Getting started

Data, models, and results

To get started, read in a dataset and choose one of the available models:

import kima
from kima import RVData, RVmodel

data = RVData('my_dataset')

model = RVmodel(fix=True, npmax=1, data=data)

and then run the model

kima.run(model, steps=1000)

The resulting posteriors can be loaded and analysed easily (more information here)

res = kima.load_results(model)
res.plot_posterior_periods()

Running the examples

kima comes packed with ready-to-run examples. All of them are described to some length here.

Finding 51 Peg b

One of the examples involves the detection of 51 Peg b in Keck/HIRES data. Running it is as simple as

from kima.examples import _51Peg

model, res = _51Peg(run=True, load=True) #(1)

1. This will run kima for 5000 steps, taking a few seconds.

and the results object provides a number of useful plots

res.plot_posterior_np() #(1)

res.plot_posterior_periods() #(2)

p = res.maximum_likelihood_sample() #(3)
res.phase_plot(p) #(4)

1. shows the posterior for the number of planets
2. shows the posterior for the orbital period, with a clear peak at 4.23 days
3. select the sample with the maximum likelihood value
4. plot the maximum likelihood solution in phase

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