#include <CSCCathodeLCTAnalyzer.h>

Public Member Functions
	CSCCathodeLCTAnalyzer ()

std::vector< CSCCathodeLayerInfo >	getSimInfo (const CSCCLCTDigi &clct, const CSCDetId &clctId, const CSCComparatorDigiCollection compdc, const edm::PSimHitContainer allSimHits)

double	getStripPhi (const CSCDetId &layerId, const float strip)

int	nearestHS (const std::vector< CSCCathodeLayerInfo > &allLayerInfo, double &closestPhi, double &closestEta)

void	setGeometry (const CSCGeometry *geom)

Static Public Member Functions
static void	setDebug ()

static void	setNoDebug ()

Private Member Functions
void	digiSimHitAssociator (CSCCathodeLayerInfo &info, const edm::PSimHitContainer *allSimHits)

std::vector< CSCCathodeLayerInfo >	lctDigis (const CSCCLCTDigi &clct, const CSCDetId &clctId, const CSCComparatorDigiCollection *compdc)

int	preselectDigis (const int clct_bx, const CSCDetId &layerId, const CSCComparatorDigiCollection *compdc, std::vector< CSCComparatorDigi > &digiMap, int hfstripDigis[CSCConstants::NUM_HALF_STRIPS], int time[CSCConstants::MAX_NUM_STRIPS], int comp[CSCConstants::MAX_NUM_STRIPS], int digiNum[CSCConstants::MAX_NUM_STRIPS])

Private Attributes
const CSCGeometry *	geom_

Static Private Attributes
static bool	debug = true

static bool	doME1A = false

Detailed Description

Class for Monte Carlo studies of cathode LCTs. Returns a vector of up to six (one per layer) CSCCathodeLayerInfo objects for a given CLCT. They contain the list of comparator digis used to build a given CLCT, and the list of associated (closest) SimHits.

Author: Slava Valuev 26 May 2004. Porting from ORCA by S. Valuev in September 2006.

Definition at line 25 of file CSCCathodeLCTAnalyzer.h.

Constructor & Destructor Documentation

CSCCathodeLCTAnalyzer::CSCCathodeLCTAnalyzer ( )

inline

Default constructor.

Definition at line 28 of file CSCCathodeLCTAnalyzer.h.

References relativeConstraints::geom, getSimInfo(), getStripPhi(), nearestHS(), setGeometry(), and digitizers_cfi::strip.

28 {};

Member Function Documentation

void CSCCathodeLCTAnalyzer::digiSimHitAssociator	(	CSCCathodeLayerInfo &	info,
		const edm::PSimHitContainer *	allSimHits
	)

private

Definition at line 225 of file CSCCathodeLCTAnalyzer.cc.

References CSCLayerInfo< TYPE >::addComponent(), CSCDetId::chamber(), debug, SiPixelRawToDigiRegional_cfi::deltaPhi, CSCDetId::endcap(), CSCLayerInfo< TYPE >::getId(), CSCLayerInfo< TYPE >::getRecDigis(), CSCDetId::layer(), LogDebug, LogTrace, M_PI, PSimHit::particleType(), PV3DBase< T, PVType, FrameType >::phi(), create_new_empty_test_file_cfg::prd, CSCDetId::ring(), FastTrackerRecHitCombiner_cfi::simHits, CSCDetId::station(), digitizers_cfi::strip, and GeomDet::toGlobal().

                                                                                                                  {
   // This routine matches up the closest simHit to every digi on a given layer.
   // Note that it is possible to have up to 2 digis contribute to an LCT
   // on a given layer. In a primitive algorithm used now more than one digi on
   // a layer can be associated with the same simHit.
   vector<PSimHit> simHits;
 
   vector<CSCComparatorDigi> thisLayerDigis = info.getRecDigis();
   if (!thisLayerDigis.empty()) {
     CSCDetId layerId = info.getId();
     bool me11 = (layerId.station() == 1) && (layerId.ring() == 1);
 
