examples reworked

git-svn-id: http://svnsrv.desy.de/public/GeneralBrokenLines/trunk@141 281f6f2b-e318-4fd1-8bce-1a4ba7aab212

cpp/examples/example1.cpp

@@ -28,52 +28,12 @@
  */
 
 #include <time.h>
-#include "example1.h"
+#include "exampleUtil.h"
 #include "GblTrajectory.h"
 
 using namespace gbl;
 using namespace Eigen;
 
-Matrix5d gblSimpleJacobian(double ds, double cosl, double bfac) {
-	/// Simple jacobian: quadratic in arc length difference
-	/**
-	 * \param [in] ds    (3D) arc-length
-	 * \param [in] cosl  cos(lambda)
-	 * \param [in] bfac  Bz*c
-	 * \return jacobian
-	 */
-	Matrix5d jac;
-	jac.setIdentity();
-	jac(1, 0) = -bfac * ds * cosl;
-	jac(3, 0) = -0.5 * bfac * ds * ds * cosl;
-	jac(3, 1) = ds;
-	jac(4, 2) = ds;
-	return jac;
-}
-
-double unrm() {
-	///  unit normal distribution, Box-Muller method, polar form
-	static double unrm2 = 0.0;
-	static bool cached = false;
-	if (!cached) {
-		double x, y, r;
-		do {
-			x = 2.0 * rand() / RAND_MAX - 1;
-			y = 2.0 * rand() / RAND_MAX - 1;
-			r = x * x + y * y;
-		} while (r == 0.0 || r > 1.0);
-		// (x,y) in unit circle
-		double d = sqrt(-2.0 * log(r) / r);
-		double unrm1 = x * d;
-		unrm2 = y * d;
-		cached = true;
-		return unrm1;
-	} else {
-		cached = false;
-		return unrm2;
-	}
-}
-
 void example1() {
 	/// Simple technical example (curvilinear as local system).
 	/**

cpp/examples/example2.cpp

@@ -28,52 +28,12 @@
  */
 
 #include <time.h>
-#include "example1.h"
+#include "exampleUtil.h"
 #include "GblTrajectory.h"
 
 using namespace gbl;
 using namespace Eigen;
 
-Matrix5d gblSimpleJacobian2(double ds, double cosl, double bfac) {
-	/// Simple jacobian: quadratic in arc length difference
-	/**
-	 * \param [in] ds    (3D) arc-length
-	 * \param [in] cosl  cos(lambda)
-	 * \param [in] bfac  Bz*c
-	 * \return jacobian
-	 */
-	Matrix5d jac;
-	jac.setIdentity();
-	jac(1, 0) = -bfac * ds * cosl;
-	jac(3, 0) = -0.5 * bfac * ds * ds * cosl;
-	jac(3, 1) = ds;
-	jac(4, 2) = ds;
-	return jac;
-}
-
-double unrm2() {
-	///  unit normal distribution, Box-Muller method, polar form
-	static double unrm2 = 0.0;
-	static bool cached = false;
-	if (!cached) {
-		double x, y, r;
-		do {
-			x = 2.0 * rand() / RAND_MAX - 1;
-			y = 2.0 * rand() / RAND_MAX - 1;
-			r = x * x + y * y;
-		} while (r == 0.0 || r > 1.0);
-		// (x,y) in unit circle
-		double d = sqrt(-2.0 * log(r) / r);
-		double unrm1 = x * d;
-		unrm2 = y * d;
-		cached = true;
-		return unrm1;
-	} else {
-		cached = false;
-		return unrm2;
-	}
-}
-
 void example2() {
 	/// Simple technical example (measurement as local system).
 	/**
@@ -151,7 +111,7 @@ void example2() {
 	for (unsigned int iTry = 1; iTry <= nTry; ++iTry) {
 		// curvilinear track parameters
 		for (unsigned int i = 0; i < 5; ++i) {
-			clPar[i] = clErr[i] * unrm2();
+			clPar[i] = clErr[i] * unrm();
 		}
 //		std::cout << " Try " << iTry << ":" << clPar << std::endl;
 		Matrix2d addDer;
@@ -197,7 +157,7 @@ void example2() {
 			// measurement - prediction in measurement system with error
 			Vector2d meas = proL2m * clPar.tail(2);
 			for (unsigned int i = 0; i < 2; ++i) {
-				meas[i] += measErr[i] * unrm2();
+				meas[i] += measErr[i] * unrm();
 			}
 			pointMeas.addMeasurement(meas, measPrec);
 
