src/ten/tendHelix.c File Reference

#include "ten.h"
#include "privateTen.h"

Include dependency graph for tendHelix.c:


Defines
#define	INFO "Generate twisting helical tensor field"
#define	WPOS(pos, th) ELL_3V_SET((pos),Rcos(th), Rsin(th), S(th)/(2AIR_PI))
#define	VAL(th) (WPOS(wpos, th), ELL_3V_DIST(wpos, vpos))
#define	RR 0.61803399
#define	CC (1.0-RR)
#define	SHIFT3(a, b, c, d) (a)=(b); (b)=(c); (c)=(d)
#define	SHIFT2(a, b, c) (a)=(b); (b)=(c)
Functions
void	tend_helixDoit (Nrrd *nout, double bnd, double orig[3], double i2w[9], double mf[9], double r, double R, double S, double angle, int incrtwist, double ev[3], double bgEval)
int	tend_helixMain (int argc, char *argv, char me, hestParm *hparm)
	TEND_CMD (helix, INFO)
Variables
char *	_tend_helixInfoL

Define Documentation

#define CC (1.0-RR)

#define INFO "Generate twisting helical tensor field"

#define RR 0.61803399

#define SHIFT2	(	a,
		b,
		c	)	(a)=(b); (b)=(c)

#define SHIFT3	(	a,
		b,
		c,
		d	)	(a)=(b); (b)=(c); (c)=(d)

#define VAL ( th ) (WPOS(wpos, th), ELL_3V_DIST(wpos, vpos))

#define WPOS	(	pos,
		th		)	ELL_3V_SET((pos),Rcos(th), Rsin(th), S(th)/(2AIR_PI))

Function Documentation

TEND_CMD	(	helix	,
		INFO
	)

void tend_helixDoit	(	Nrrd *	nout,
		double	bnd,
		double	orig[3],
		double	i2w[9],
		double	mf[9],
		double	r,
		double	R,
		double	S,
		double	angle,
		int	incrtwist,
		double	ev[3],
		double	bgEval
	)

int tend_helixMain	(	int	argc,
		char **	argv,
		char *	me,
		hestParm *	hparm
	)

Variable Documentation

char* _tend_helixInfoL

Initial value:

  (INFO
   ". The main utility of such a field is to debug handling of coordinate "
   "systems in tensor field visualization.  The \"space directions\" and "
   "\"space origin\" fields of the NRRD header determines the mapping from "
   "coordinates in the index space of the image to coordinates in the "
   "world space in which the image is "
   "sampled.  The \"measurement frame\" field determines the mapping from "
   "the coordinates of the tensor itself, to coordinates of the world space. "
   "When these are correctly handled, the "
   "region of high anisotropy is a right-handed helix (same as DNA). "
   "Using differing axes sizes (via \"-s\") helps make sure that the "
   "raster ordering of axes is correct.  In addition, the tensors twist "
   "relative to the helix, which exposes handling of the measurement frame. "
   "If you trace paths guided by the principal eigenvector of the tensors, "
   "along the surface of the helical cylinder, you get another "
   "right-handed helix, as if the the tensor field is modeling the result "
   "if twisting a set of fibers into single-stranded helical bundle. ")

src/ten/tendHelix.c File Reference

Defines

Functions

Variables

Define Documentation

Function Documentation

Variable Documentation