     // Get simHits in this layer.
     for (edm::PSimHitContainer::const_iterator simHitIt = allSimHits->begin(); simHitIt != allSimHits->end();
          simHitIt++) {
       // Find detId where simHit is located.
       CSCDetId hitId = (CSCDetId)(*simHitIt).detUnitId();
       if (hitId == layerId)
         simHits.push_back(*simHitIt);
       if (me11) {
         CSCDetId layerId_me1a(layerId.endcap(), layerId.station(), 4, layerId.chamber(), layerId.layer());
         if (hitId == layerId_me1a)
           simHits.push_back(*simHitIt);
       }
     }
 
     if (!simHits.empty()) {
       ostringstream strstrm;
       if (debug) {
         strstrm << "\nLayer " << layerId.layer() << " has " << simHits.size() << " SimHit(s); phi value(s) = ";
       }
 
       // Get the strip number for every digi and convert to phi.
       for (vector<CSCComparatorDigi>::iterator prd = thisLayerDigis.begin(); prd != thisLayerDigis.end(); prd++) {
         double deltaPhiMin = 999.;
         double bestHitPhi = 999.;
         PSimHit* bestHit = nullptr;
 
         int strip = prd->getStrip();
         double digiPhi = getStripPhi(layerId, strip - 0.5);
 
         const CSCLayer* csclayer = geom_->layer(layerId);
         for (vector<PSimHit>::iterator psh = simHits.begin(); psh != simHits.end(); psh++) {
           // Get the local phi for the simHit.
           LocalPoint hitLP = psh->localPosition();
           GlobalPoint hitGP = csclayer->toGlobal(hitLP);
           double hitPhi = hitGP.phi();
           if (debug)
             strstrm << hitPhi << " ";
           // Find the lowest deltaPhi and store the associated simHit.
           // Check to see if comparison is on pi border, and if so, make
           // corrections.
           double deltaPhi = 999.;
           if (fabs(hitPhi - digiPhi) < M_PI) {
             deltaPhi = fabs(hitPhi - digiPhi);
           } else {
             if (debug)
               LogDebug("digiSimHitAssociator") << "SimHit and Digi are close to edge!!!";
             deltaPhi = fabs(fabs(hitPhi - digiPhi) - 2. * M_PI);
           }
           if (deltaPhi < deltaPhiMin) {
             deltaPhiMin = deltaPhi;
             bestHit = &(*psh);
             bestHitPhi = hitPhi;
           }
         }
         if (debug) {
           strstrm << "\nDigi Phi: " << digiPhi << ", closest SimHit phi: " << bestHitPhi
                   << ", particle type: " << bestHit->particleType();
         }
         info.addComponent(*bestHit);
       }
       if (debug) {
         LogTrace("digiSimHitAssociator") << strstrm.str();
       }
     }
   }
 }

vector< CSCCathodeLayerInfo > CSCCathodeLCTAnalyzer::getSimInfo	(	const CSCCLCTDigi &	clct,
		const CSCDetId &	clctId,
		const CSCComparatorDigiCollection *	compdc,
		const edm::PSimHitContainer *	allSimHits
	)

Constructs vector of CSCCathodeLayerInfo objects for CLCT.

Definition at line 16 of file CSCCathodeLCTAnalyzer.cc.

References Exception, and CSCConstants::NUM_LAYERS.

Referenced by CSCTriggerPrimitivesReader::calcResolution(), and CSCCathodeLCTAnalyzer().

                                                                                                      {
   // Fills vector of CSCCathodeLayerInfo objects.  There can be up to 6 such
   // objects (one per layer); they contain the list of comparator digis used to
   // build a given CLCT, and the list of associated (closest) SimHits.
   // Filling is done in two steps: first, we construct the list of comparator
   // digis; next, find associated SimHits.
   vector<CSCCathodeLayerInfo> clctInfo = lctDigis(clct, clctId, compdc);
 
   // Sanity checks.
   if (clctInfo.size() > CSCConstants::NUM_LAYERS) {
     throw cms::Exception("CSCCathodeLCTAnalyzer") << "+++ Number of CSCCathodeLayerInfo objects, " << clctInfo.size()
                                                   << ", exceeds max expected, " << CSCConstants::NUM_LAYERS << " +++\n";
   }
   //  not a good check for high PU
   //if (clctInfo.size() != (unsigned)clct.getQuality()) {
   //  edm::LogWarning("L1CSCTPEmulatorWrongValues")
   //    << "+++ Warning: mismatch between CLCT quality, " << clct.getQuality()
   //    << ", and the number of layers with digis, " << clctInfo.size()
   //    << ", in clctInfo! +++\n";
   //}
 
   // Find the closest SimHit to each Digi.
   vector<CSCCathodeLayerInfo>::iterator pcli;
   for (pcli = clctInfo.begin(); pcli != clctInfo.end(); pcli++) {
     digiSimHitAssociator(*pcli, allSimHits);
   }
 
   return clctInfo;
 }

double CSCCathodeLCTAnalyzer::getStripPhi	(	const CSCDetId &	layerId,
		const float	strip
	)

Returns phi position of a given strip.