@@ -205,7 +165,7 @@ void example2() {
 			listOfPoints.push_back(pointMeas);
 
 // propagate to scatterer
-			jacPointToPoint = gblSimpleJacobian2(step, cosLambda, bfac);
+			jacPointToPoint = gblSimpleJacobian(step, cosLambda, bfac);
 			clPar = jacPointToPoint * clPar;
 			s += step;
 			if (iLayer < nLayer - 1) {
@@ -223,7 +183,7 @@ void example2() {
 				listOfPoints.push_back(pointScat);
 				// scatter a little
 				for (unsigned int i = 0; i < 2; ++i) {
-					clPar[i + 1] += scatErr[i] * unrm2();
+					clPar[i + 1] += scatErr[i] * unrm();
 				}
 				// propagate to next measurement layer
 				clPar = jacPointToPoint * clPar;

cpp/examples/example3.cpp

@@ -28,52 +28,12 @@
  */
 
 #include <time.h>
-#include "example1.h"
+#include "exampleUtil.h"
 #include "GblTrajectory.h"
 
 using namespace gbl;
 using namespace Eigen;
 
-Matrix5d gblSimpleJacobian3(double ds, double cosl, double bfac) {
-	/// Simple jacobian: quadratic in arc length difference
-	/**
-	 * \param [in] ds    (3D) arc-length
-	 * \param [in] cosl  cos(lambda)
-	 * \param [in] bfac  Bz*c
-	 * \return jacobian
-	 */
-	Matrix5d jac;
-	jac.setIdentity();
-	jac(1, 0) = -bfac * ds * cosl;
-	jac(3, 0) = -0.5 * bfac * ds * ds * cosl;
-	jac(3, 1) = ds;
-	jac(4, 2) = ds;
-	return jac;
-}
-
-double unrm3() {
-	///  unit normal distribution, Box-Muller method, polar form
-	static double unrm2 = 0.0;
-	static bool cached = false;
-	if (!cached) {
-		double x, y, r;
-		do {
-			x = 2.0 * rand() / RAND_MAX - 1;
-			y = 2.0 * rand() / RAND_MAX - 1;
-			r = x * x + y * y;
-		} while (r == 0.0 || r > 1.0);
-		// (x,y) in unit circle
-		double d = sqrt(-2.0 * log(r) / r);
-		double unrm1 = x * d;
-		unrm2 = y * d;
-		cached = true;
-		return unrm1;
-	} else {
-		cached = false;
-		return unrm2;
-	}
-}
-
 void example3() {
 	/// Simple technical example (measure scattering).
 	/**
@@ -156,7 +116,7 @@ void example3() {
 	for (unsigned int iTry = 1; iTry <= nTry; ++iTry) {
 		// curvilinear track parameters
 		for (unsigned int i = 0; i < 5; ++i) {
-			clPar[i] = clErr[i] * unrm3();
+			clPar[i] = clErr[i] * unrm();
 		}
 		clCov.setZero();
 		for (unsigned int i = 0; i < 5; ++i) {
@@ -192,7 +152,7 @@ void example3() {
 			// measurement - prediction in measurement system with error
 			Vector2d meas = proL2m * clPar.tail(2);
 			for (unsigned int i = 0; i < 2; ++i) {
-				meas[i] += measErr[i] * unrm3();
+				meas[i] += measErr[i] * unrm();
 			}
 			pointMeas.addMeasurement(proL2m, meas, measPrec);
 			/* point with (correlated) measurements (in local system)
@@ -220,7 +180,7 @@ void example3() {
 				clSeed = clCov.inverse();
 			}
 // propagate to scatterer
-			jacPointToPoint = gblSimpleJacobian3(step, cosLambda, bfac);
+			jacPointToPoint = gblSimpleJacobian(step, cosLambda, bfac);
 			clPar = jacPointToPoint * clPar;
 			clCov = jacPointToPoint * clCov * jacPointToPoint.adjoint();
 			s += step;
@@ -241,7 +201,7 @@ void example3() {
 				}
 				// scatter a little
 				for (unsigned int i = 0; i < 2; ++i) {
-					clPar[i + 1] += scatErr[i] * unrm3();
+					clPar[i + 1] += scatErr[i] * unrm();
 					clCov(i + 1, i + 1) += scatErr[i] * scatErr[i];
 				}
 				// propagate to next measurement layer

