Resequence Command - Revision history

Nairnj: /* Notes */

2022-02-04T20:55:20Z

Notes

← Older revision		Revision as of 20:55, 4 February 2022
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	== Notes ==		== Notes ==

	The resequencing is done using the "GPS Algorithm, named after Gibbs, Poole, and Stockmeyer (1976).<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref> Another bandwidth minimization method is the RCM method or the Reverse Cuthill-McKee method.<ref name="RCM">E. Cuthill and J. McKee. "Reducing the bandwidth of sparse symmetric matrices," In Proc. 24th Nat. Conf. ACM, 157–172 (1969).</ref> ~~Now one~~ method gets the absolute minimum. In testing, GPS and RCM get similar results but GPS is faster.		The resequencing is done using the "GPS Algorithm, named after Gibbs, Poole, and Stockmeyer (1976).<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref> Another bandwidth minimization method is the RCM method or the Reverse Cuthill-McKee method.<ref name="RCM">E. Cuthill and J. McKee. "Reducing the bandwidth of sparse symmetric matrices," In Proc. 24th Nat. Conf. ACM, 157–172 (1969).</ref> No method gets the absolute minimum. In testing, GPS and RCM get similar results but GPS is faster.

	# It is best to start the resequencing at a node on the boundary of the object and probably on a corner. The final bandwidth may depend on the node selected for resequencing. The bandwidth is reported in FEA output results. You can vary the resequencing node to find the minimum value.		# It is best to start the resequencing at a node on the boundary of the object and probably on a corner. The final bandwidth may depend on the node selected for resequencing. The bandwidth is reported in FEA output results. You can vary the resequencing node to find the minimum value.

Nairnj: /* Notes */

2022-02-04T20:54:41Z

Notes

← Older revision		Revision as of 20:54, 4 February 2022
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	== Notes ==		== Notes ==

			The resequencing is done using the "GPS Algorithm, named after Gibbs, Poole, and Stockmeyer (1976).<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref> Another bandwidth minimization method is the RCM method or the Reverse Cuthill-McKee method.<ref name="RCM">E. Cuthill and J. McKee. "Reducing the bandwidth of sparse symmetric matrices," In Proc. 24th Nat. Conf. ACM, 157–172 (1969).</ref> Now one method gets the absolute minimum. In testing, GPS and RCM get similar results but GPS is faster.

	# It is best to start the resequencing at a node on the boundary of the object and probably on a corner. The final bandwidth may depend on the node selected for resequencing. The bandwidth is reported in FEA output results. You can vary the resequencing node to find the minimum value.		# It is best to start the resequencing at a node on the boundary of the object and probably on a corner. The final bandwidth may depend on the node selected for resequencing. The bandwidth is reported in FEA output results. You can vary the resequencing node to find the minimum value.
	# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. If you use a <tt>Resequence</tt> command on a disconnected mesh, it will detect the problem and abort the calculations.		# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. If you use a <tt>Resequence</tt> command on a disconnected mesh, it will detect the problem and abort the calculations.
	# The algorithm used to resequence the nodes in described in a paper by Gibbs, Poole, and Stockmeyer (1976).<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref>

	== References ==		== References ==
	<references/>		<references/>

Nairnj at 21:25, 2 June 2015

2015-06-02T21:25:01Z

← Older revision		Revision as of 21:25, 2 June 2015
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	where		where

	* (<tt>x</tt>, <tt>y</tt>) define the coordinates (in mm) for a point (or <tt>(R,Z)</tt> coordinates if axisymmetric). The resequencing will start at the one node nearest to that point.		* (<tt>x</tt>, <tt>y</tt>) define the coordinates (in [[ConsistentUnits Command#Legacy and Consistent Units\|length units]]) for a point (or <tt>(R,Z)</tt> coordinates if axisymmetric). The resequencing will start at the one node nearest to that point.
	* <tt>(id)</tt> is a previously defined [[Keypoint Command\|keypoint]]. The resequencing will start at the node at that keypoint.		* <tt>(id)</tt> is a previously defined [[Keypoint Command\|keypoint]]. The resequencing will start at the node at that keypoint.

Nairnj: /* Notes */

2014-01-09T17:22:04Z

Notes

← Older revision		Revision as of 17:22, 9 January 2014
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	# It is best to start the resequencing at a node on the boundary of the object and probably on a corner. The final bandwidth may depend on the node selected for resequencing. The bandwidth is reported in FEA output results. You can vary the resequencing node to find the minimum value.		# It is best to start the resequencing at a node on the boundary of the object and probably on a corner. The final bandwidth may depend on the node selected for resequencing. The bandwidth is reported in FEA output results. You can vary the resequencing node to find the minimum value.
	# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. If you use a <tt>Resequence</tt> command on a disconnected mesh, it will detect the problem and abort the calculations.		# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. If you use a <tt>Resequence</tt> command on a disconnected mesh, it will detect the problem and abort the calculations.
	# The algorithm used to resequence the nodes in described in a paper by Gibbs, Poole, and Stockmeyer.<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref>		# The algorithm used to resequence the nodes in described in a paper by Gibbs, Poole, and Stockmeyer (1976).<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref>

	== References ==		== References ==
	<references/>		<references/>

Nairnj: /* XML Input Files */

2013-09-12T06:00:27Z

XML Input Files

← Older revision		Revision as of 06:00, 12 September 2013
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	== XML Input Files ==		== XML Input Files ==

	In <tt>XML</tt> files, the two options~~, which must be the last command in the single [[FEA Boundary Conditions#XML Input Files\|<tt><GridBCs></tt> block]],~~ are:		In <tt>XML</tt> files, the two options are:

	<Resequence x='(x)' y='(y)'/>		<Resequence x='(x)' y='(y)'/>
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	<Resequence keypt='(id)'/>		<Resequence keypt='(id)'/>

	where <tt>(x)</tt>, <tt>(y)</tt>, and <tt>(id)</tt> are the same as defined [[#Scripted Input Files\|above]].		where <tt>(x)</tt>, <tt>(y)</tt>, and <tt>(id)</tt> are the same as defined [[#Scripted Input Files\|above]]. Whichever method is used, it must be the ''last'' command in the single [[FEA Boundary Conditions#XML Input Files\|<tt><GridBCs></tt> block]] in the file.

