Sgutil - Revision history

Boiarino: Text replacement - "clonwiki.jlab.org" to "clonwiki0.jlab.org"

2015-04-17T20:10:22Z

Text replacement - "clonwiki.jlab.org" to "clonwiki0.jlab.org"

← Older revision		Revision as of 16:10, 17 April 2015
Line 27:		Line 27:
	'''ALGORITHMS DESCRIPTION'''		'''ALGORITHMS DESCRIPTION'''

	Example can be found [https://~~clonwiki~~.jlab.org/wiki/clondocs/Docs/sgutil_fig7_8.pdf here].		Example can be found [https://clonwiki0.jlab.org/wiki/clondocs/Docs/sgutil_fig7_8.pdf here].

	192-bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko, following		192-bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko, following
	[https://~~clonwiki~~.jlab.org/wiki/clondocs/Docs/sgutil_fig9.pdf adding procedure] was used to get a sum of 6 192-bit words representing 6 layers of the Drift Chamber superlayer. This method was used in ''SuperLayerSum/RemoveNoise'' procedure to found areas with segments, and in the first stage of ''SegmentSearch192'' procedure. Here is the fragment of the binary summing program:		[https://clonwiki0.jlab.org/wiki/clondocs/Docs/sgutil_fig9.pdf adding procedure] was used to get a sum of 6 192-bit words representing 6 layers of the Drift Chamber superlayer. This method was used in ''SuperLayerSum/RemoveNoise'' procedure to found areas with segments, and in the first stage of ''SegmentSearch192'' procedure. Here is the fragment of the binary summing program:

	b1 = (w0)&(w1);		b1 = (w0)&(w1);

129.57.76.91 at 14:37, 3 June 2010

2010-06-03T14:37:43Z

@@ Line 30: / Line 30: @@
 -bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko, following
-[https://clonwiki.jlab.org/wiki/clondocs/Docs/sgutil_fig9.pdf adding procedure] was used to get a sum of 6 192-bit words representing 6 layers of the Drift Chamber superlayer. This method was used in ''SuperLayerSum/RemoveNoise'' procedure to found areas with segments, and in the first stage of ''SegmentSearch192'' procedure.
+[https://clonwiki.jlab.org/wiki/clondocs/Docs/sgutil_fig9.pdf adding procedure] was used to get a sum of 6 192-bit words representing 6 layers of the Drift Chamber superlayer. This method was used in ''SuperLayerSum/RemoveNoise'' procedure to found areas with segments, and in the first stage of ''SegmentSearch192'' procedure. Here is the fragment of the binary summing program:
 ''SegmentSearch192'' searches for segments in 3 steps. On the first step shift-and-sum operation is performed separately for axial and stereo superlayers. Results are stored in 3 192-bit words, where vertical 3-bit columns contains the number

129.57.76.146 at 18:12, 2 June 2010

2010-06-02T18:12:02Z

← Older revision		Revision as of 14:12, 2 June 2010
Line 27:		Line 27:
	'''ALGORITHMS DESCRIPTION'''		'''ALGORITHMS DESCRIPTION'''

	Example can be found [https://clonwiki.jlab.org/wiki/clondocs/Docs/~~sgutil_fig8_9~~.pdf here].		Example can be found [https://clonwiki.jlab.org/wiki/clondocs/Docs/sgutil_fig7_8.pdf here].

	192-bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko, following		192-bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko, following

129.57.76.146 at 18:11, 2 June 2010

2010-06-02T18:11:31Z

← Older revision		Revision as of 14:11, 2 June 2010
Line 26:		Line 26:

	'''ALGORITHMS DESCRIPTION'''		'''ALGORITHMS DESCRIPTION'''

			Example can be found [https://clonwiki.jlab.org/wiki/clondocs/Docs/sgutil_fig8_9.pdf here].

	192-bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko, following		192-bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko, following

129.57.76.146 at 18:08, 2 June 2010

2010-06-02T18:08:59Z

← Older revision		Revision as of 14:08, 2 June 2010
Line 27:		Line 27:
	'''ALGORITHMS DESCRIPTION'''		'''ALGORITHMS DESCRIPTION'''

	192-bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko, ~~[https://clonwiki.jlab.org/wiki/clondocs/Docs/faddr000.gif simple adder] was implemented, and~~ following		192-bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko, following
	[https://clonwiki.jlab.org/wiki/clondocs/Docs/~~faddr-4b~~.~~gif~~ adding procedure] was used to get a sum of 6 192-bit words representing 6 layers of the Drift Chamber superlayer. This method was used in ''SuperLayerSum/RemoveNoise'' procedure to found areas with segments, and in the first stage of ''SegmentSearch192'' procedure.		[https://clonwiki.jlab.org/wiki/clondocs/Docs/sgutil_fig9.pdf adding procedure] was used to get a sum of 6 192-bit words representing 6 layers of the Drift Chamber superlayer. This method was used in ''SuperLayerSum/RemoveNoise'' procedure to found areas with segments, and in the first stage of ''SegmentSearch192'' procedure.