cpp/examples/exampleDc.cpp

+/*
+ * exampleDc.cpp
+ *
+ *  Created on: 6 Nov 2018
+ *      Author: kleinwrt
+ */
+
+/** \file
+ *  Example drift chamber application.
+ *
+ *  \author Claus Kleinwort, DESY, 2018 (Claus.Kleinwort@desy.de)
+ *
+ *  \copyright
+ *  Copyright (c) 2018 Deutsches Elektronen-Synchroton,
+ *  Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY \n\n
+ *  This library is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU Library General Public License as
+ *  published by the Free Software Foundation; either version 2 of the
+ *  License, or (at your option) any later version. \n\n
+ *  This library 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 Library General Public License for more details. \n\n
+ *  You should have received a copy of the GNU Library General Public
+ *  License along with this program (see the file COPYING.LIB for more
+ *  details); if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <time.h>
+#include "exampleDc.h"
+#include "GblTrajectory.h"
+
+using namespace gbl;
+using namespace Eigen;
+
+/// Drift chamber example
+/**
+ * Simulate and reconstruct helical tracks in a sector of (forward) drift chambers.
+ *
+ *  Create points on initial trajectory, create trajectory from points,
+ *  fit and write trajectory to MP-II binary file (for rigid body alignment).
+ *
+ *  Setup:
+ *   - Beam forward (+Z) direction
+ *   - Constant magnetic field in Z direction
+ *   - Planar drift chambers with normal in XZ plane, center at Y=0, 1D measurement from (azimuthal) wires, cell size 2 cm.
+ *   - Multiple scattering in detectors (gas, wires, walls) (air in between ignored)
+ *   - Curvilinear system (T,U,V) as local coordinate system and (q/p, slopes, offsets) as local track parameters
+ *
+ * \remark To exercise (mis)alignment different sets of layers (with different geometry)
+ * for simulation and reconstruction can be used.
+ *
+ * Example steering file for Millepede-II (B=0, chamber alignment):
+ * \code{.unparsed}
+ * Cfiles
+ * milleBinaryISN.dat
+ *
+ * method inversion 3 0.1
+ * chiscut 30. 6.
+ * printcounts
+ * ! fix first chamber as reference
+ * parameter
+ * 1001  0.  -1.
+ * 1002  0.  -1.
+ * 1003  0.  -1.
+ * 1004  0.  -1.
+ * 1005  0.  -1.
+ * 1006  0.  -1.
+ * end
+ * \endcode
+ */
+void exampleDc() {
+
+	// detector layers (ordered in Z):
+	// name, position (x,y,z), thickness (X/X_0), xz-angle, stereo-angle, resolution
+	double thickness[12];
+	thickness[0] = 0.0025; // gas, wire, wall
+	for (unsigned int iLayer = 1; iLayer < 11; ++iLayer)
+		thickness[iLayer] = 0.0005; // gas, wire
+	thickness[11] = 0.0025; // gas, wire, wall
+	// list of layers
+	std::vector<GblDetectorLayer> layers;
+	const double theta(25.), cosTheta(cos(theta / 180. * M_PI)), sinTheta(
+			sin(theta / 180. * M_PI));
+	// 1. chamber at distance of 200 cm
+	double dist = 200.;
+	for (unsigned int iLayer = 0; iLayer < 6; ++iLayer) {
+		layers.push_back(
+				CreateLayerDc("CH1+", dist * sinTheta, 0.0, dist * cosTheta,
+						thickness[iLayer], theta, 6., 0.030)); // +6 deg stereo layers
+		dist += 2.;
+	}
+	for (unsigned int iLayer = 6; iLayer < 12; ++iLayer) {
+		layers.push_back(
+				CreateLayerDc("CH1-", dist * sinTheta, 0.0, dist * cosTheta,
+						thickness[iLayer], theta, -6., 0.030)); // -6 deg stereo layers
+		dist += 2.;
+	}
+	// 2. chamber at distance of 300 cm
+	dist = 300.;
+	for (unsigned int iLayer = 0; iLayer < 6; ++iLayer) {
+		layers.push_back(
+				CreateLayerDc("CH2+", dist * sinTheta, 0.0, dist * cosTheta,
+						thickness[iLayer], theta, 6., 0.030)); // +6 deg stereo layers
+		dist += 2.;
+	}
+	for (unsigned int iLayer = 6; iLayer < 12; ++iLayer) {
+		layers.push_back(
+				CreateLayerDc("CH2-", dist * sinTheta, 0.0, dist * cosTheta,
+						thickness[iLayer], theta, -6., 0.030)); // -6 deg stereo layers
+		dist += 2.;
+	}
+	// 3. chamber at distance of 400 cm
+	dist = 400.;
+	for (unsigned int iLayer = 0; iLayer < 6; ++iLayer) {
+		layers.push_back(
+				CreateLayerDc("CH3+", dist * sinTheta, 0.0, dist * cosTheta,