	== Notes ==		== Notes ==

Nairnj: /* XML Input Files */

2013-09-12T05:59:29Z

XML Input Files

← Older revision		Revision as of 05:59, 12 September 2013
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	== XML Input Files ==		== XML Input Files ==

	In <tt>XML</tt> files, the two options, which must be the last command in the single [[FEA Boundary Conditions#XML Input Files\|<tt><GridBCs></tt> block], are:		In <tt>XML</tt> files, the two options, which must be the last command in the single [[FEA Boundary Conditions#XML Input Files\|<tt><GridBCs></tt> block]], are:

	<Resequence x='(x)' y='(y)'/>		<Resequence x='(x)' y='(y)'/>

Nairnj: /* XML Input Files */

2013-09-12T05:59:18Z

XML Input Files

← Older revision		Revision as of 05:59, 12 September 2013
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	== XML Input Files ==		== XML Input Files ==

	In <tt>XML</tt> files, the two options, which must be ~~within~~ the <tt><GridBCs></tt> ~~element~~, are:		In <tt>XML</tt> files, the two options, which must be the last command in the single [[FEA Boundary Conditions#XML Input Files\|<tt><GridBCs></tt> block], are:

	<Resequence x='(x)' y='(y)'/>		<Resequence x='(x)' y='(y)'/>

Nairnj: /* Notes */

2013-09-11T05:44:42Z

Notes

← Older revision		Revision as of 05:44, 11 September 2013
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	# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. If you use a <tt>Resequence</tt> command on a disconnected mesh, it will detect the problem and abort the calculations.		# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. If you use a <tt>Resequence</tt> command on a disconnected mesh, it will detect the problem and abort the calculations.
	# The algorithm used to resequence the nodes in described in a paper by Gibbs, Poole, and Stockmeyer.<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref>		# The algorithm used to resequence the nodes in described in a paper by Gibbs, Poole, and Stockmeyer.<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref>
	~~# In scripted files, The <tt>Resequencing</tt> command should come after all [[FEA Input Files#Defining the FEA Mesh\|meshing commands]] are done.~~

	== References ==		== References ==
	<references/>		<references/>

Nairnj: /* Notes */

2013-09-11T05:40:57Z

Notes

← Older revision		Revision as of 05:40, 11 September 2013
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	# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. If you use a <tt>Resequence</tt> command on a disconnected mesh, it will detect the problem and abort the calculations.		# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. If you use a <tt>Resequence</tt> command on a disconnected mesh, it will detect the problem and abort the calculations.
	# The algorithm used to resequence the nodes in described in a paper by Gibbs, Poole, and Stockmeyer.<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref>		# The algorithm used to resequence the nodes in described in a paper by Gibbs, Poole, and Stockmeyer.<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref>
	# In scripted files, The <tt>Resequencing</tt> command should come after ~~the other~~ [[FEA Input Files#Defining the FEA Mesh\|meshing commands]] are done.		# In scripted files, The <tt>Resequencing</tt> command should come after all [[FEA Input Files#Defining the FEA Mesh\|meshing commands]] are done.

	== References ==		== References ==
	<references/>		<references/>

Nairnj: /* Notes */

2013-09-11T05:40:21Z

Notes

← Older revision		Revision as of 05:40, 11 September 2013
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	# It is best to start the resequencing at a node on the boundary of the object and probably on a corner. The final bandwidth may depend on the node selected for resequencing. The bandwidth is reported in FEA output results. You can vary the resequencing node to find the minimum value.		# It is best to start the resequencing at a node on the boundary of the object and probably on a corner. The final bandwidth may depend on the node selected for resequencing. The bandwidth is reported in FEA output results. You can vary the resequencing node to find the minimum value.
	# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. ~~This~~ command will ~~find such connectivity problems before~~ the calculations ~~start~~.		# Another use of this command is to verify mesh connectivity. Since disconnected sections of a static FEA mesh will cause a singular stiffness matrix, the calculations will fail. If you use a <tt>Resequence</tt> command on a disconnected mesh, it will detect the problem and abort the calculations.
	# The algorithm used to resequence the nodes in described in a paper by Gibbs, Poole, and Stockmeyer.<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref>		# The algorithm used to resequence the nodes in described in a paper by Gibbs, Poole, and Stockmeyer.<ref name='RS'>N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, "An Algorithm for Reducing the Bandwidth and Profile of a Sparse Matrix," <i>SIAM Journal of Numerical Analysis</i>, <b>13</b>, 236-250 (1976).</ref>
	# In scripted files, The <tt>Resequencing</tt> command should come after the other [[FEA Input Files#Defining the FEA Mesh\|meshing commands]] are done.		# In scripted files, The <tt>Resequencing</tt> command should come after the other [[FEA Input Files#Defining the FEA Mesh\|meshing commands]] are done.