regression.c File Reference

Routines for finding the best fit line through a set of points. More...

#include <math.h>
#include <stdlib.h>
#include "pdb.h"
#include "array.h"
#include "macros.h"
#include "MathType.h"
#include "SysDefs.h"
#include "regression.h"
#include "eigen.h"

Go to the source code of this file.

Functions
BOOL	blCalculateBestFitLine (REAL **coordinates, int numberOfPoints, int numberOfDimensions, REAL *centroid, REAL *eigenVector)
void	blFindCentroid (REAL **matrix, int numX, int numY, REAL *centroid)
BOOL	blCalculateCovarianceMatrix (REAL **matrix, int numX, int numY, REAL **cov)

Detailed Description

Routines for finding the best fit line through a set of points.

Version

V1.0

Date

08.10.14

Copyright

(c) Dr. Andrew C. R. Martin, UCL, 2014

Author

Dr. Andrew C. R. Martin

Institute of Structural & Molecular Biology, University College London, Gower Street, London. WC1E 6BT.

andre.nosp@m.w@bi.nosp@m.oinf..nosp@m.org..nosp@m.uk andre.nosp@m.w.ma.nosp@m.rtin@.nosp@m.ucl..nosp@m.ac.uk

This program is not in the public domain, but it may be copied according to the conditions laid out in the accompanying file COPYING.DOC

The code may not be sold commercially or included as part of a commercial product except as described in the file COPYING.DOC.

Description:

Usage:

Revision History:

• V1.0 08.10.14 Original By: ACRM Based on code by Abhi Raghavan

Definition in file regression.c.

Function Documentation

BOOL blCalculateBestFitLine	(	REAL **	coordinates,
		int	numberOfPoints,
		int	numberOfDimensions,
		REAL *	centroid,
		REAL *	eigenVector
	)

Parameters

[in]	coordinates	2D Array containing the coordinates
[in]	numberOfPoints	The number of points in the array
[in]	numberOfDimensions	The number of dimensions (usually 3)
[out]	centroid	The centroid of the points
[out]	eigenVector	The best Eigen vector

Returns

Success?

Calculates a best fit line through a set of coordinates in 3D. The results are returned in 'eigenVector'

The code calculates the centroid and ouputs this. The covariance matrix is then calculated and the Eigen vectors and values of the covariance matrix are then calculated. The Eigenvalue with the largest Eigenvector represents the best fit line passing through the centroid.

• 07.10.14 Original By: ACRM Based on code by Abhi Raghavan

Definition at line 116 of file regression.c.

BOOL blCalculateCovarianceMatrix	(	REAL **	matrix,
		int	numX,
		int	numY,
		REAL **	cov
	)

Parameters

[in]	matrix	The matrix
[in]	numX	x-dimension of the matrix
[in]	numY	y-dimension of the matrix
[out]	cov	The covariance matrix

Returns

Success

Find the covariance matrix for a given matrix

• 07.10.14 Original By: ACRM (based on code by Abhi Raghavan)

Definition at line 254 of file regression.c.

void blFindCentroid	(	REAL **	matrix,
		int	numX,
		int	numY,
		REAL *	centroid
	)

Parameters

[in]	matrix	Coordinate array
[in]	numX	The x-dimension of the array
[in]	numY	The y-dimension of the array
[out]	centroid	The centroid of the points

Calculates the centroid of an array of points

• 07.10.14 Original By: ACRM

Definition at line 215 of file regression.c.