polyserial.c File Reference

Polyserial correlation. More...

#include "libirt.h"
#include <math.h>
#include <gsl/gsl_cdf.h>
#include <gsl/gsl_randist.h>

Functions
double	polyserial_factor (gsl_vector_int *patterns, int nbr_option, int offset, gsl_vector *options_weights)
	Compute the polyserial correlation factor to be multiplied to the point-biserial (pearson) correlation.

Detailed Description

Polyserial correlation.

Author

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

Function Documentation

double polyserial_factor	(	gsl_vector_int *	patterns,
		int	nbr_option,
		int	offset,
		gsl_vector *	options_weights
	)

Compute the polyserial correlation factor to be multiplied to the point-biserial (pearson) correlation.

Parameters

[in]	patterns	A vector(subjects) with the responses.
[in]	nbr_option	The number of option..
[in]	offset	The value of the forst option.
[in]	options_weights	The weights of each option.

If there is no weights or the weights are not strictly increasing or there is only two options, then the biserial correlation factor is calculated (i.e. the response are corrected with the option having the biggest weight.

Returns

The polyserial correlation factor.