gblsit3.gblSimpleHelix Class Reference

Simple helix. More...

Inheritance diagram for gblsit3.gblSimpleHelix:

Public Member Functions
def	__init__ (self, parameter)
	Constructor. More...
def	getPrediction (self, refPos, uDir, vDir)
	Get prediction. More...
def	getArcLengthXY (self, xPos, yPos)
	Get (2D) arc length for given point. More...
def	moveTo (self, newRefPoint)
	Change reference point. More...

Private Attributes
	__rinv
	curvature (in XY) More...
	__phi0
	flight direction at point of closest approach (in XY) More...
	__dir0
	direction vector at point of closest approach (in XY) More...
	__dca
	distance of closest approach in (XY) More...
	__dzds
	dZ/ds More...
	__z0
	Z position at distance of closest approach. More...
	__xRelCenter
	XY circle parameter: X position of center / R. More...
	__yRelCenter
	XY circle parameter: Y position of center / R. More...

Detailed Description

Simple helix.

Assuming constant magnetic field in (positive) Z-direction

Definition at line 434 of file gblsit3.py.

Constructor & Destructor Documentation

__init__()

def gblsit3.gblSimpleHelix.__init__	(		self,
			parameter
	)

Constructor.

Parameters

[in]

parameter

helix parameter (curv, phi0, dca, dzds, z0); list

For comparison: Generalized circle equation: n_0 + x*n_1 + y*n_2 + (x*x+y*y)*n_3 = 0, n_0 ~= -dca, (n_1, n_2) = -(cos(phi_0), sin(phi_0)), n_3 = 0.5*rinv

Definition at line 444 of file gblsit3.py.

Member Function Documentation

getArcLengthXY()

def gblsit3.gblSimpleHelix.getArcLengthXY	(		self,
			xPos,
			yPos
	)

Get (2D) arc length for given point.

Arc length from dca to point on circle on intersection with line from circle center to given point

Parameters

[in]	xPos	X Position; float
[in]	yPos	Y Position; float

Returns

arc length from dca to point on circle; float

Definition at line 522 of file gblsit3.py.

References gblsit3.gblSimpleHelix.__dir0, gblsit3.gblSimpleHelix.__phi0, gblsit3.gblSimpleHelix.__rinv, gblsit3.gblSimpleHelix.__xRelCenter, and gblsit3.gblSimpleHelix.__yRelCenter.

Referenced by gblsit3.gblSimpleHelix.getPrediction().

getPrediction()

def gblsit3.gblSimpleHelix.getPrediction	(		self,
			refPos,
			uDir,
			vDir
	)

Get prediction.

Get prediction from intersection of helix with measurement plane.

Parameters

[in]	refPos	reference position on detector plane; vector
[in]	uDir	measurement direction 'u'; vector
[in]	vDir	measurement direction 'v'; vector

Returns

prediction; class

Definition at line 471 of file gblsit3.py.

References gblsit3.gblSimpleHelix.__dca, gblsit3.gblSimpleHelix.__dir0, gblsit3.gblSimpleHelix.__dzds, gblsit3.gblSimpleHelix.__phi0, gblsit3.gblSimpleHelix.__rinv, gblsit3.gblSimpleHelix.__xRelCenter, gblsit3.gblSimpleHelix.__yRelCenter, gblsit3.gblSimpleHelix.__z0, and gblsit3.gblSimpleHelix.getArcLengthXY().

moveTo()

def gblsit3.gblSimpleHelix.moveTo	(		self,
			newRefPoint
	)

Change reference point.

Parameters

[in]

newRefPoint

new reference point (in XY); vector

Returns

new helix parameters; list

Based on V. Karimaki, NIM A305 (1991) 187-191, eqn (19)

Definition at line 540 of file gblsit3.py.

References gblsit3.gblSimpleHelix.__dca, gblsit3.gblSimpleHelix.__dir0, gblsit3.gblSimpleHelix.__dzds, gblsit3.gblSimpleHelix.__phi0, gblsit3.gblSimpleHelix.__rinv, and gblsit3.gblSimpleHelix.__z0.

Member Data Documentation

__dca

gblsit3.gblSimpleHelix.__dca

private

distance of closest approach in (XY)

Definition at line 452 of file gblsit3.py.

Referenced by gblsit3.gblSimpleHelix.getPrediction(), and gblsit3.gblSimpleHelix.moveTo().

__dir0

gblsit3.gblSimpleHelix.__dir0

private

direction vector at point of closest approach (in XY)

Definition at line 450 of file gblsit3.py.

Referenced by gblsit3.gblSimpleHelix.getArcLengthXY(), gblsit3.gblSimpleHelix.getPrediction(), and gblsit3.gblSimpleHelix.moveTo().

__dzds

gblsit3.gblSimpleHelix.__dzds

private

dZ/ds

Definition at line 454 of file gblsit3.py.

Referenced by gblsit3.gblSimpleHelix.getPrediction(), and gblsit3.gblSimpleHelix.moveTo().

__phi0

gblsit3.gblSimpleHelix.__phi0

private

flight direction at point of closest approach (in XY)

Definition at line 448 of file gblsit3.py.

Referenced by gblsit3.gblSimpleHelix.getArcLengthXY(), gblsit3.gblSimpleHelix.getPrediction(), and gblsit3.gblSimpleHelix.moveTo().

__rinv

gblsit3.gblSimpleHelix.__rinv

private

curvature (in XY)

Definition at line 446 of file gblsit3.py.

Referenced by gblsit3.gblSimpleHelix.getArcLengthXY(), gblsit3.gblSimpleHelix.getPrediction(), and gblsit3.gblSimpleHelix.moveTo().

__xRelCenter

gblsit3.gblSimpleHelix.__xRelCenter

private

XY circle parameter: X position of center / R.

Definition at line 458 of file gblsit3.py.

Referenced by gblsit3.gblSimpleHelix.getArcLengthXY(), and gblsit3.gblSimpleHelix.getPrediction().

__yRelCenter

gblsit3.gblSimpleHelix.__yRelCenter

private

XY circle parameter: Y position of center / R.

Definition at line 460 of file gblsit3.py.

Referenced by gblsit3.gblSimpleHelix.getArcLengthXY(), and gblsit3.gblSimpleHelix.getPrediction().

__z0

gblsit3.gblSimpleHelix.__z0

private

Z position at distance of closest approach.

Definition at line 456 of file gblsit3.py.

Referenced by gblsit3.gblSimpleHelix.getPrediction(), and gblsit3.gblSimpleHelix.moveTo().

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The documentation for this class was generated from the following file:

• gblsit3.py