IDA/Analysis - Revision history

Jpye at 00:45, 22 March 2015

2015-03-22T00:45:47Z

← Older revision		Revision as of 00:45, 22 March 2015
Line 2:		Line 2:

	# '''<tt>reanalyze_solver_lists</tt>''', to update the rels/vars in the system system according to the WHENs		# '''<tt>reanalyze_solver_lists</tt>''', to update the rels/vars in the system system according to the WHENs
	# set the ~~'nonbasic'~~ flag to zero ~~for all~~ normal variables~~, and to~~ one ~~for~~ the independent variable ('x')		# set the <tt>VAR_NONBASIC</tt> flag: zero = 'normal' variables; one = the independent variable ('x')
	# '''<tt>integrator_ida_check_vars</tt>''', to check for differential variables that are not incident (for example when 'Q' is not present in any equation except in the form of 'der(Q)': we want to expand the solvers_var_list in that case to include Q, so that IDA can pass values of Q back to the user. Does this function do anything else?		# '''<tt>integrator_ida_check_vars</tt>''', to check for differential variables that are not incident (for example when 'Q' is not present in any equation except in the form of 'der(Q)': we want to expand the solvers_var_list in that case to include Q, so that IDA can pass values of Q back to the user. Does this function do anything else?
	# '''<tt>integrator_ida_flag_rels</tt>''', simply loops through all of the relations in the solvers_rel_list, and calls <tt>rel_classify_differential</tt>, which checks if any of the variables in a relation are derivatives, ie like 'der(x)'.		# '''<tt>integrator_ida_flag_rels</tt>''', simply loops through all of the relations in the solvers_rel_list, and calls <tt>rel_classify_differential</tt>, which checks if any of the variables in a relation are derivatives, ie like 'der(x)'.

Jpye at 13:32, 21 March 2015

2015-03-21T13:32:15Z

← Older revision		Revision as of 13:32, 21 March 2015
Line 3:		Line 3:
	# '''<tt>reanalyze_solver_lists</tt>''', to update the rels/vars in the system system according to the WHENs		# '''<tt>reanalyze_solver_lists</tt>''', to update the rels/vars in the system system according to the WHENs
	# set the 'nonbasic' flag to zero for all normal variables, and to one for the independent variable ('x')		# set the 'nonbasic' flag to zero for all normal variables, and to one for the independent variable ('x')
	# '''<tt>integrator_ida_check_vars</tt>''', to check for differential variables that are not incident~~, downgrading~~ '~~differential~~' ~~variables to algebraic variables if no derivative~~ is present, ~~and marking any..~~.		# '''<tt>integrator_ida_check_vars</tt>''', to check for differential variables that are not incident (for example when 'Q' is not present in any equation except in the form of 'der(Q)': we want to expand the solvers_var_list in that case to include Q, so that IDA can pass values of Q back to the user. Does this function do anything else?
	# '''<tt>integrator_ida_flag_rels</tt>'''		# '''<tt>integrator_ida_flag_rels</tt>''', simply loops through all of the relations in the solvers_rel_list, and calls <tt>rel_classify_differential</tt>, which checks if any of the variables in a relation are derivatives, ie like 'der(x)'.
	# '''<tt>integrator_ida_sort_rels_and_vars</tt>'''		# '''<tt>integrator_ida_sort_rels_and_vars</tt>'''. For vars, this cuts the 'nonderivs' first, then the 'derivs' and then the 'others' (including fixed variables and the independent variable). For rels, this cuts the active, included, equality relations to the start of the list. TODO: we're not checking whether or not the model includes inequalities?
	# '''<tt>integrator_ida_create_lists</tt>'''		# '''<tt>integrator_ida_create_lists</tt>'''. Creates lists y, ydot and y_id, which help IDA to find its way back to the correct entries in the solvers_var_list.
	# '''<tt>integrator_ida_check_diffindex</tt>''' (performs a series of ''hopefully unnecessary'' checks)		# '''<tt>integrator_ida_check_diffindex</tt>''' (performs a series of ''hopefully unnecessary'' checks)
	# (there is some code commented out here to do with checking the structure of the system for structural singularity etc)		# (there is some code commented out here to do with checking the structure of the system for structural singularity etc)
	# '''<tt>integrator_ida_check_index</tt>''' should tell the user if there is an index problem (perhaps we can apply automatic index reduction?)		# '''<tt>integrator_ida_check_index</tt>''' should tell the user if there is an index problem (perhaps we can apply automatic index reduction?). This is done by calculating the jacobian matrices df_dydp and dg_dya (using system_jacobian function that was written for IDA), checking both are square, and checking that both of them are full rank. TODO: check if this is being done every time we cross a boundary?
	# some checks of the diffvars: do we have a single indep var, is the indep var what we expected it to be.		# some checks of the diffvars: do we have a single indep var, is the indep var what we expected it to be. TODO it seems like it's too late to be checking this here?
	# copy the list of observed vars (both continuous and discrete) into the integ data struct.		# copy the list of observed vars (both continuous and discrete) into the integ data struct from the diffvars struct (which doesn't seem like a great place for that stuff now)

	TODO complete this section.		TODO complete this section.

