# PHOEBE 2.1 Documentation

## 2.1 Docs

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# Eccentricity (Volume Conservation)¶

## Setup¶

As always, let’s do imports and initialize a logger and a new Bundle. See Building a System for more details.

%matplotlib inline

import phoebe
from phoebe import u # units
import numpy as np
import matplotlib.pyplot as plt

logger = phoebe.logger()

b = phoebe.default_binary()


## Relevant Parameters¶

print b.get(qualifier='ecc')

Parameter: ecc@binary@component
Qualifier: ecc
Description: Eccentricity
Value: 0.0
Constrained by:
Constrains: t0_perpass@binary@component, t0_ref@binary@component, ecosw@binary@component, esinw@binary@component, requiv_max@primary@component, requiv_max@secondary@component
Related to: t0_supconj@binary@component, period@binary@component, per0@binary@component, t0_perpass@binary@component, t0_ref@binary@component, ecosw@binary@component, esinw@binary@component, q@binary@component, syncpar@primary@component, sma@binary@component, incl@primary@component, long_an@primary@component, incl@binary@component, long_an@binary@component, requiv_max@primary@component, syncpar@secondary@component, incl@secondary@component, long_an@secondary@component, requiv_max@secondary@component

print b.get(qualifier='ecosw', context='component')

Parameter: ecosw@binary@component
Qualifier: ecosw
Description: Eccentricity times cos of argument of periastron
Value: 0.0
Constrained by: ecc@binary@component, per0@binary@component
Constrains: None
Related to: ecc@binary@component, per0@binary@component

print b.get(qualifier='esinw', context='component')

Parameter: esinw@binary@component
Qualifier: esinw
Description: Eccentricity times sin of argument of periastron
Value: 0.0
Constrained by: ecc@binary@component, per0@binary@component
Constrains: None
Related to: ecc@binary@component, per0@binary@component


## Relevant Constraints¶

print b.get(qualifier='ecosw', context='constraint')

Constrains (qualifier): ecosw
Expression in SI (value): {ecc@binary@component} * (cos({per0@binary@component}))
Current Result (result): 0.0

print b.get(qualifier='esinw', context='constraint')

Constrains (qualifier): esinw
Expression in SI (value): {ecc@binary@component} * (sin({per0@binary@component}))
Current Result (result): 0.0


## Influence on Meshes (volume conservation)¶

b.add_dataset('mesh', times=np.linspace(0,1,11), columns=['volume'])

<ParameterSet: 4 parameters | contexts: compute, dataset>

b.set_value('ecc', 0.2)

b.run_compute()

<ParameterSet: 68 parameters | components: primary, secondary>

print b['volume@primary@model']

ParameterSet: 11 parameters

afig, mplfig = b['mesh01'].plot(x='times', y='volume', show=True)

b.remove_dataset('mesh01')


b.add_dataset('rv', times=np.linspace(0,1,51))

<ParameterSet: 15 parameters | contexts: compute, dataset>

b.run_compute()

<ParameterSet: 4 parameters | components: primary, secondary>

afig, mplfig = b['rv@model'].plot(show=True)

b.remove_dataset('rv01')


## Influence on Light Curves (fluxes)¶

b.add_dataset('lc', times=np.linspace(0,1,51))

<ParameterSet: 15 parameters | contexts: compute, dataset>

b.run_compute()

<ParameterSet: 2 parameters | qualifiers: fluxes, times>

afig, mplfig = b['lc@model'].plot(show=True)

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Last update: 10/29/2018 9:20 a.m. (CET)