Definition at line 401 of file CSCCathodeLCTAnalyzer.cc.

References CSCLayer::geometry(), OffsetRadialStripTopology::localPosition(), CSCConstants::MAX_NUM_STRIPS, PV3DBase< T, PVType, FrameType >::phi(), GeomDet::toGlobal(), and CSCLayerGeometry::topology().

Referenced by CSCTriggerPrimitivesReader::calcResolution(), and CSCCathodeLCTAnalyzer().

                                                                                     {
   // Returns phi position of a given strip.
   if (strip < 0. || strip >= CSCConstants::MAX_NUM_STRIPS) {
     edm::LogWarning("L1CSCTPEmulatorWrongInput")
         << "+++ Warning: strip, " << strip << ", is not in [0-" << CSCConstants::MAX_NUM_STRIPS << ") interval +++\n";
   }
 
   const CSCLayer* csclayer = geom_->layer(layerId);
   const CSCLayerGeometry* layerGeom = csclayer->geometry();
 
   // Position at the center of the strip.
   LocalPoint digiLP = layerGeom->topology()->localPosition(strip);
   // The alternative calculation gives exactly the same answer.
   // double ystrip = 0.0;
   // double xstrip = topology->xOfStrip(strip, ystrip);
   // LocalPoint  digiLP = LocalPoint(xstrip, ystrip);
   GlobalPoint digiGP = csclayer->toGlobal(digiLP);
   double phi = digiGP.phi();
 
   return phi;
 }

vector< CSCCathodeLayerInfo > CSCCathodeLCTAnalyzer::lctDigis	(	const CSCCLCTDigi &	clct,
		const CSCDetId &	clctId,
		const CSCComparatorDigiCollection *	compdc
	)

private

Definition at line 49 of file CSCCathodeLCTAnalyzer.cc.

References CSCLayerInfo< TYPE >::addComponent(), CSCDetId::chamber(), CSCPatternBank::clct_pattern, CSCPatternBank::clct_pattern_offset, CSCLayerInfo< TYPE >::clear(), AlCaHLTBitMon_QueryRunRegistry::comp, debug, CSCDetId::endcap(), CSCCLCTDigi::getBX(), CSCLayerInfo< TYPE >::getId(), CSCCLCTDigi::getKeyStrip(), CSCCLCTDigi::getPattern(), CSCCLCTDigi::getStripType(), CSCDetId::layer(), LogDebug, LogTrace, CSCConstants::MAX_HALFSTRIPS_IN_PATTERN, CSCConstants::MAX_NUM_STRIPS, CSCConstants::NUM_HALF_STRIPS, CSCConstants::NUM_LAYERS, CSCDetId::ring(), CSCLayerInfo< TYPE >::setId(), CSCDetId::station(), digitizers_cfi::strip, and ntuplemaker::time.

                                                                                                        {
   // Function to find a list of ComparatorDigis used to create an LCT.
   // The list of ComparatorDigis is stored in a class called CSCLayerInfo which
   // contains the layerId's of the stored ComparatorDigis as well as the actual
   // digis themselves.
   int hfstripDigis[CSCConstants::NUM_HALF_STRIPS];
   int time[CSCConstants::MAX_NUM_STRIPS], comp[CSCConstants::MAX_NUM_STRIPS];
   int digiNum[CSCConstants::MAX_NUM_STRIPS];
   int digiId = -999;
   CSCCathodeLayerInfo tempInfo;
   vector<CSCCathodeLayerInfo> vectInfo;
 
   // Inquire the clct for its key half-strip, strip type and pattern number.
   int clct_keystrip = clct.getKeyStrip();
   int clct_stripType = clct.getStripType();
   int clct_pattern = clct.getPattern();
   int clct_bx = clct.getBX();
 