Jpye at 13:13, 21 March 2015

2015-03-21T13:13:47Z

← Older revision		Revision as of 13:13, 21 March 2015
Line 7:		Line 7:
	# '''<tt>integrator_ida_sort_rels_and_vars</tt>'''		# '''<tt>integrator_ida_sort_rels_and_vars</tt>'''
	# '''<tt>integrator_ida_create_lists</tt>'''		# '''<tt>integrator_ida_create_lists</tt>'''
	# '''<tt>integrator_ida_check_diffindex</tt>'''		# '''<tt>integrator_ida_check_diffindex</tt>''' (performs a series of ''hopefully unnecessary'' checks)
	# (there is some code commented out here to do with checking the structure of the system for structural singularity etc)		# (there is some code commented out here to do with checking the structure of the system for structural singularity etc)
	# '''<tt>integrator_ida_check_index</tt>''' should tell the user if there is an index problem (perhaps we can apply automatic index reduction?)		# '''<tt>integrator_ida_check_index</tt>''' should tell the user if there is an index problem (perhaps we can apply automatic index reduction?)

Jpye at 12:54, 21 March 2015

2015-03-21T12:54:03Z

← Older revision		Revision as of 12:54, 21 March 2015
Line 10:		Line 10:
	# (there is some code commented out here to do with checking the structure of the system for structural singularity etc)		# (there is some code commented out here to do with checking the structure of the system for structural singularity etc)
	# '''<tt>integrator_ida_check_index</tt>''' should tell the user if there is an index problem (perhaps we can apply automatic index reduction?)		# '''<tt>integrator_ida_check_index</tt>''' should tell the user if there is an index problem (perhaps we can apply automatic index reduction?)
	# some checks of the diffvars: do we have a single indep var, is the indep var what we expected it to be		# some checks of the diffvars: do we have a single indep var, is the indep var what we expected it to be.
	# copy the list of observed vars (both continuous and discrete) into the integ data struct.		# copy the list of observed vars (both continuous and discrete) into the integ data struct.

	~~# work out the list of observed variables and store them in <tt>sys->obs</tt>.~~

	TODO complete this section.		TODO complete this section.

Jpye at 12:53, 21 March 2015

2015-03-21T12:53:29Z

← Older revision		Revision as of 12:53, 21 March 2015
Line 1:		Line 1:
	''This pages contains some notes on the analysis algorithm that is used in our [[IDA]] solver in ASCEND. Work in progress!''		''This pages contains some notes on the analysis algorithm that is used in our [[IDA]] solver in ASCEND. Work in progress!''

	# ''<tt>reanalyze_solver_lists</tt>'', to update the rels/vars in the system system according to the WHENs		# '''<tt>reanalyze_solver_lists</tt>''', to update the rels/vars in the system system according to the WHENs
	# set the 'nonbasic' flag to zero for all normal variables, and to one for the independent variable ('x')		# set the 'nonbasic' flag to zero for all normal variables, and to one for the independent variable ('x')
	# ''<tt>integrator_ida_check_vars</tt>'', to check for differential variables that are not incident, downgrading 'differential' variables to algebraic variables if no derivative is present, and marking any...		# '''<tt>integrator_ida_check_vars</tt>''', to check for differential variables that are not incident, downgrading 'differential' variables to algebraic variables if no derivative is present, and marking any...
	# ''<tt>integrator_ida_flag_rels</tt>''		# '''<tt>integrator_ida_flag_rels</tt>'''
	# ''<tt>integrator_ida_sort_rels_and_vars</tt>''		# '''<tt>integrator_ida_sort_rels_and_vars</tt>'''
	# ''<tt>integrator_ida_create_lists</tt>''		# '''<tt>integrator_ida_create_lists</tt>'''
	# ''<tt>integrator_ida_check_diffindex</tt>''		# '''<tt>integrator_ida_check_diffindex</tt>'''
	# (there is some code commented out here to do with checking the structure of the system for structural singularity etc)		# (there is some code commented out here to do with checking the structure of the system for structural singularity etc)
	# ''<tt>integrator_ida_check_index</tt>'' should tell the user if there is an index problem (perhaps we can apply automatic index reduction?)		# '''<tt>integrator_ida_check_index</tt>''' should tell the user if there is an index problem (perhaps we can apply automatic index reduction?)
	# some checks of the diffvars: do we have a single indep var, is the indep var what we expected it to be		# some checks of the diffvars: do we have a single indep var, is the indep var what we expected it to be
	# copy the list of observed vars (both continuous and discrete) into the integ data struct.		# copy the list of observed vars (both continuous and discrete) into the integ data struct.

