From 1d8280961cf95887dc532da56ea595e097889b38 Mon Sep 17 00:00:00 2001
From: Aaron LI <aly@aaronly.me>
Date: Tue, 15 Aug 2017 10:22:08 +0800
Subject: cosmo_calc.py: Use variables H0, Om0, pixelsize
TODO: add argument --pixelsize with default value of 0.492 [arcsec]
---
bin/cosmo_calc.py | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/bin/cosmo_calc.py b/bin/cosmo_calc.py
index 1302bdb..3f0b81f 100755
--- a/bin/cosmo_calc.py
+++ b/bin/cosmo_calc.py
@@ -74,15 +74,22 @@ def calc_quantity(q, calculator, args):
def main():
+ # Hubble parameter at present day
+ H0 = 71.0 # [km/s/Mpc]
+ # Present-day matter density
+ Om0 = 0.27
+ # Chandra ACIS pixel size
+ pixelsize = 0.492 # [arcsec]
+
parser = argparse.ArgumentParser(
description="Cosmology calculator with Chandra-specific quantities")
parser.add_argument("-H", "--hubble", dest="H0",
- type=float, default=71.0,
+ type=float, default=H0,
help="Present-day Hubble parameter " +
- "(default: 71 km/s/Mpc)")
+ "(default: %s [km/s/Mpc])" % H0)
parser.add_argument("-M", "--omega-m", dest="Om0",
- type=float, default=0.27,
- help="Present-day matter density (default: 0.27")
+ type=float, default=Om0,
+ help="Present-day matter density (default: %s)" % Om0)
parser.add_argument("-b", "--brief", dest="brief", action="store_true",
help="be brief")
parser.add_argument("-U", "--unit", dest="unit",
@@ -102,11 +109,11 @@ def main():
parser.add_argument("--kpc-per-pix", dest="kpc_per_pix",
action="store_true",
help="calculate the transversal length [kpc] " +
- "w.r.t. 1 ACIS pixel (0.492 arcsec) at DA(z)")
+ "w.r.t. 1 pixel (%s [arcsec]) at DA(z)" % pixelsize)
parser.add_argument("--cm-per-pix", dest="cm_per_pix",
action="store_true",
help="calculate the transversal length [cm] " +
- "w.r.t. 1 ACIS pixel (0.492 arcsec) at DA(z)")
+ "w.r.t. 1 pixel (%s [arcsec]) at DA(z)" % pixelsize)
parser.add_argument("--norm-apec", dest="norm_apec",
action="store_true",
help="calculate the normalization factor " +
--
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