   // Re-scale the key di-strip number to the count used in the search.
   if (clct_stripType == 0)
     clct_keystrip /= 4;
 
   if (debug) {
     char stype = (clct_stripType == 0) ? 'D' : 'H';
     LogDebug("lctDigis") << "\nlctDigis: CLCT keystrip = " << clct_keystrip << " (" << stype << ")"
                          << " pattern = " << clct_pattern << "; Id:"
                          << " endcap " << clctId.endcap() << ", station " << clctId.station() << ", ring "
                          << clctId.ring() << ", chamber " << clctId.chamber();
   }
 
   // 'Staggering' for key layer.  Needed for TMB07 version.
   const int key_layer = 3;  // counting from 1.
   CSCDetId layerId(clctId.endcap(), clctId.station(), clctId.ring(), clctId.chamber(), key_layer);
   const CSCLayer* csclayer = geom_->layer(layerId);
   int key_stagger = (csclayer->geometry()->stagger() + 1) / 2;
 
   for (int i_layer = 0; i_layer < CSCConstants::NUM_LAYERS; i_layer++) {
     // Clear tempInfo values every iteration before using.
     tempInfo.clear();
 
     // @ Switch to maps eventually
     vector<CSCComparatorDigi> digiMap;
     int digi_num = 0;
     for (int i_hstrip = 0; i_hstrip < CSCConstants::NUM_HALF_STRIPS; i_hstrip++) {
       hfstripDigis[i_hstrip] = -999;
     }
     for (int i_strip = 0; i_strip < CSCConstants::MAX_NUM_STRIPS; i_strip++) {
       time[i_strip] = -999;
       comp[i_strip] = 0;
       digiNum[i_strip] = -999;
     }
 
     // CLCTs belong to a chamber, so their layerId is 0.  Comparator digis
     // belong to layers, so in order to access them we need to add layer
     // number to CLCT's endcap, chamber, etc.
     CSCDetId layerId(clctId.endcap(), clctId.station(), clctId.ring(), clctId.chamber(), i_layer + 1);
 
     // Preselection of Digis: right layer and bx.
     digi_num += preselectDigis(clct_bx, layerId, compdc, digiMap, hfstripDigis, time, comp, digiNum);
 
     // In case of ME1/1, one can also look for digis in ME1/A.
     // Skip them for now since the resolution of CLCTs in ME1/A is
     // terrible (strips are ganged; channel numbers translated to be
     // in CFEB=4).
     if (doME1A) {
       if (clctId.station() == 1 && clctId.ring() == 1) {
         CSCDetId layerId_me1a(clctId.endcap(), clctId.station(), 4, clctId.chamber(), i_layer + 1);
         digi_num += preselectDigis(clct_bx, layerId_me1a, compdc, digiMap, hfstripDigis, time, comp, digiNum);
       }
     }
 
     // Loop over all the strips in a pattern.
     int max_pattern_strips, layer, strip;
     max_pattern_strips = CSCConstants::MAX_HALFSTRIPS_IN_PATTERN;
     for (int i_strip = 0; i_strip < max_pattern_strips; i_strip++) {
       layer = CSCPatternBank::clct_pattern[clct_pattern][i_strip];
       if (layer == i_layer) {
         strip = clct_keystrip + key_stagger + CSCPatternBank::clct_pattern_offset[i_strip];
         if (strip >= 0 && strip < CSCConstants::NUM_HALF_STRIPS) {
           digiId = hfstripDigis[strip];
           // halfstripDigis contains the digi numbers
           // that were carried through the different transformations
           // to keystrip. -999 means there was no Digi.
           if (digiId >= 0) {
             tempInfo.setId(layerId);                 // store the layer of this object
             tempInfo.addComponent(digiMap[digiId]);  // and the RecDigi
             if (debug)
               LogTrace("lctDigis") << " Digi on CLCT: strip/comp/time " << digiMap[digiId];
           }
         }
       }
     }
 
     // Save results for each non-empty layer.
     if (tempInfo.getId().layer() != 0) {
       vectInfo.push_back(tempInfo);
     }
   }
   return vectInfo;
 }

int CSCCathodeLCTAnalyzer::nearestHS	(	const std::vector< CSCCathodeLayerInfo > &	allLayerInfo,
		double &	closestPhi,
		double &	closestEta
	)

Finds half-strip, phi and eta of the nearest SimHit for comparison to the reconstructed values.