+						thickness[iLayer], theta, 6., 0.030)); // +6 deg stereo layers
+		dist += 2.;
+	}
+	for (unsigned int iLayer = 6; iLayer < 12; ++iLayer) {
+		layers.push_back(
+				CreateLayerDc("CH3-", dist * sinTheta, 0.0, dist * cosTheta,
+						thickness[iLayer], theta, -6., 0.030)); // -6 deg stereo layers
+		dist += 2.;
+	}
+
+	/* print layers
+	 for (unsigned int iLayer = 0; iLayer < layers.size(); ++iLayer) {
+	 layers[iLayer].print();
+	 } */
+
+	unsigned int nTry = 10000; //: number of tries
+	std::cout << " GblDc $Rev$ " << nTry << ", " << layers.size()
+			<< std::endl;
+	srand(4711);
+	clock_t startTime = clock();
+
+	double qbyp = 0.2; // 5 GeV
+	// const double bfac = 0.003;  // B*c for 1 T
+	const double bfac = 0.;  // B*c for 0 T
+
+	MilleBinary mille; // for producing MillePede-II binary file
+
+	double Chi2Sum = 0.;
+	int NdfSum = 0;
+	double LostSum = 0.;
+	int numFit = 0;
+
+	for (unsigned int iTry = 0; iTry < nTry; ++iTry) {
+
+		// helix parameter for track generation
+		const double genDca = 0.1 * unrm(); // normal
+		const double genZ0 = 0.1 * unrm(); // normal
+		const double genPhi0 = 0.52 * (2. * unif() - 1.); // uniform, [-30..30] deg
+		const double genDzds = 10. * unif() + 1.2; // uniform, lambda ~ [50..85] deg
+		const double genCurv = bfac * qbyp * sqrt(1. + genDzds * genDzds);
+
+		//
+		// generate hits
+		//
+		std::vector<Vector2d> hits;
+		double curv(genCurv), phi0(genPhi0), dca(genDca), dzds(genDzds), z0(
+				genZ0);
+		const double cosLambda = 1. / sqrt(1. + dzds * dzds);
+		for (unsigned int iLayer = 0; iLayer < layers.size(); ++iLayer) {
+			// local constant (Bfield) helix
+			GblSimpleHelix hlx = GblSimpleHelix(curv, phi0, dca, dzds, z0);
+			// prediction from local helix
+			GblHelixPrediction pred = layers[iLayer].intersectWithHelix(hlx);
+			// std::cout << " layer " << iLayer << " arc-length " << pred.getArcLength() << std::endl;
+			Vector2d meas = pred.getMeasPred();
+			// smear according to resolution
+			Vector2d sigma = layers[iLayer].getResolution();
+			meas[0] += sigma[0] * unrm();
+			meas[1] += sigma[1] * unrm();
+			// save hit
+			hits.push_back(meas);
+			// scatter at intersection point
+			Vector3d measPos = pred.getPosition();
+			double radlen = layers[iLayer].getRadiationLength()
+					/ fabs(pred.getCosIncidence());
+			double errMs = gblMultipleScatteringError(qbyp, radlen); // simple model
+			// move to intersection point
+			hlx.moveToXY(measPos[0], measPos[1], phi0, dca, z0); // update phi0, dca, z0
+			phi0 += unrm() * errMs / cosLambda;		       // scattering for phi
+			dzds += unrm() * errMs / (cosLambda * cosLambda); // scattering for dzds
+			GblSimpleHelix newhlx = GblSimpleHelix(curv, phi0, dca, dzds, z0); // after scattering
+			// move back
+			newhlx.moveToXY(-measPos[0], -measPos[1], phi0, dca, z0); // update phi0, dca, z0
+		}
+
+		//
+		// fit track with GBL
+		//
+		// seed (with true parameters)
+		double seedCurv(genCurv), seedPhi0(genPhi0), seedDca(genDca), seedDzds(
+				genDzds), seedZ0(genZ0);
+		GblSimpleHelix seed = GblSimpleHelix(seedCurv, seedPhi0, seedDca,
+				seedDzds, seedZ0);
+		// (previous) arc-length
+		double sOld = 0.;
+		const double cosLambdaSeed = 1. / sqrt(1. + (seedDzds * seedDzds));
+		// list of points on trajectory
+		std::vector<GblPoint> listOfPoints;
+		for (unsigned int iLayer = 0; iLayer < layers.size(); ++iLayer) {
+			// std::cout << " hit " << iLayer << " " << hits[iLayer].transpose() << std::endl;
+			GblDetectorLayer& layer = layers[iLayer];
+			// prediction from seeding helix
+			GblHelixPrediction pred = layer.intersectWithHelix(seed);
+			double sArc = pred.getArcLength();	// arc-length
+			Vector2d measPrediction = pred.getMeasPred(); // measurement prediction
+			Vector2d measPrecision = layer.getPrecision(); // measurement precision
+			// residuals
+			Vector2d res(hits[iLayer][0] - measPrediction[0],
+					hits[iLayer][1] - measPrediction[1]);
+			// transformation global system to local (curvilinear) (u,v) (matrix from row vectors)
+			Matrix<double, 2, 3> transG2l = pred.getCurvilinearDirs();
