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#include <RecoLocalTracker/SiPixelClusterizer/interface/PixelThresholdClusterizer.h>
A specific threshold-based pixel clustering algorithm.
A threshold-based clustering algorithm which clusters SiPixelDigis into SiPixelClusters for each DetUnit. The algorithm is straightforward and purely topological: the clustering process starts with seed pixels and continues by adding adjacent pixels above the pixel threshold. Once the cluster is made, it has to be above the cluster threshold as well.
The clusterization is performed on a matrix with size equal to the size of the pixel detector, each cell containing the ADC count of the corresponding pixel. The matrix is reset after each clusterization.
The search starts from seed pixels, i.e. pixels with sufficiently large amplitudes, found at the time of filling of the matrix and stored in a
At this point the noise and dead channels are ignored, but soon they won't be.
SiPixelCluster contains a barrycenter, but it should be noted that that information is largely useless. One must use a PositionEstimator class to compute the RecHit position and its error for every given cluster.
Sets the PixelArrayBuffer dimensions and pixel thresholds. Makes clusters and stores them in theCache if the option useCache has been set.
General logic of PixelThresholdClusterizer:
The clusterization is performed on a matrix with size equal to the size of the pixel detector, each cell containing the ADC count of the corresponding pixel. The matrix is reset after each clusterization.
The search starts from seed pixels, i.e. pixels with sufficiently large amplitudes, found at the time of filling of the matrix and stored in a SiPixelArrayBuffer.
Translate the pixel charge to electrons, we are suppose to do the calibrations ADC->electrons here. Modify the thresholds to be in electrons, convert adc to electrons. d.k. 20/3/06 Get rid of the noiseVector. d.k. 28/3/06
Definition at line 59 of file PixelThresholdClusterizer.h.
| PixelThresholdClusterizer::PixelThresholdClusterizer | ( | edm::ParameterSet const & | conf | ) |
Constructor: Initilize the buffer to hold pixels from a detector module.
This is a vector of 44k ints, stays valid all the time.
Definition at line 43 of file PixelThresholdClusterizer.cc.
00043 : 00044 conf_(conf), bufferAlreadySet(false), theNumOfRows(0), theNumOfCols(0), detid_(0) { 00045 00046 // Get thresholds in electrons 00047 thePixelThreshold = 00048 conf_.getParameter<int>("ChannelThreshold"); 00049 theSeedThreshold = 00050 conf_.getParameter<int>("SeedThreshold"); 00051 theClusterThreshold = 00052 conf_.getParameter<double>("ClusterThreshold"); 00053 theConversionFactor = 00054 conf_.getParameter<int>("VCaltoElectronGain"); 00055 theOffset = 00056 conf_.getParameter<int>("VCaltoElectronOffset"); 00057 00058 00059 // Get the constants for the miss-calibration studies 00060 doMissCalibrate=conf_.getUntrackedParameter<bool>("MissCalibrate",true); 00061 00062 theBuffer.setSize( theNumOfRows, theNumOfCols ); 00063 //initTiming(); 00064 }
| PixelThresholdClusterizer::~PixelThresholdClusterizer | ( | ) |
Definition at line 184 of file PixelThresholdClusterizer.cc.
References detid_, doMissCalibrate, SiPixelGainCalibrationServiceBase::getGain(), SiPixelGainCalibrationServiceBase::getPedestal(), int, SiPixelGainCalibrationServiceBase::isDead(), pedestal, theConversionFactor, theOffset, and PixelClusterizerBase::theSiPixelGainCalibrationService_.
Referenced by copy_to_buffer().
00184 { 00185 int electrons = 0; 00186 00187 if(doMissCalibrate) { 00188 // do not perform calibration if pixel is dead! 00189 00190 if(!theSiPixelGainCalibrationService_->isDead(detid_,col,row)){ 00191 00192 // Linear approximation of the TANH response 00193 // Pixel(0,0,0) 00194 //const float gain = 2.95; // 1 ADC = 2.95 VCALs (1/0.339) 00195 //const float pedestal = -83.; // -28/0.339 00196 // Roc-0 average 00197 //const float gain = 1./0.357; // 1 ADC = 2.80 VCALs 00198 //const float pedestal = -28.2 * gain; // -79. 00199 00200 float DBgain = theSiPixelGainCalibrationService_->getGain(detid_, col, row); 00201 float DBpedestal = theSiPixelGainCalibrationService_->getPedestal(detid_, col, row) * DBgain; 00202 00203 00204 // Roc-6 average 00205 //const float gain = 1./0.313; // 1 ADC = 3.19 VCALs 00206 //const float pedestal = -6.2 * gain; // -19.8 00207 // 00208 float vcal = adc * DBgain - DBpedestal; 00209 00210 // atanh calibration 00211 // Roc-6 average 00212 //const float p0 = 0.00492; 00213 //const float p1 = 1.998; 00214 //const float p2 = 90.6; 00215 //const float p3 = 134.1; 00216 // Roc-6 average 00217 //const float p0 = 0.00382; 00218 //const float p1 = 0.886; 00219 //const float p2 = 112.7; 00220 //const float p3 = 113.0; 00221 //float vcal = ( atanh( (adc-p3)/p2) + p1)/p0; 00222 00223 electrons = int( vcal * theConversionFactor + theOffset); 00224 } 00225 } 00226 else { // No misscalibration in the digitizer 00227 // Simple (default) linear gain 00228 const float gain = 135.; // 1 ADC = 135 electrons 00229 const float pedestal = 0.; // 00230 electrons = int(adc * gain + pedestal); 00231 } 00232 00233 return electrons; 00234 }
| void PixelThresholdClusterizer::clear_buffer | ( | DigiIterator | begin, | |
| DigiIterator | end | |||
| ) | [private] |
Clear the internal buffer array.