	''SegmentSearch192'' searches for segments in 3 steps. On the first step shift-and-sum operation is performed separately for axial and stereo superlayers. Results are stored in 3 192-bit words, where vertical 3-bit columns contains the number		''SegmentSearch192'' searches for segments in 3 steps. On the first step shift-and-sum operation is performed separately for axial and stereo superlayers. Results are stored in 3 192-bit words, where vertical 3-bit columns contains the number

129.57.76.146: /* NIM paper draft */

2010-06-02T15:24:54Z

NIM paper draft

← Older revision		Revision as of 11:24, 2 June 2010
Line 69:		Line 69:

	On the third step segment list is processed to select the segment with the maximum number of hits, and final list of region-based segments is created. Every segment in the list contains participated wire numbers, the slope and the shift between superlayers (latest value represents the phi angle of the track). If thresholds are reasonably high (4 and 8 for superlayer and region respectively) then the list will be short, for our example (fig.2) only one region-based segment will be reported as following: axial wire numbers are 66,66,0,0,65,65; stereo wire numbers are 70,70,0,69,0,69; slope 33; phi 17 (slope and phi are reported as an corresponding table indexes).		On the third step segment list is processed to select the segment with the maximum number of hits, and final list of region-based segments is created. Every segment in the list contains participated wire numbers, the slope and the shift between superlayers (latest value represents the phi angle of the track). If thresholds are reasonably high (4 and 8 for superlayer and region respectively) then the list will be short, for our example (fig.2) only one region-based segment will be reported as following: axial wire numbers are 66,66,0,0,65,65; stereo wire numbers are 70,70,0,69,0,69; slope 33; phi 17 (slope and phi are reported as an corresponding table indexes).

			It takes an average few hundreds of microseconds on regular PC to process segment finding for one event with the efficiency of 96-98%. To get remaining few percent thresholds must be lowered which leads to the significant increase of both the execution time and the number of segment candidates. As result following road finding procedure must deal with the huge number of combinations which increases execution time even more. In general drift chamber inefficiency was the biggest challenge for the speed of the presented approach. It was used successfully in online reconstruction where some inefficiency is allowed, however in the level 3 (software) trigger it was running in tagging mode only.

			There is a plan to use described approach in upcoming CLAS12 Trigger System as FPGA-based implementation, where in can be executed much fasted. We hope to address 'dead' wired issue and develop fast and efficient component of the Level 1 (hardware) trigger.

129.57.76.146: /* NIM paper draft */

2010-06-02T15:09:58Z

NIM paper draft

← Older revision		Revision as of 11:09, 2 June 2010
Line 68:		Line 68:
	On the second step one of the superlayers is shifted against another one, search is conducted for the region-based segments, and list of segment candidates is produced. Another threshold has been applied to the region-based segments, usually minimum 8 hits were required. Again, threshold was lowered later because of 'dead' wires to burst segment search efficiency. As soon as threshold is decreased, the length of the segment list grows significantly, and execution time come with it.		On the second step one of the superlayers is shifted against another one, search is conducted for the region-based segments, and list of segment candidates is produced. Another threshold has been applied to the region-based segments, usually minimum 8 hits were required. Again, threshold was lowered later because of 'dead' wires to burst segment search efficiency. As soon as threshold is decreased, the length of the segment list grows significantly, and execution time come with it.

	On the third step segment list is processed to select the segment with the maximum number of hits, and final list of region-based segments is created. Every segment in the list contains ~~origin~~ wire ~~number~~, slope and shift between superlayers (latest value represents the phi angle of the track).		On the third step segment list is processed to select the segment with the maximum number of hits, and final list of region-based segments is created. Every segment in the list contains participated wire numbers, the slope and the shift between superlayers (latest value represents the phi angle of the track). If thresholds are reasonably high (4 and 8 for superlayer and region respectively) then the list will be short, for our example (fig.2) only one region-based segment will be reported as following: axial wire numbers are 66,66,0,0,65,65; stereo wire numbers are 70,70,0,69,0,69; slope 33; phi 17 (slope and phi are reported as an corresponding table indexes).

