#include <math.h>
#include <syslog.h>
#include <gsl/gsl_blas.h>
#include <barrett/cdlbt/spline.h>
#include <barrett/cdlbt/interp.h>

Functions
int	bt_spline_create (struct bt_spline *splineptr, const gsl_vector start, enum bt_spline_mode mode)
int	bt_spline_add (struct bt_spline spline, const gsl_vector vec, double s)
int	bt_spline_init (struct bt_spline spline, gsl_vector start, gsl_vector *direction)
int	bt_spline_destroy (struct bt_spline *spline)
int	bt_spline_get (struct bt_spline spline, gsl_vector result, double s)

Detailed Description

Implementation of bt_spline, an n-dimensional vector interpolator.

Author:: Christopher Dellin

Date:: 2008-2009

Function Documentation

int bt_spline_add	(	struct bt_spline *	spline,
		const gsl_vector *	vec,
		double	s
	)

Add a point to a bt_spline.

This function is called iteratively once a bt_spline has been created to add points to the end of the spline. If the mode is BT_SPLINE_MODE_EXTERNAL, care must be take to ensure that the parameter s is monotonically increasing. If the mode is BT_SPLINE_MODE_ARCLEN, the s parameter is ignored.

Parameters:

[in]	spline	The bt_spline object to which to add the point
[in]	vec	The point to add
[in]	s	The values of the external parameter at this point

Return values:

0 Success

int bt_spline_create	(	struct bt_spline **	splineptr,
		const gsl_vector *	start,
		enum bt_spline_mode	mode
	)

This file is part of libbarrett.

This version of libbarrett is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This version of libbarrett is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this version of libbarrett. If not, see <http://www.gnu.org/licenses/>.

Barrett Technology Inc. 73 Chapel Street Newton, MA 02458

int bt_spline_destroy ( struct bt_spline * spline )

Destroy a bt_spline object.

This function destroys a bt_spline object created by bt_spline_create().

Parameters:

[in] spline The bt_spline object to destroy

Return values:

0 Success

int bt_spline_get	(	struct bt_spline *	spline,
		gsl_vector *	result,
		double	s
	)

Retrieve the interpolated vector at a given parameter value.

This function is designed to be called in a control loop to retrieve the interpolated vector at the paramater value s.

Parameters:

[in]	spline	The bt_spline object to use
[in]	result	The vector at the given paramter value
[in]	s	The parameter value to use

Return values:

0 Success

int bt_spline_init	(	struct bt_spline *	spline,
		gsl_vector *	start,
		gsl_vector *	direction
	)

Initialize the bt_spline after adding all points.

Once points are added to the spline using bt_spline_add(), the spline is initialized. This will create the interpolating objects for each dimension. If the start argument is passed, the original starting point given in bt_spline_create() will be replaced before any calculations take place. If the direction argument is passed, the initial slopes to each interpolator will be proportional to the normalized direction vector's values.

Note:: The direction vector, if passed and non-zero, will be normalized in place.

Parameters:

[in]	spline	The bt_spline object to initialize
[in]	start	A vector to replace the original start vector with, or 0 to skip this step
[in]	direction	A vector to use as the direction of the new spline

Return values:

0 Success

Functions

Detailed Description

Function Documentation