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ClusterFit.cxx

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// $Id: ClusterFit.cxx,v 1.6 2000/12/07 20:10:01 burnett Exp $


#include "reconstruction/ClusterFit.h"

//#include "instrument/SiTracker.h"

#include <cmath>

static int number_of_trays = 19;
static int xNum = 4, yNum=4;
static double  si_strip_pitch   = 0.020848214285714;

ClusterFit::ClusterFit (HitMap *Pos)
  :        LSQFit()
{

    // Inputs: 
    //          HitMap Pos - map of coordinates using the ModId and Plane #
    //
    // Computes the LSQ fit using the hits contained in Pos
    //  First finds all clusters of hits - within one strip pitch of each other in a plane
    //  Then computes the LSQ fit of all the hits in clusters.
    
    const int num_conv = number_of_trays-1;
    numHitsUsed = 0; // initialize 
    float strip_pitch = si_strip_pitch;
    // loop thru all towers and planes and hits
    int modID, iplane;
    HitMap cluster;
    unsigned int min_cluster_size = 6; //SiTracker::siMinCluster(); not updating instrument
    const int maxModId = (xNum * yNum) - 1;

    for (modID = 0; modID <= maxModId; modID++) {
        for (iplane = 0; iplane < num_conv; iplane++) {
            // find a cluster of min_cluster_size or more within one plane
            bool flag=false;
            float lastHit, lastZ = 99999.99f; // make sure it gets reset
            int index = modID*1000+iplane;
            for(HitMap::const_iterator it = Pos[index].begin(); it != Pos[index].end(); it++){
                if(!flag) {
                    lastHit = (*it).first;
                    lastZ = (*it).second;
                    flag = true;
                    continue;   // just pick up the first hit in this plane and go get the 2nd
                }
                float xP = (*it).first;
                float zP = (*it).second;

                if ( abs(lastHit - xP) <= strip_pitch ) {
                    cluster[lastHit] = lastZ;
                } else {  // No cluster OR we need to load the current cluster and delete the map
                    if (cluster.size() >= min_cluster_size) {
                        for(HitMap::const_iterator it = cluster.begin(); it != cluster.end(); it++){
                            // Change weights based on cluster size?
                            addData((*it).first, (*it).second, 1/(strip_pitch*strip_pitch));
                            ++numHitsUsed;
                        }
                    }
                    cluster.clear();
                } // end if
                lastHit = xP;
                lastZ = zP;
            }  // end for
        }  // end for
    }  // end for

    doFit();  // call LSQfit
}

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