Lilian | 11/17/04 | Clusters with the same starting strip | StSsdPointMaker | The cluster splitting in StSsdwafer.cc seems to gives wrong results in the case of large clusters. In the following example, the cluster 0 is splitted in 3 clusters having the same first strip (433).
------------------------------>List of strips
id,sig,noise : 433 9 3.5
id,sig,noise : 434 7 2.9375
id,sig,noise : 435 7 2.875
id,sig,noise : 436 9 2.9375
id,sig,noise : 437 7 2.9375
id,sig,noise : 438 9 2.875
id,sig,noise : 439 7 2.625
id,sig,noise : 440 7 2.6875
id,sig,noise : 441 9 3.0625
id,sig,noise : 442 6 2.75
id,sig,noise : 443 7 2.9375
------------------------------>Clusterisation done
N,Size,FirstStrip,StripMean,TotAdc,FirstAdc,LastAdc,TotNoise : 9 11 433 437.857 84 9 7 24
------------------------------>Splitting done
N,Size,FirstStrip,StripMean,TotAdc,FirstAdc,LastAdc,TotNoise : 28 2 433 433.438 16 9 7 5
N,Size,FirstStrip,StripMean,TotAdc,FirstAdc,LastAdc,TotNoise : 29 5 433 434.714 35 9 3 10
N,Size,FirstStrip,StripMean,TotAdc,FirstAdc,LastAdc,TotNoise : 30 7 433 435.964 55 9 7 15
N,Size,FirstStrip,StripMean,TotAdc,FirstAdc,LastAdc,TotNoise : 31 11 433 437.857 84 9 7 24
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Due to a bug in the StSsdClusterList::splitCluster method. Within the loop over the maxima found in the cluster,
the following line
// localFirstStrip = CurrentCluster->getFirstStrip();
was reseting the current FirstStrip to the initial first strip of the big cluster. When commented, the result look like this :
------------------------------>Splitting done
N,Size,FirstStrip,StripMean,TotAdc,FirstAdc,LastAdc,TotNoise : 28 2 433 433.438 16 9 7 5
N,Size,FirstStrip,StripMean,TotAdc,FirstAdc,LastAdc,TotNoise : 29 3 435 435.789 19 7 3 5
N,Size,FirstStrip,StripMean,TotAdc,FirstAdc,LastAdc,TotNoise : 30 3 437 438 23 7 7 6
N,Size,FirstStrip,StripMean,TotAdc,FirstAdc,LastAdc,TotNoise : 31 4 440 441.448 29 7 7 9
<------------------------------
There is still something to look at since the signal (7 adc counts) on strip 437 is shared by the clusters 29 (3 adc counts) and the cluster 30 (7 adc counts) which gives a total signal bigger that the original.
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