gblsit.gblSimpleHelix Class Reference

Simple helix. More...

Inheritance diagram for gblsit.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 485 of file gblsit.py.

Constructor & Destructor Documentation

__init__()

def gblsit.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 495 of file gblsit.py.

Member Function Documentation

getArcLengthXY()

def gblsit.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 573 of file gblsit.py.

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

Referenced by gblsit.gblSimpleHelix.getPrediction().

getPrediction()

def gblsit.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 522 of file gblsit.py.

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

moveTo()

def gblsit.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 591 of file gblsit.py.

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

Member Data Documentation

__dca

gblsit.gblSimpleHelix.__dca

private

distance of closest approach in (XY)

Definition at line 503 of file gblsit.py.

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

__dir0

gblsit.gblSimpleHelix.__dir0

private

direction vector at point of closest approach (in XY)

Definition at line 501 of file gblsit.py.

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

__dzds

gblsit.gblSimpleHelix.__dzds

private

dZ/ds

Definition at line 505 of file gblsit.py.

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

__phi0

gblsit.gblSimpleHelix.__phi0

private

flight direction at point of closest approach (in XY)

Definition at line 499 of file gblsit.py.

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

__rinv

gblsit.gblSimpleHelix.__rinv

private

curvature (in XY)

Definition at line 497 of file gblsit.py.

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

__xRelCenter

gblsit.gblSimpleHelix.__xRelCenter

private

XY circle parameter: X position of center / R.

Definition at line 509 of file gblsit.py.

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

__yRelCenter

gblsit.gblSimpleHelix.__yRelCenter

private

XY circle parameter: Y position of center / R.

Definition at line 511 of file gblsit.py.

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

__z0

gblsit.gblSimpleHelix.__z0

private

Z position at distance of closest approach.

Definition at line 507 of file gblsit.py.

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

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

• gblsit.py