Pixels which are not part of recognized clusters are NOT ERASED during the cluster finding. Erase them now.
TO DO: ask Danek... wouldn't it be faster to simply memcopy() zeros into the whole buffer array?
Definition at line 156 of file PixelThresholdClusterizer.cc.
References SiPixelArrayBuffer::set_adc(), and theBuffer.
Referenced by clusterizeDetUnit().
00156 { 00157 // TimeMe tm1( *theClearTimer, false); 00158 for(DigiIterator di = begin; di != end; ++di ) { 00159 theBuffer.set_adc( di->row(), di->column(), 0 ); // reset pixel adc to 0 00160 } 00161 }
| void PixelThresholdClusterizer::clusterizeDetUnit | ( | const edm::DetSet< PixelDigi > & | input, | |
| const PixelGeomDetUnit * | pixDet, | |||
| const std::vector< short > & | badChannels, | |||
| edmNew::DetSetVector< SiPixelCluster >::FastFiller & | output | |||
| ) | [virtual] |
Cluster pixels.
This method operates on a matrix of pixels and finds the largest contiguous cluster around each seed pixel. Input and output data stored in DetSet
Implements PixelClusterizerBase.
Definition at line 101 of file PixelThresholdClusterizer.cc.
References edm::DetSet< T >::begin(), begin, SiPixelCluster::charge(), clear_buffer(), copy_to_buffer(), edm::DetSet< T >::detId(), detid_, edm::DetSet< T >::end(), end, i, make_cluster(), edmNew::DetSetVector< T >::push_back(), setup(), theBuffer, theClusterThreshold, and theSeeds.
00104 { 00105 00106 //TimeMe tm1( *theClustersTimer, false); 00107 00108 DigiIterator begin = input.begin(); 00109 DigiIterator end = input.end(); 00110 00111 // Do not bother for empty detectors 00112 //if (begin == end) cout << " PixelThresholdClusterizer::clusterizeDetUnit - No digis to clusterize"; 00113 00114 // Set up the clusterization on this DetId. 00115 if (!setup(pixDet)) return; 00116 detid_ = input.detId(); 00117 // Copy PixelDigis to the buffer array; select the seed pixels 00118 // on the way, and store them in theSeeds. 00119 copy_to_buffer(begin, end); 00120 // At this point we know the number of seeds on this DetUnit, and thus 00121 // also the maximal number of possible clusters, so resize theClusters 00122 // in order to make vector<>::push_back() efficient. 00123 // output.reserve ( theSeeds.size() ); //GPetruc: It is better *not* to reserve, with the new DetSetVector! 00124 00125 // Loop over all seeds. TO DO: wouldn't using iterators be faster? 00126 for (unsigned int i = 0; i < theSeeds.size(); i++) { 00127 00128 if ( theBuffer(theSeeds[i]) != 0) { // Is this seed still valid? 00129 00130 // Make a cluster around this seed 00131 SiPixelCluster cluster = make_cluster( theSeeds[i] ); 00132 00133 // Check if the cluster is above threshold 00134 // (TO DO: one is signed, other unsigned, gcc warns...) 00135 if ( cluster.charge() >= theClusterThreshold ) { 00136 output.push_back( cluster ); 00137 } 00138 } 00139 } 00140 // Erase the seeds. 00141 theSeeds.clear(); 00142 00143 // Need to clean unused pixels from the buffer array. 00144 clear_buffer(begin, end); 00145 00146 }
| void PixelThresholdClusterizer::copy_to_buffer | ( | DigiIterator | begin, | |
| DigiIterator | end | |||
| ) | [private] |
Copy adc counts from PixelDigis into the buffer, identify seeds.
Definition at line 166 of file PixelThresholdClusterizer.cc.
References ecalMGPA::adc(), calibrate(), parsecf::pyparsing::col(), row, SiPixelArrayBuffer::set_adc(), theBuffer, thePixelThreshold, theSeeds, and theSeedThreshold.
Referenced by clusterizeDetUnit().
00166 { 00167 //TimeMe tm1( *theCopyTimer, false); 00168 for(DigiIterator di = begin; di != end; ++di) { 00169 int row = di->row(); 00170 int col = di->column(); 00171 int adc = calibrate(di->adc(),col,row); // convert ADC -> electrons 00172 if ( adc >= thePixelThreshold) { 00173 theBuffer.set_adc( row, col, adc); 00174 if ( adc >= theSeedThreshold) { 00175 theSeeds.push_back( SiPixelCluster::PixelPos(row,col) ); 00176 } 00177 } 00178 } 00179 }
| SiPixelCluster PixelThresholdClusterizer::make_cluster | ( | const SiPixelCluster::PixelPos & | pix | ) | [private] |
The actual clustering algorithm: group the neighboring pixels around the seed.
