from numpy import sin, cos, zeros
import fkepler
fkepler.settol(1.e-5)
def v_rad(K, tau, e, long, T0, v0, times):
"""
Calculate the radial (line-of-sight) velocity for a Keplerian orbit
as a function of orbital parameters, COM velocity, and time. The
parameters are:
K = velocity amplitude
tau = period
e = eccentricity
long = longitude of periastron (radians)
T0 = time of periastron crossing
v0 = COM velocity
The times argument can be either a single float (with the velocity
returned as a float) or an array of floats (with the velocity
returned as a corresponding array).
tau, T0 and times should be in the same units (typically days).
K can use a different unit of time (typically m/s).
"""
fkepler.setup_Tp(tau, e, T0)
if type(times)==float:
c, s = fkepler.t2TA(times) # Get cos, sin of true anomaly
else:
c, s = fkepler.vt2TA(times)
return v0 + K*cos(long)*(e+c) + K*sin(long)*s
import string from math import * from scipy import zeros, ones, Float, sum from scipy import random as r import fkepler fkepler.settol(1.e-3) def Kepler_setup(tau, e, T0, times): global cs_vals fkepler.setup(tau, e, T0) return fkepler.vt2TA(times) def Kepler0(tau, e, T0, times, cs_vals): return ones(len(times), Float) def Kepler1(tau, e, T0, times, cs_vals): return e + cs_vals[:,0] def Kepler2(tau, e, T0, times, cs_vals): return cs_vals[:,1] def phaseCurve(ofile, tau, e, T0, amps, data, n, sigma=None): """Write data for plotting a velocity curve against observations. The data are written as phases in [0,1), and the curve is written as n phases in [-.5, 1.5] and the corresponding velocities. Return chi**2 for the curve.""" # First, make the curve. dt = 2./(n-1) phases = zeros(n, Float)
import string
from math import *
from scipy import zeros, ones, Float, sum
from scipy import random as r
import fkepler
fkepler.settol(1.e-3)
def Kepler_setup(tau, e, T0, times):
global cs_vals
fkepler.setup(tau, e, T0)
return fkepler.vt2TA(times)
def Kepler0(tau, e, T0, times, cs_vals):
return ones(len(times), Float)
def Kepler1(tau, e, T0, times, cs_vals):
return e + cs_vals[:, 0]
def Kepler2(tau, e, T0, times, cs_vals):
return cs_vals[:, 1]
def phaseCurve(ofile, tau, e, T0, amps, data, n, sigma=None):
"""Write data for plotting a velocity curve against observations.
The data are written as phases in [0,1), and the curve is written
as n phases in [-.5, 1.5] and the corresponding velocities.
from numpy import sin, cos, zeros
import fkepler
fkepler.settol(1.e-5)
def v_rad(K, tau, e, long, T0, v0, times):
"""
Calculate the radial (line-of-sight) velocity for a Keplerian orbit
as a function of orbital parameters, COM velocity, and time. The
parameters are:
K = velocity amplitude
tau = period
e = eccentricity
long = longitude of periastron (radians)
T0 = time of periastron crossing
v0 = COM velocity
The times argument can be either a single float (with the velocity
returned as a float) or an array of floats (with the velocity
returned as a corresponding array).
tau, T0 and times should be in the same units (typically days).
K can use a different unit of time (typically m/s).
"""
fkepler.setup_Tp(tau, e, T0)
if type(times) == float:
c, s = fkepler.t2TA(times) # Get cos, sin of true anomaly
else:
c, s = fkepler.vt2TA(times)
return v0 + K * cos(long) * (e + c) + K * sin(long) * s
