AstroCalculator 0.1.1

AstroCalculator, a Calculator for Astronomers and Physicists

AstroCalculator, a Calculator for Astronomers and Physicists

About

AstroCalculator is a calculator for astronomers and physicists written in Python.
Author: Chong-Chong He ([e-mail])

Installation

You can install astrocalculator from PyPI:

pip install astrocalculator

astrocalculator is supported on Python 3.6 and above.

How to use

Start the program with calc. You will see a command line interface where you can type in your inputs. A input can be 1) a single variable or constant like k_B, 2) an expression like m_e c^2, or 3) a list of variable assignments followed by a final expression to evaluate, e.g. M = 1.4 M_sun, R = 10 km, sqrt(2 G M / R).

Another way is to use it as a Python module in your script or interactively in iPython. Put the following in your code:

from calc import *

Now you can use all the physical constants defined in astrocalculator as listed in here.

Example inputs and outputs

Input[1]: m_p

Parsed input = m_p
Result (SI)  = 
  Name   = Proton mass
  Value  = 1.67262192369e-27
  Uncertainty  = 5.1e-37
  Unit  = kg
  Reference = CODATA 2018
Result (cgs) = 1.6726e-24 g

Input[2]: m_e c^2

Parsed input = c**2*m_e
Result (SI)  = 8.1871e-14 m N
Result (cgs) = 8.1871e-07 erg

Input[3]: in MeV

0.51100 MeV

Input[4]: M = 1.4 M_sun, R = 10 km, sqrt(2 G M / R)

Parsed input = sqrt(2*G*M*1/R)
Result (SI)  = 1.9277e+08 m / s
Result (cgs) = 1.9277e+10 cm / s

Input[5]: in km/s

1.9277e+05 km / s

Todos

• parse keyword 'in' at the last line and automatically change User Unit.
• Add latex preview

References

• https://docs.astropy.org/en/stable/units/
• https://docs.astropy.org/en/stable/constants/
• https://www.lidavidm.me/blog/posts/2013-09-15-implicit-parsing-in-sympy.html
• https://stackoverflow.com/questions/62507535/python-suppress-expansion-of-exponential-notation-in-parse-expr-sympy