Definition at line 304 of file CSCCathodeLCTAnalyzer.cc.

References AlCaHLTBitMon_QueryRunRegistry::comp, debug, relativeConstraints::empty, PV3DBase< T, PVType, FrameType >::eta(), CSCLayer::geometry(), mps_fire::i, CSCConstants::KEY_CLCT_LAYER, CSCDetId::layer(), PSimHit::localPosition(), LogDebug, M_PI, CSCConstants::MAX_NUM_STRIPS, PV3DBase< T, PVType, FrameType >::phi(), digitizers_cfi::strip, OffsetRadialStripTopology::strip(), GeomDet::toGlobal(), and CSCLayerGeometry::topology().

Referenced by CSCTriggerPrimitivesReader::calcResolution(), and CSCCathodeLCTAnalyzer().

                                                          {
   // Function to set the simulated values for comparison to the reconstructed.
   // It first tries to look for the SimHit in the key layer.  If it is
   // unsuccessful, it loops over all layers and looks for an associated
   // hit in any one of the layers.  First instance of a hit gives a calculation
   // for phi.
   int nearestHS = -999;
   PSimHit matchedHit;
   bool hit_found = false;
   CSCDetId layerId;
   static const int key_layer = CSCConstants::KEY_CLCT_LAYER;
 
   vector<CSCCathodeLayerInfo>::const_iterator pli;
   for (pli = allLayerInfo.begin(); pli != allLayerInfo.end(); pli++) {
     if (pli->getId().layer() == key_layer) {
       vector<PSimHit> thisLayerHits = pli->getSimHits();
       if (!thisLayerHits.empty()) {
         // There can be one RecDigi (and therefore only one SimHit)
         // in a keylayer.
         if (thisLayerHits.size() != 1) {
           edm::LogWarning("L1CSCTPEmulatorWrongValues")
               << "+++ Warning: " << thisLayerHits.size() << " SimHits in key layer " << key_layer << "! +++ \n";
           for (unsigned i = 0; i < thisLayerHits.size(); i++) {
             edm::LogWarning("L1CSCTPEmulatorWrongValues") << " SimHit # " << i << thisLayerHits[i] << "\n";
           }
         }
         matchedHit = thisLayerHits[0];
         layerId = pli->getId();
         hit_found = true;
         break;
       }
     }
   }
 
   if (hit_found == false) {
     for (pli = allLayerInfo.begin(); pli != allLayerInfo.end(); pli++) {
       // if there is any occurrence of simHit size greater that zero, use this.
       if (!(pli->getRecDigis()).empty() && !(pli->getSimHits()).empty()) {
         // Always use the first SimHit for now.
         matchedHit = (pli->getSimHits())[0];
         layerId = pli->getId();
         hit_found = true;
         break;
       }
     }
   }
 
   // Set phi and eta if there were any hits found.
   if (hit_found) {
     const CSCLayer* csclayer = geom_->layer(layerId);
     const CSCLayerGeometry* layerGeom = csclayer->geometry();
     //nearestStrip = layerGeom->nearestStrip(matchedHit.localPosition());
     // Float in units of the strip (angular) width.  From RadialStripTopology
     // comments: "Strip in which a given LocalPoint lies. This is a float
     // which represents the fractional strip position within the detector.
     // Returns zero if the LocalPoint falls at the extreme low edge of the
     // detector or BELOW, and float(nstrips) if it falls at the extreme high
     // edge or ABOVE."
     float strip = layerGeom->topology()->strip(matchedHit.localPosition());
 
     // Should be in the interval [0-MAX_STRIPS).  I see (rarely) cases when
     // strip = nearestStrip = MAX_STRIPS; do not know how to handle them.
     int nearestStrip = static_cast<int>(strip);
     if (nearestStrip < 0 || nearestStrip >= CSCConstants::MAX_NUM_STRIPS) {
       edm::LogWarning("L1CSCTPEmulatorWrongInput")
           << "+++ Warning: nearest strip, " << nearestStrip << ", is not in [0-" << CSCConstants::MAX_NUM_STRIPS
           << ") interval; strip = " << strip << " +++\n";
     }
     // Left/right half of the strip.
     int comp = ((strip - nearestStrip) < 0.5) ? 0 : 1;
     nearestHS = 2 * nearestStrip + comp;
 