+			// transformation measurement system to global system
+			Matrix3d transM2g = layer.getMeasSystemDirs().inverse();
+			// projection matrix (measurement plane to local (u,v))
+			Matrix2d proM2l = transG2l * transM2g.block<3, 2>(0, 0);// skip measurement normal
+			// projection matrix (local (u,v) to measurement plane)
+			Matrix2d proL2m = proM2l.inverse();
+			// propagation
+			Matrix5d jacPointToPoint = gblSimpleJacobian(
+					(sArc - sOld) / cosLambdaSeed, cosLambdaSeed, bfac);
+			sOld = sArc;
+			// point with (independent) measurements (in measurement system)
+			GblPoint point(jacPointToPoint);
+			point.addMeasurement(proL2m, res, measPrecision);
+			// global labels and parameters for rigid body alignment
+			std::vector<int> labGlobal(6);
+			Vector3d pos = pred.getPosition();
+			Vector3d dir = pred.getDirection();
+			/* Layer alignment in local (measurement) system
+			 for (int p = 0; p < 6; p++)
+			 labGlobal[p] = (iLayer + 1) * 10 + p + 1;
+			 Matrix<double, 2, 6> derGlobal = layer.getRigidBodyDerLocal(pos,
+			 dir); */
+			// Chamber alignment in global system (as common system for both stereo orientations)
+			for (int p = 0; p < 6; p++)
+				labGlobal[p] = (iLayer / 12 + 1) * 1000 + p + 1;// chamber alignment
+			Matrix<double, 2, 6> derGlobal = layer.getRigidBodyDerGlobal(pos,
+					dir).block<2, 6>(0, 0);
+			point.addGlobals(labGlobal, derGlobal);
+			// add scatterer to point
+			double radlen = layer.getRadiationLength()
+					/ fabs(pred.getCosIncidence());
+			double errMs = gblMultipleScatteringError(qbyp, radlen);// simple model
+			if (errMs > 0.) {
+				Vector2d scat(0., 0.);
+				Vector2d scatPrec(1. / (errMs * errMs), 1. / (errMs * errMs)); // scattering precision matrix is diagonal in curvilinear system
+				point.addScatterer(scat, scatPrec);
+			}
+			// add point to trajectory
+			listOfPoints.push_back(point);
+		}
+		// create trajectory
+		GblTrajectory traj(listOfPoints, bfac != 0.);
+		// fit trajectory
+		double Chi2;
+		int Ndf;
+		double lostWeight;
+		unsigned int ierr = traj.fit(Chi2, Ndf, lostWeight);
+		//std::cout << " Fit " << iTry << ": "<< Chi2 << ", " << Ndf << ", " << lostWeight << std::endl;
+		// successfully fitted?
+		if (!ierr) {
+			// write to MP binary file
+			traj.milleOut(mille);
+			// update statistics
+			Chi2Sum += Chi2;
+			NdfSum += Ndf;
+			LostSum += lostWeight;
+			numFit++;
+		}
+	}
+	clock_t endTime = clock();
+	double diff = endTime - startTime;
+	double cps = CLOCKS_PER_SEC;
+	std::cout << " Time elapsed " << diff / cps << " s" << std::endl;
+	std::cout << " Chi2/Ndf = " << Chi2Sum / NdfSum << std::endl;
+	std::cout << " Tracks fitted " << numFit << std::endl;
+}
+
+namespace gbl {
+
+/// Create a drift chamber layer with 1D measurement.
+/**
+ * Create drift chamber layer with 1D measurement (u)
+ * \param [in] aName       name
+ * \param [in] xPos        X-position (of center)
+ * \param [in] yPos        Y-position (of center)
+ * \param [in] zPos        Z-position (of center)
+ * \param [in] thickness   thickness / radiation_length
+ * \param [in] xzAngle     angle of normal in XZ plane
+ * \param [in] stereoAngle stereo angle
+ * \param [in] uRes        resolution in u-direction
+ */
+GblDetectorLayer CreateLayerDc(const std::string aName, double xPos,
+		double yPos, double zPos, double thickness, double xzAngle,
+		double stereoAngle, double uRes) {
+	Vector3d aCenter(xPos, yPos, zPos);
+	Vector2d aResolution(uRes, 0.);
+	Vector2d aPrecision(1. / (uRes * uRes), 0.);
+	Matrix3d measTrafo;
+	const double cosXz = cos(xzAngle / 180. * M_PI);
+	const double sinXz = sin(xzAngle / 180. * M_PI);
+	const double cosSt = cos(stereoAngle / 180. * M_PI);
+	const double sinSt = sin(stereoAngle / 180. * M_PI);
+	measTrafo << cosSt * cosXz, sinSt, -cosSt * sinXz, -sinSt * cosXz, cosSt, sinSt
+			* sinXz, sinXz, 0., cosXz; // U,V,N
+	Matrix3d alignTrafo;
+	alignTrafo << cosXz, 0., -sinXz, 0., 1., 0., sinXz, 0., cosXz; // I,J,K
+	return GblDetectorLayer(aName, 1, thickness, aCenter, aResolution,
+			aPrecision, measTrafo, alignTrafo);
+}
+
+}