Jpye at 12:52, 21 March 2015

2015-03-21T12:52:40Z

← Older revision		Revision as of 12:52, 21 March 2015
Line 1:		Line 1:
	''This pages contains some notes on the analysis algorithm that is used in our [[IDA]] solver in ASCEND. Work in progress!''		''This pages contains some notes on the analysis algorithm that is used in our [[IDA]] solver in ASCEND. Work in progress!''

	~~The IDA integrator works a bit differently~~ in the ~~analysis phase~~ to ~~[[DOPRI5]]~~ and ~~[[LSODE]]~~ (it ~~would be nice~~ to be ~~able to unify these things~~).		# ''<tt>reanalyze_solver_lists</tt>'', to update the rels/vars in the system system according to the WHENs
			# set the 'nonbasic' flag to zero for all normal variables, and to one for the independent variable ('x')
			# ''<tt>integrator_ida_check_vars</tt>'', to check for differential variables that are not incident, downgrading 'differential' variables to algebraic variables if no derivative is present, and marking any...
			# ''<tt>integrator_ida_flag_rels</tt>''
			# ''<tt>integrator_ida_sort_rels_and_vars</tt>''
			# ''<tt>integrator_ida_create_lists</tt>''
			# ''<tt>integrator_ida_check_diffindex</tt>''
			# (there is some code commented out here to do with checking the structure of the system for structural singularity etc)
			# ''<tt>integrator_ida_check_index</tt>'' should tell the user if there is an index problem (perhaps we can apply automatic index reduction?)
			# some checks of the diffvars: do we have a single indep var, is the indep var what we expected it to be
			# copy the list of observed vars (both continuous and discrete) into the integ data struct.

	~~See also [[Integrator API~~#~~Analysis\|Analysis]]~~ in ~~the [[Integrator API]]~~.		# work out the list of observed variables and store them in <tt>sys->obs</tt>.

	~~Currently it looks like overkill, and we're hoping that a re-think will help to streamline~~ this ~~code~~.		TODO complete this section.

	~~In <tt>integrator_ida_analyse</tt>, we carefully deal with~~ the ~~case where a variable is declared as differential even when a deriv~~		The IDA integrator works a bit differently in the analysis phase to [[DOPRI5]] and [[LSODE]] (it would be nice to be able to unify these things).

	* <tt>reanalyze_solver_lists</tt>, to update the rels/vars in the ~~system system according to the WHENs~~		See also [[Integrator API#Analysis\|Analysis]] in the [[Integrator API]].
	* <tt>integrator_ida_check_vars</tt>, to check for differential variables that are not incident, downgrading 'differential' variables to algebraic variables if no derivative is present, and marking any
	* run <tt>integrator_ida_flag_rels</tt>, then
	* <tt>integrator_ida_sort_rels_and_vars</tt>.
	* <tt>integrator_ida_create_lists</tt> and
	* <tt>integrator_ida_check_diffindex</tt>. Then
	* <tt>integrator_ida_check_index</tt> checks the index of the DAE system, then
	* work out the list of observed variables and store them in <tt>sys->obs</tt>.

	~~TODO complete this section~~.

	[[Category:Development]]		[[Category:Development]]

Jpye: Created page with "''This pages contains some notes on the analysis algorithm that is used in our IDA solver in ASCEND. Work in progress!'' The IDA integrator works a bit differently in the..."

2015-03-21T12:25:57Z

Created page with "''This pages contains some notes on the analysis algorithm that is used in our IDA solver in ASCEND. Work in progress!'' The IDA integrator works a bit differently in the..."

New page

''This pages contains some notes on the analysis algorithm that is used in our [[IDA]] solver in ASCEND. Work in progress!''

The IDA integrator works a bit differently in the analysis phase to [[DOPRI5]] and [[LSODE]] (it would be nice to be able to unify these things).

See also [[Integrator API#Analysis|Analysis]] in the [[Integrator API]].

Currently it looks like overkill, and we're hoping that a re-think will help to streamline this code.

In <tt>integrator_ida_analyse</tt>, we carefully deal with the case where a variable is declared as differential even when a deriv

* <tt>reanalyze_solver_lists</tt>, to update the rels/vars in the system system according to the WHENs
* <tt>integrator_ida_check_vars</tt>, to check for differential variables that are not incident, downgrading 'differential' variables to algebraic variables if no derivative is present, and marking any
* run <tt>integrator_ida_flag_rels</tt>, then
* <tt>integrator_ida_sort_rels_and_vars</tt>.
* <tt>integrator_ida_create_lists</tt> and
* <tt>integrator_ida_check_diffindex</tt>. Then
* <tt>integrator_ida_check_index</tt> checks the index of the DAE system, then
* work out the list of observed variables and store them in <tt>sys->obs</tt>.

TODO complete this section.

[[Category:Development]]