129.57.76.146: /* NIM paper draft */

2010-06-02T15:03:29Z

NIM paper draft

← Older revision		Revision as of 11:03, 2 June 2010
Line 66:		Line 66:
	Segment search is conducted in 3 steps. On the first step shift-and-sum operation is performed separately for axial and stereo superlayers for the set of shift patterns representing different track segment angles from +30 to -30 degrees approximately. In our example (as it shown on fig.2) shift pattern was (0,0,1,1,1) for layers 2 through 6, which means layers 4,5 and 6 were shifted one step to the left. After every shift, 192-bit words were summed using binary numbers adding procedure as it was suggested by Pavel Degtyarenko (fig.3). Results are stored in 3 192-bit words, where vertical 3-bit columns contains the number of hits in binary format. Using 3x8 lookup tables those numbers are converted into integers stored in 192-dim arrays. Those arrays will be used on the following steps (fig.2). Only segments with the number of hits above threshold are kept. As it was found threshold equal to 4 is the best from both segment search efficiency and execution time prospectives. However because of significant number of the 'dead' wires in some areas that threshold must be set to 3, which increases significantly the number of segment candidates and execution time per event. One way to address the issue would be to convert 'dead' wires into 'hot' wires assigning hits to them permanently, but it is not the part of existing procedure.		Segment search is conducted in 3 steps. On the first step shift-and-sum operation is performed separately for axial and stereo superlayers for the set of shift patterns representing different track segment angles from +30 to -30 degrees approximately. In our example (as it shown on fig.2) shift pattern was (0,0,1,1,1) for layers 2 through 6, which means layers 4,5 and 6 were shifted one step to the left. After every shift, 192-bit words were summed using binary numbers adding procedure as it was suggested by Pavel Degtyarenko (fig.3). Results are stored in 3 192-bit words, where vertical 3-bit columns contains the number of hits in binary format. Using 3x8 lookup tables those numbers are converted into integers stored in 192-dim arrays. Those arrays will be used on the following steps (fig.2). Only segments with the number of hits above threshold are kept. As it was found threshold equal to 4 is the best from both segment search efficiency and execution time prospectives. However because of significant number of the 'dead' wires in some areas that threshold must be set to 3, which increases significantly the number of segment candidates and execution time per event. One way to address the issue would be to convert 'dead' wires into 'hot' wires assigning hits to them permanently, but it is not the part of existing procedure.

	On the second step one of the superlayers is shifted against another one, search is conducted for the region-based segments, and list of segment candidates is produced. ~~It should be mentioned~~		On the second step one of the superlayers is shifted against another one, search is conducted for the region-based segments, and list of segment candidates is produced. Another threshold has been applied to the region-based segments, usually minimum 8 hits were required. Again, threshold was lowered later because of 'dead' wires to burst segment search efficiency. As soon as threshold is decreased, the length of the segment list grows significantly, and execution time come with it.

	On the third step segment list is processed to select the segment with the maximum number of hits, and final list of segments is created.		On the third step segment list is processed to select the segment with the maximum number of hits, and final list of region-based segments is created. Every segment in the list contains origin wire number, slope and shift between superlayers (latest value represents the phi angle of the track).

129.57.76.146: /* NIM paper draft */

2010-06-02T14:51:19Z

NIM paper draft

← Older revision		Revision as of 10:51, 2 June 2010
Line 64:		Line 64:
	Noise removal is usually running first to cleanup data as much as possible. Red color hits on fig.1 will be removed at that point.		Noise removal is usually running first to cleanup data as much as possible. Red color hits on fig.1 will be removed at that point.

	Segment search is conducted in 3 steps. On the first step shift-and-sum operation is performed separately for axial and stereo superlayers for the set of shift patterns representing different track segment angles from +30 to -30 degrees approximately. In our example (as it shown on fig.2) shift pattern was (0,0,1,1,1) for layers 2 through 6, which means layers 4,5 and 6 were shifted one step to the left. After every shift, 192-bit words were summed using binary numbers adding procedure as it was suggested by Pavel Degtyarenko (fig.3). Results are stored in 3 192-bit words, where vertical 3-bit columns contains the number of hits in binary format. Using 3x8 lookup tables those numbers are converted into integers to be used on the following ~~step~~ (fig.2).		Segment search is conducted in 3 steps. On the first step shift-and-sum operation is performed separately for axial and stereo superlayers for the set of shift patterns representing different track segment angles from +30 to -30 degrees approximately. In our example (as it shown on fig.2) shift pattern was (0,0,1,1,1) for layers 2 through 6, which means layers 4,5 and 6 were shifted one step to the left. After every shift, 192-bit words were summed using binary numbers adding procedure as it was suggested by Pavel Degtyarenko (fig.3). Results are stored in 3 192-bit words, where vertical 3-bit columns contains the number of hits in binary format. Using 3x8 lookup tables those numbers are converted into integers stored in 192-dim arrays. Those arrays will be used on the following steps (fig.2). Only segments with the number of hits above threshold are kept. As it was found threshold equal to 4 is the best from both segment search efficiency and execution time prospectives. However because of significant number of the 'dead' wires in some areas that threshold must be set to 3, which increases significantly the number of segment candidates and execution time per event. One way to address the issue would be to convert 'dead' wires into 'hot' wires assigning hits to them permanently, but it is not the part of existing procedure.

