Model Functions

Code to define the models and model parameters for the gp regression.

class src.magpy_rv.models.Keplerian(time, model_params)[source]

The generalized Keplerian RV model (only use when dealing with RV observation of star with possible planet).

Parameters
  • time (array, floats) – Time array over which to compute the Keplerian.

  • model_params (dictionary) –

    Dictionary of model parameters containing:
    Pfloat

    Period of orbit in days.

    Kfloat

    Semi-aplitude of the rv signal in meter per seconds.

    eccfloat

    Eccentricity of orbit. Float between 0 and 0.99

    omegafloat

    Angle of periastron, in rad.

    t0float

    Time of periastron passage of a planet

ecc_anomaly(M, ecc, max_itr=200)[source]
Parameters
  • M (float) – Mean anomaly

  • ecc (float) – Eccentricity, number between 0. and 0.99

  • max_itr (integer, optional) – Number of maximum iteration in E computation. The default is 200.

Returns

E – Eccentric anomaly

Return type

float

model()[source]
Returns

rad_vel – Radial volicity model derived by the number of planet include

Return type

array, floats

static numb_param()[source]

Returns the number of parameters

static params(model_num=None, plotting=True, SkCk=False)[source]

Function to return a list of the parameters in selected format

Parameters
  • model_num (int, optional) – indicates the nth of this model in the model list, defaults to None

  • plotting (bool, optional) – True returns the list in format for plots, False returns the list in format for text, defaults to True

  • SkCk (bool, optional) – If True return list including Sk and Ck, if False return list including ecc and omega, defaults to False

true_anomaly(E, ecc)[source]
Parameters
  • E (float) – Eccentric anomaly

  • ecc (float) – Eccentricity

Returns

nu – True anomaly

Return type

float

class src.magpy_rv.models.Model[source]

Parent class for all models. All new models should inherit from this class and follow its structure. Each new model will require a __init__() method to override the parent class. In the __init__ function, call the neccesary parameters.

abstract model()[source]

computes the model, returning model_y

abstract static numb_param()[source]

returns the number of model parameters

abstract static params(model_num=None, plotting=True)[source]

returns the list of model parameters

class src.magpy_rv.models.No_Model(y, no)[source]

The subtracted model from the RV is null

Parameters

y (array) – Observed RV or ys

model()[source]
Returns

model_y – Model y to subtract from the observations

Return type

array

static numb_param()[source]

Returns the number of parameters

static params(model_num=None, plotting=True)[source]

Function to return a list of the parameters in selected format

Parameters
  • model_num (int, optional) – indicates the nth of this model in the model list, defaults to None

  • plotting (bool, optional) – True returns the list in format for plots, False returns the list in format for text, defaults to True

class src.magpy_rv.models.Offset(flags, model_params)[source]

The subtracted model from RV is a constant offset chosen explicitlty

Parameters
  • flags (array of floats) – array of flags representing which datapoints in the time array are related to which telescope and so will have which offset generated by the combine_data function

  • model_params (dictionary of model parameters) – dictionary containing the offset model parameter

Raises

Assertion: – Raised if model parameters is longer than 1

model()[source]
Returns

model_y – Model y to subtract from the observations

Return type

array

static numb_param()[source]

Returns the number of parameters

static params(model_num=None, plotting=True)[source]

Function to return a list of the parameters in selected format

Parameters
  • model_num (int, optional) – indicates the nth of this model in the model list, defaults to None

  • plotting (bool, optional) – True returns the list in format for plots, False returns the list in format for text, defaults to True

class src.magpy_rv.models.Polynomial(time, model_params)[source]

The model of the rv data follows a polynomial up to the 3rd degree with equation:

\[a_3(time)^3 + a_2(time)^2 + a_1(time) + a_0\]
Parameters
  • time (array) – Time or x axis array

  • model_params (dictionary of model parameters) – containing a0, a1, a2, a3

Raises

Assertion: – Raised if the model does not have 4 model parameters

model()[source]
Returns

model_y – Model y to subtract from the observations

Return type

array

static numb_param()[source]

Returns the number of parameters

static params(model_num=None, plotting=True)[source]

Function to return a list of the parameters in selected format

Parameters
  • model_num (int, optional) – indicates the nth of this model in the model list, defaults to None

  • plotting (bool, optional) – True returns the list in format for plots, False returns the list in format for text, defaults to True

src.magpy_rv.models.combine_data(times, ys, y_errs)[source]

Function to combine data from multiple telescopes to an X and Y array and generate an array of flags for the offsets

Parameters
  • times (list or tuple of arrays of floats) – list of the time arrays from the telescopes where the first array in the list is the zero point offset

  • ys (list or tuple of arrays of floats) – list of the rv arrays from the telescopes where the first array in the list is the zero point offset, arrays entered into list in same order as times

  • y_errs (list or tuple of arrays of floats) – list of the rv error arrays from the telescopes where the first array in the list is the zero point offset, arrays entered into list in same order as times

Raises
  • Assertion: – Raised if times is not a list or tuple

  • Assertion – Raised if ys is not a list or tuple

  • Assertion – Raised if y_errs is not a list or tuple

Returns

  • time (array of floats) – combined time array of all telescopes

  • y (array of floats) – combined rv array of all telescopes

  • y_err (array of floats) – combined rv error array of all telescopes

  • flags (array of floats) – array of flags representing which datapoints in the time array are related to which telescope and so will have which offset

src.magpy_rv.models.defModelList()[source]

Function to return the list of all currently available Models

src.magpy_rv.models.mod_create(model)[source]

Function to generate a dictionary of necessary model parameters for the chosen models

Parameters

model (string or list of strings) – name of the desired model or list of the model names

Raises

ValueError: – Raised if the model is not a string or list of strings

Returns

model_params – Dictionary of all necessary parameters

Return type

dictionary