Definition at line 239 of file PixelThresholdClusterizer.cc.
References SiPixelCluster::add(), c, SiPixelCluster::PixelPos::col(), r, SiPixelCluster::PixelPos::row(), SiPixelArrayBuffer::set_adc(), theBuffer, and thePixelThreshold.
Referenced by clusterizeDetUnit().
00240 { 00241 //TimeMe tm1( *theMakeClustTimer, false); 00242 00243 // Make the cluster 00244 SiPixelCluster cluster( pix, theBuffer( pix.row(), pix.col()) ); 00245 stack<SiPixelCluster::PixelPos, vector<SiPixelCluster::PixelPos> > pixel_stack; 00246 00247 theBuffer.set_adc( pix, 0); 00248 pixel_stack.push( pix); 00249 00250 while ( ! pixel_stack.empty()) { 00251 SiPixelCluster::PixelPos curpix = pixel_stack.top(); pixel_stack.pop(); 00252 for ( int r = curpix.row()-1; r <= curpix.row()+1; ++r) { 00253 for ( int c = curpix.col()-1; c <= curpix.col()+1; ++c) { 00254 if ( theBuffer(r,c) >= thePixelThreshold) { 00255 SiPixelCluster::PixelPos newpix(r,c); 00256 cluster.add( newpix, theBuffer(r,c)); 00257 theBuffer.set_adc( newpix, 0); 00258 pixel_stack.push( newpix); 00259 00260 } 00261 } 00262 } 00263 } 00264 return cluster; 00265 }
| bool PixelThresholdClusterizer::setup | ( | const PixelGeomDetUnit * | pixDet | ) | [private] |
Private helper methods:.
Prepare the Clusterizer to work on a particular DetUnit.
Re-init the size of the panel/plaquette (so update nrows and ncols),
Definition at line 72 of file PixelThresholdClusterizer.cc.
References bufferAlreadySet, PixelTopology::ncolumns(), PixelTopology::nrows(), SiPixelArrayBuffer::setSize(), PixelGeomDetUnit::specificTopology(), theBuffer, theNumOfCols, and theNumOfRows.
Referenced by clusterizeDetUnit().
00072 { 00073 00074 // Cache the topology. 00075 const PixelTopology & topol = pixDet->specificTopology(); 00076 00077 // Get the new sizes. 00078 int nrows = topol.nrows(); // rows in x 00079 int ncols = topol.ncolumns(); // cols in y 00080 00081 if( nrows > theNumOfRows || ncols > theNumOfCols ) { // change only when a larger is needed 00082 //if( nrows != theNumOfRows || ncols != theNumOfCols ) { 00083 //cout << " PixelThresholdClusterizer: pixel buffer redefined to " 00084 // << nrows << " * " << ncols << endl; 00085 theNumOfRows = nrows; // Set new sizes 00086 theNumOfCols = ncols; 00087 // Resize the buffer 00088 theBuffer.setSize(nrows,ncols); // Modify 00089 bufferAlreadySet = true; 00090 } 00091 00092 return true; 00093 }
Definition at line 74 of file PixelThresholdClusterizer.h.
uint32_t PixelThresholdClusterizer::detid_ [private] |
Definition at line 96 of file PixelThresholdClusterizer.h.
Referenced by calibrate(), and clusterizeDetUnit().
Data storage.
Definition at line 77 of file PixelThresholdClusterizer.h.
Referenced by clear_buffer(), clusterizeDetUnit(), copy_to_buffer(), make_cluster(), and setup().
std::vector<SiPixelCluster> PixelThresholdClusterizer::theClusters [private] |
Definition at line 80 of file PixelThresholdClusterizer.h.
float PixelThresholdClusterizer::theClusterThreshold [private] |
float PixelThresholdClusterizer::theClusterThresholdInNoiseUnits [private] |
Definition at line 85 of file PixelThresholdClusterizer.h.
int PixelThresholdClusterizer::theNumOfCols [private] |
int PixelThresholdClusterizer::theNumOfRows [private] |
Geometry-related information.
Definition at line 94 of file PixelThresholdClusterizer.h.
Referenced by setup().
int PixelThresholdClusterizer::theOffset [private] |
Definition at line 87 of file PixelThresholdClusterizer.h.
Referenced by copy_to_buffer(), and make_cluster().
float PixelThresholdClusterizer::thePixelThresholdInNoiseUnits [private] |
std::vector<SiPixelCluster::PixelPos> PixelThresholdClusterizer::theSeeds [private] |
Definition at line 79 of file PixelThresholdClusterizer.h.
Referenced by clusterizeDetUnit(), and copy_to_buffer().
float PixelThresholdClusterizer::theSeedThresholdInNoiseUnits [private] |
Definition at line 84 of file PixelThresholdClusterizer.h.
1.5.4