	On second step one of the superlayers is shifted against another one, search is conducted for the region-based segments, and list of segment candidates is produced.		On the second step one of the superlayers is shifted against another one, search is conducted for the region-based segments, and list of segment candidates is produced. It should be mentioned

	On the third step segment list is processed to select the segment with the maximum number of hits, and final list of segments is created.		On the third step segment list is processed to select the segment with the maximum number of hits, and final list of segments is created.

129.57.76.146: /* NIM paper draft */

2010-06-02T14:40:49Z

NIM paper draft

← Older revision		Revision as of 10:40, 2 June 2010
Line 58:		Line 58:


	Described approach was used to search for the track segments~~. The segment finding process can be explained using data sample shown on fig.1. Drift chamber consists of 3 regions, each contains axial and stereo superlayers~~. Track ~~segment inside the region can be considered as straight line, so program~~ is ~~looking for the segments with the same slope in both superlayers. Such segments can be spaced few wires from each other due to~~ the ~~phi angle~~ of the ~~track,~~ which ~~creates another degree~~ of ~~freedom~~.		Described approach was used to search for the track segments. Track segments search is the first stage of the pattern recognition process (second stage is road finding) which is part of level 3 (software) trigger, as well as online event reconstruction software.

	~~Noise removing is usually running first to cleanup~~ data ~~as much as possible. Red color hits~~ on fig.1 ~~will~~ be ~~removed at that point~~.		The segment finding process can be explained using data sample shown on fig.1. Drift chamber consists of 3 regions, each contains axial and stereo superlayers. Track segment inside the region can be considered as straight line, so program is looking for the segments with the same slope in both superlayers. Segments in 2 superlayers can be spaced few wires from each other due to the phi angle of the track, which creates another degree of freedom.

	~~Segment search~~ is ~~conducted in 3 steps. On the~~ first ~~step shift-and-sum operation is performed separately for axial and stereo superlayers for the set of shift patterns representing different track segment angles from +30~~ to ~~-30 degrees approximately. In our example (~~as it shown on fig.2) shift pattern was (0,0,1,1,1) for layers 2 through 6, which means layers 4,5 and 6 were shifted one step to the left. After every shift,192-bit words were summed using binary numbers adding procedure as ~~it was suggested by Pavel Degtyarenko (fig~~.~~3). Results are stored in 3 192-bit words, where vertical 3-bit columns contains the number of~~ hits ~~in binary format. Using 3x8 lookup tables those numbers are converted into integers to be used~~ on ~~following step (~~fig.~~2).~~		Noise removal is usually running first to cleanup data as much as possible. Red color hits on fig.1 will be removed at that point.



	~~192-bit words were summed using binary numbers adding procedure. As it was suggested by Pavel Degtyarenko,~~
	~~[https://clonwiki.jlab.org/wiki/clondocs/Docs/faddr000.gif simple adder] was implemented, and following~~
	[https://clonwiki.jlab.org/wiki/clondocs/Docs/faddr-4b.gif adding procedure] was used to get a sum of 6 192-bit words representing 6 layers of the Drift Chamber superlayer. This method was used in ''SuperLayerSum/RemoveNoise'' procedure to found areas with segments, and in the first stage of ''SegmentSearch192'' procedure.

			Segment search is conducted in 3 steps. On the first step shift-and-sum operation is performed separately for axial and stereo superlayers for the set of shift patterns representing different track segment angles from +30 to -30 degrees approximately. In our example (as it shown on fig.2) shift pattern was (0,0,1,1,1) for layers 2 through 6, which means layers 4,5 and 6 were shifted one step to the left. After every shift, 192-bit words were summed using binary numbers adding procedure as it was suggested by Pavel Degtyarenko (fig.3). Results are stored in 3 192-bit words, where vertical 3-bit columns contains the number of hits in binary format. Using 3x8 lookup tables those numbers are converted into integers to be used on the following step (fig.2).

	On second step one of the superlayers is shifted against another one, search is conducted for the region-based segments, and list of segment candidates is produced.		On second step one of the superlayers is shifted against another one, search is conducted for the region-based segments, and list of segment candidates is produced.

	On the third step segment list is processed to select the segment with the maximum number of hits, and final list of segments is created.		On the third step segment list is processed to select the segment with the maximum number of hits, and final list of segments is created.