crescent_image_comparison_themistan.cpp File Reference

Fits a crescent model to visibility amplitude data using the deo tempering sampler with the stan exploration kernel. This is a validation and test for it. More...

Include dependency graph for crescent_image_comparison_themistan.cpp:

Functions

int main (int argc, char *argv[])
 

Detailed Description

Author
Jorge A. Preciado, Paul Tiede
Date
April, 2020

Compares a geometric crescent model to the visibility amplitude data taken in 2007 and 2009, permitting a day-specific intensity renormalization. The primary fit result is a measure of the size ( \( R \)), the relative thickness ( \( \psi \)), and the degree of symmetry ( \( \tau \)) of the emission region and can be compared to the fit results reported in Kamruddin and Dexter 2013.

The resulting parameter distribution is:

Crescent-Triangle.png
Triangle plot for the marginalized posterior probabilty distribution showing the likely parameter values and associated confidence contours.


Note that the intensity normalization is solved for analytically in the likelihood_marginalized_visibility_amplitude, and thus the intrinsic normalization is fixed near unity by design.

Author
Jorge A. Preciado, Paul Tiede
Date
April, 2020

Compares a geometric crescent model to the visibility amplitude data taken in 2007 and 2009, permitting a day-specific intensity renormalization. The primary fit result is a measure of the size ( \( R \)), the relative thickness ( \( \psi \)), and the degree of symmetry ( \( \tau \)) of the emission region and can be compared to the fit results reported in Kamruddin and Dexter 2013.

The resulting parameter distribution is:

Crescent-Triangle.png
Triangle plot for the marginalized posterior probabilty distribution showing the likely parameter values and associated confidence contours.


Note that the intensity normalization is solved for analytically in the likelihood_marginalized_visibility_amplitude, and thus the intrinsic normalization is fixed near unity by design.

The parameter values associated with the individual chains are:

Crescent-Trace.png
Trace plot showing the fluctuations in the parameters for each MCMC chain as a function of MCMC step.


The associated likelihoods and \(\chi^2\) of the chains are:

Crescent-Likelihood.png
Log-likelihoods of the individual chains as a function of MCMC step.
Crescent-Chi-squared.png
Chi-squared of the individual chains output periodically throughout the MCMC run.
See also
See reading_data.cpp example for details on reading in EHT data.