     GlobalPoint thisPoint = csclayer->toGlobal(matchedHit.localPosition());
     closestPhi = thisPoint.phi();
     closestEta = thisPoint.eta();
     ostringstream strstrm;
     if (debug)
       strstrm << "Matched cathode phi: " << closestPhi;
     if (closestPhi < 0.) {
       closestPhi += 2. * M_PI;
       if (debug)
         strstrm << "(" << closestPhi << ")";
     }
     if (debug) {
       strstrm << " eta: " << closestEta << " on a layer " << layerId.layer() << " (1-6);"
               << " nearest strip: " << nearestStrip;
       LogDebug("nearestHS") << strstrm.str();
     }
   }
 
   return nearestHS;
 }

int CSCCathodeLCTAnalyzer::preselectDigis	(	const int	clct_bx,
		const CSCDetId &	layerId,
		const CSCComparatorDigiCollection *	compdc,
		std::vector< CSCComparatorDigi > &	digiMap,
		int	hfstripDigis[CSCConstants::NUM_HALF_STRIPS],
		int	time[CSCConstants::MAX_NUM_STRIPS],
		int	comp[CSCConstants::MAX_NUM_STRIPS],
		int	digiNum[CSCConstants::MAX_NUM_STRIPS]
	)

private

Definition at line 152 of file CSCCathodeLCTAnalyzer.cc.

References AlCaHLTBitMon_QueryRunRegistry::comp, debug, CSCLayer::geometry(), CSCDetId::layer(), LogDebug, CSCDetId::ring(), CSCLayerGeometry::stagger(), CSCDetId::station(), and ntuplemaker::time.

                                                                                    {
   // Preselection of Digis: right layer and bx.
   int digi_num = 0;
 
   // Parameters defining time window for accepting hits; should come from
   // configuration file eventually.
   const int fifo_tbins = 12;
   const int hit_persist = 4;
   const int drift_delay = 2;
 
   // 'Staggering' for this layer.
   const CSCLayer* csclayer = geom_->layer(layerId);
   int stagger = (csclayer->geometry()->stagger() + 1) / 2;
 
   bool me1a = (layerId.station() == 1) && (layerId.ring() == 4);
 
   const CSCComparatorDigiCollection::Range rcompd = compdc->get(layerId);
   for (CSCComparatorDigiCollection::const_iterator digiIt = rcompd.first; digiIt != rcompd.second; ++digiIt) {
     if (debug)
       LogDebug("lctDigis") << "Comparator digi: layer " << layerId.layer() - 1
                            << " strip/comparator/time =" << (*digiIt);
 
     if ((*digiIt).getComparator() == 0 || (*digiIt).getComparator() == 1) {
       int bx_time = (*digiIt).getTimeBin();
       if (bx_time >= 0 && bx_time < fifo_tbins) {
         // Do not use digis which could not have contributed to a given CLCT.
         int latch_bx = clct_bx + drift_delay;
         if (bx_time <= latch_bx - hit_persist || bx_time > latch_bx) {
           if (debug)
             LogDebug("lctDigis") << "Late comparator digi: layer " << layerId.layer() - 1
                                  << " strip/comparator/time =" << (*digiIt) << " skipping...";
           continue;
         }
 
         // If there is more than one digi on the same strip, pick the one
         // which occurred earlier.
         int i_strip = (*digiIt).getStrip() - 1;  // starting from 0
         if (me1a && i_strip < 16) {
           // Move ME1/A comparators from CFEB=0 to CFEB=4 if this has not
           // been done already.
           i_strip += 64;
         }
 
         if (time[i_strip] <= 0 || time[i_strip] > bx_time) {
           // @ Switch to maps; check for match in time.
           int i_hfstrip = 2 * i_strip + (*digiIt).getComparator() + stagger;
           hfstripDigis[i_hfstrip] = digi_num;
 
           // Arrays for distrip stagger
           comp[i_strip] = (*digiIt).getComparator();
           time[i_strip] = bx_time;
           digiNum[i_strip] = digi_num;
 
           if (debug)
             LogDebug("lctDigis") << "digi_num = " << digi_num << " half-strip = " << i_hfstrip
                                  << " strip = " << i_strip;
         }
       }
     }
     digiMap.push_back(*digiIt);
     digi_num++;
   }
 
   return digi_num;
 }