cpp/examples/exampleDc.h

+/*
+ * exampleDc.h
+ *
+ *  Created on: 6 Nov 2018
+ *      Author: kleinwrt
+ */
+
+/** \file
+ *  Definitions for exampleDc.
+ *
+ *  \author Claus Kleinwort, DESY, 2018 (Claus.Kleinwort@desy.de)
+ *
+ *  \copyright
+ *  Copyright (c) 2018 Deutsches Elektronen-Synchroton,
+ *  Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY \n\n
+ *  This library is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU Library General Public License as
+ *  published by the Free Software Foundation; either version 2 of the
+ *  License, or (at your option) any later version. \n\n
+ *  This library 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 Library General Public License for more details. \n\n
+ *  You should have received a copy of the GNU Library General Public
+ *  License along with this program (see the file COPYING.LIB for more
+ *  details); if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef SRC_EXAMPLEDC_H_
+#define SRC_EXAMPLEDC_H_
+
+#include "exampleUtil.h"
+
+//! Namespace for the general broken lines package
+namespace gbl {
+
+GblDetectorLayer CreateLayerDc(const std::string aName, double xPos,
+		double yPos, double zPos, double thickness, double xzAngle,
+		double stereoAngle, double uRes);
+
+}
+
+#endif /* SRC_EXAMPLEDC_H_ */

cpp/examples/exampleSit.cpp

@@ -45,46 +45,71 @@ using namespace Eigen;
  *   - Beam (mainly) in X direction
  *   - Constant magnetic field in Z direction
  *   - Silicon sensors measuring in YZ plane, orthogonal (pixel) or non-orthogonal (stereo strips) measurement systems
- *   - Multiple scattering in sensors (air inbetween ignored)
+ *   - Multiple scattering in sensors (air in between ignored)
  *   - Curvilinear system (T,U,V) as local coordinate system and (q/p, slopes, offsets) as local track parameters
  *
  * \remark To exercise (mis)alignment different sets of layers (with different geometry)
  * for simulation and reconstruction can be used.
+ *
+ * Example steering file for Millepede-II (B=0):