from __future__ import division

import quantities as pq
import numpy as np
import inspect

# This IPython magic generates a table with version information
#https://github.com/jrjohansson/version_information
%load_ext version_information
%version_information numpy, quantities

x = 3 * pq.m
y = 5 * pq.foot
print x + y

x = 3.5 * pq.newton
y = 0.7 * pq.joule
try:
    x + y # we get an error if the operation is invalid with this units
except Exception as e:
    print u'*** Attention! ***: ',e

x = 0.3 * pq.km    # length in Km
t = 250 * pq.ms     # time in milliseconds
accel = x/t**2
mass = 7 * pq.g  # mass in grams
force = mass * accel
print force

print force.simplified

print force.rescale(pq.newton)
print force.rescale(pq.dyne)

# Time and distance units
print pq.year # time in years
print pq.au, pq.au.simplified # distance in astronomical units
print pq.light_year, pq.light_year.simplified # distance in light-years
print pq.pc, pq.pc.simplified # distance in parsecs

# Temperature units
print pq.K
print pq.celsius

# In this example we see that the conversion is not performed
temp = 345 * pq.celsius
print temp.rescale(pq.K)

# Neither is correct the conversion between Farhrenheit and Celsius scales
# However, if the value is considered as an increase in temperature,
# then, the result is the correct answer
temp = 170 * pq.fahrenheit
print temp.rescale(pq.celsius)

# Measurement of angles
print pq.deg
print pq.rad
print pq.arcmin
print pq.arcsec

print (np.pi/2 * pq.rad).rescale(pq.deg)

print (1 * pq.deg).rescale(pq.arcmin)

# Definition of new units
Mly = pq.UnitQuantity('megalight_year', 1e6*pq.ly, symbol = 'Mly')
Mpc = pq.UnitQuantity('megaparsec', 1e6*pq.pc, symbol = 'Mpc')

print (1 * Mpc).rescale(pq.ly)

print pq.c, pq.c.simplified # Speed of light
print pq.constants.G, pq.constants.G.simplified # Newtonian constant of gravitation

# Definition of new constants:
earth_radius = 6378160.0 * pq.m
moon_radius = 1740000.0 * pq.m
sun_radius = 695000000.0 * pq.m
earth_mass =  5.97219e24 * pq.kg
sun_mass = 332946 * earth_mass
Hubble_constant = 67.80 * (pq.km/pq.s)/(1e6*pq.pc)

xa = np.arange(10) * pq.N

print xa[5]

print (xa / (3.0 * pq.kg)).simplified

# A single numerical value
f = 30 * pq.N
print f.item(), type(f.item())

# An array of values
print xa.magnitude, type(f.magnitude)

for nombre, datos  in inspect.getmembers(pq.units, inspect.ismodule):
    print nombre, ',',

for u in dir(pq.mass):
    print u,',',

for nombre, datos in inspect.getmembers(pq.constants, inspect.ismodule):
    print nombre, ',',

dir(pq.constants.astronomy)