculator in GUI form invoke the command vaidya@home> ./CosmoCal.py -gui
This will prompt a Tkinter Window which has similar functionality of the JavaScript Calculator.
In order to work in Non GUI format, there are basically two methods.
- Command Line Option: vaidya@home> ./CosmoCal.py -ngui z (H0, WM, WV)
If no arguments are provided after the '-ngui' flag the resultant output will remind the user the correct syntax i.e.
With -ngui flag the syntax is python CosmoCal -ngui z (H0 WM WV) REQUIRED ARGS : z - Redshift OPTIONAL ARGS : H0 - Hubble Constant in km/s/Mpc [ DEFAULT = 71.0 km/s/Mpc] WM - Omega Matter [DEFAULT = 0.27] WV - Omega Vaccum. [DEFAULT = 1.0 - WM - 0.4165/(H0*H0)]
As mentioned the value of redshift is essential else the code will not function and prompt for a valid value of z. The other quantities are optional if these values are not provided the code assumes default values as indicated above.
2.Using python (or IPython) prompt: One can also use the Python (or IPython) prompt in the manner described below,
vaidya@home> python Enthought Python Distribution -- www.enthought.com Version: 7.2-1 (64-bit)
Python 2.7.2 |EPD 7.2-1 (64-bit)| (default, Jul 27 2011, 14:50:45) [GCC 4.0.1 (Apple Inc. build 5493)] on darwin Type "packages", "demo" or "enthought" for more information.
import cosmocal_nongui as cc Out_Dict = cc.CC_nongui(3.0,71.0,0.27,0.73) from pprint import pprint pprint(Out_Dict) {'DA_Gyr': 5.2678075619641413, 'DA_Mpc': 1615.1042925672091, 'DCMR_Gyr': 21.071909562803281, 'DCMR_Mpc': 6460.6254475214764, 'DL_Gyr': 84.284920991426262, 'DL_Mpc': 25841.668681075345, 'DMod': 47.061602770219039, 'DTT_Gyr': 11.47608214682462, 'V_Gpc': 1129.5240939432965, 'age_Gyr': 13.665696769001471, 'kpc_DA': 7.8302465839335147, 'zage_Gyr': 2.1896146221768507}
Thus the output is stored in form of a Dictionary with keys described below, DA : Angular Distance [_Gyr in Giga Year, _Mpc in Mega Parsec, _kpc in kiloparsec] DCMR : Comoving radial distance [_Gyr in Giga Year, _Mpc in Mega Parsec] DL : Luminosity Distance [_Gyr in Giga Year, _Mpc in Mega Parsec] DMod : Distance modulus DTT : Time from z to now V_Gpc : Comoving volume within redshift in Gpc3. age_Gyr: Age of Universe in Gyr zage_Gyr: Age of Universe at redshift z in Gyr