eap_ability.c File Reference

Functions to estimate the abilities by EAP. More...

#include "libirt.h"
#include <stdio.h>
#include <math.h>

Functions
void	eap_abilities (gsl_matrix *post, gsl_vector *quad_points, gsl_vector *quad_weights, gsl_vector *abilities, gsl_vector *abilities_stddev)
	Estimate the abilities by Bayes exact a posteriori.

Detailed Description

Functions to estimate the abilities by EAP.

Author

Stephane Germain germs.nosp@m.te@g.nosp@m.mail..nosp@m.com

Function Documentation

void eap_abilities	(	gsl_matrix *	post,
		gsl_vector *	quad_points,
		gsl_vector *	quad_weights,
		gsl_vector *	abilities,
		gsl_vector *	abilities_stddev
	)

Estimate the abilities by Bayes exact a posteriori.

Work also for expanded multiple choices patterns.

Parameters

[in]	post	A matrix(patterns x classes) with the probability that a pattern is in a quadrature class.
[in]	quad_points	A vector(classes) with the middle points of each quadrature class.
[in]	quad_weights	A vector(classes) with the prior weights of each quadrature class.
[out]	abilities	A vector(patterns) with the estimated abilities.
[out]	abilities_stddev	A vector(items) with the standard errors of the estimated abilities.

Warning

The memory for abilities and abilities_stddev should be allocated before.