include/barrett/cdlbt/interp.h File Reference

#include <gsl/gsl_interp.h>

Go to the source code of this file.

Enumerations
enum	bt_interp_type { BT_INTERP_NATURAL, BT_INTERP_SLOPE }
Functions
int	bt_interp_set_type (gsl_interp *interp, enum bt_interp_type ltype, enum bt_interp_type rtype)
int	bt_interp_set_slopes (gsl_interp *interp, double lslope, double rslope)
Variables
const gsl_interp_type *	bt_interp

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Detailed Description

Definition of bt_interp, GSL interpolator type with support for 2-point trajectories, as well as natural or slope-drive endpoints.

Author:

Christopher Dellin

Date:

2008-2009

Copyright 2009-2014 Barrett Technology <support@barrett.com>

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

Introduction

A bt_interp type is a GSL interpolator type based on GSL's interpolation framework. For more information about this framework, see the "Interpolation" subsection of the GSL manual, located here: <http://www.gnu.org/software/gsl/manual/html_node/Interpolation.html>

A bt_interp type is similar to the standard GSL gsl_interp_cspline cubic spline type, with a number of enhancements.

First, while a gsl_interp_cspline has a minimum number of 3 points, a bt_interp also supports 2-point (linear) trajectories.

Second, while a gsl_interp_cspline only supports natural boundary conditions (i.e. zero-concavity), a bt_interp also supports explicitly setting the slope at either endpoint.

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Enumeration Type Documentation

enum bt_interp_type

The type of a bt_interp endpoint, either natural or slope.

An endpoint of type BT_INTERP_NATURAL has a zero concavity (or second-derivative), while an endpoint of type BT_INTERP_SLOPE has an explicitly defined slope at the endpoint.

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Function Documentation

int bt_interp_set_slopes	(	gsl_interp *	interp,
		double	lslope,
		double	rslope
	)

This function is used to set the explicit slopes of the two endpoints before the interpolator is initialized.

Note:

The values specified here will only be used if the endpoint is also of type BT_INTERP_SLOPE.

int bt_interp_set_type	(	gsl_interp *	interp,
		enum bt_interp_type	ltype,
		enum bt_interp_type	rtype
	)

This function is used to set the types of the two endpoints before the interpolator is initialized.

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Variable Documentation

const gsl_interp_type* bt_interp

This is the GSL interpolator type object to be used with gsl_interp_alloc() when a bt_interp type is to be used.