Vander Zanden, B. (1996) An Incremental Algorithm for Satisfying Hierarchies of Multiway Dataflow Constraints. (TOPLAS), 18 (1). 30-72.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....values through the constraints according to the ordering (this is called executing) Unfortunately, the local propagation algorithms lost generality so they can only be applied to special sets of constraints and comparators. The local propagation algorithms DeltaBlue [13] SkyBlue [12] QuickPlan [15], DETAIL [10] Houria [8] can solve only equality constraints, e.g. linear equations over reals. The exception is the Indigo algorithm [3] for solving inequalities that combines local propagation and refining method. We borrowed the main idea behind the Indigo algorithm, i.e. the propagation of ....

Vander Zanden, B., An Incremental Algorithm for Satisfying Hierarchies of Multi-way Dataflow Constraints, Tech. Report, Department of Computer Science, University of Tennessee, 1995.

....a constraint) advances the state man ager time for recording the variable s history. State manager time and animation 2 VB2 s current constraint solver [13] 19] is unable to Find acyclic solutions of potentially cyclic constraint graphs. An algorithm that removes this limitation is presented in [22]. time are kept separate: state manager time always goes forward and is used to keep track of the successive states of the system; animation time can instead be controlled by the user, to move backwards and forwards in a sequence, and is bound to real time during animation recording and ....

Vander Sanden B (1995) An Incremental Algorithm for Satisfying Hierarchies of Multi-Way, dataflow Constraints. Technical Report, University of Tennesse, Knoxville.

....of typical constraint networks, e.g. in graphical user interfaces. These algorithms gradually solve constraint hierarchies by selecting uniquely satisfiable constraints repeatedly. Many local propagation algorithms were developed for special purposes (DeltaBlue [18] SkyBlue [17] QuickPlan [20], DETAIL [10] Houria [9] Indigo [5] Our generalized approach to solving constraint hierarchies is also primary based 2 Another method for describing over constrained systems is PCSP (Partial Constraint Satisfaction Problems) 3 In [23] the authors also introduce regionally better ....

Vander Zanden, Brad, An Incremental Algorithm for Satisfying Hierarchies of Multiway Dataflow Constraints, Tech. Report, Department of Computer Science, University of Tennessee, March 1995

.... systems, beginning with Ivan Sutherland s pioneering Sketchpad system [Sutherland 1963] Most of the current systems use one way constraints (e.g. Hudson and Smith 1996; Myers 1996] or local propagation algorithms for acyclic collections of multi way constraints (e.g. Sannella et al. 1993; Vander Zanden 1996]) Indigo [Borning et al. 1996] handles acyclic collections of inequality constraints, but not cycles (simultaneous equations and inequalities) User interface systems that handle simultaneous linear equations include DETAIL [Hosobe et al. 1996] and Ultraviolet [Borning and Freeman Benson 1995] A ....

Vander Zanden, B. 1996. An incremental algorithm for satisfying hierarchies of multi-way dataflow constraints. ACM Transactions on Programming Languages and Systems 18, 1 (Jan.), 30--72.

....in each step. In addition, when a variable is repeatedly updated, e.g. by user operation, it can easily evaluate only the necessary constraints to get a new solution. However, local propagation is restricted in some ways. Most local propagation algorithms (DeltaBlue [15] SkyBlue [16] QuickPlan [18], DETAIL [9] Houria [7] can solve only equality constraints, e.g. linear equations over reals. The exception is the Indigo [6] algorithm for solving inequalities that combines local propagation and refining method. The local propagation algorithms also usually use locally predicate comparator ....

Vander Zanden, Brad, An Incremental Algorithm for Satisfying Hierarchies of Multi-way Dataflow Constraints, Tech. Report, Department of Computer Science, University of Tennessee, March 1995

....constraints to get a new solution. This straightforward execution phase is paid off by a foregoing planning phase that choose the order of constraints to satisfy. Local propagation is also restricted in some ways. Most local propagation algorithms (DeltaBlue [20] SkyBlue [19] QuickPlan [22], DETAIL [12] Houria [10] can solve only equality constraints, e.g. linear equations over reals. The exception is the Indigo [6] algorithm for solving inequalities that combines local propagation and refining method. We borrowed the main idea behind the Indigo algorithm, i.e. the propagation ....

....it is a functional constraint cell) The first five points of the constraint network definition are obvious conditions from traditional constraint graphs extended to cover the constraint cells. Thus, the proposed constraint network is a generalization of the former concept of constraint graphs [10,19,20,22]. The new conditions 6 and 7 of the Definition 10 are the contribution of this work. They help us to keep linearity and thus effectiveness of the execution algorithm. As the execution algorithm, computing values of variables, traverses downstream the constraint network, it has to be sure that ....

Vander Zanden, Brad, An Incremental Algorithm for Satisfying Hierarchies of Multi-way Dataflow Constraints, Tech. Report, Department of Computer Science, University of Tennessee, March 1995

....constraints to get a new solution. This straightforward execution phase is paid off by a foregoing planning phase that choose the order of constraints to satisfy. 6 Local propagation is also restricted in some ways. Most local propagation algorithms (DeltaBlue [18] SkyBlue [17] QuickPlan [20], DETAIL [10] Houria [9] can solve only equality constraints, e.g. linear equations over reals. The exception is the Indigo [5] algorithm for solving inequalities that combines local propagation and refining method. We borrowed the main idea behind the Indigo algorithm, i.e. the propagation of ....

....it is a functional constraint cell) The first five points of the constraint network definition are obvious conditions from traditional constraint graphs extended to cover the constraint cells. Thus, the proposed constraint network is a generalization of the former concept of constraint graphs [9,17,18,20]. The new conditions 6 and 7 of the Definition 4 are the contribution of this work. They help us to keep linearity and thus effectiveness of the execution algorithm. As the execution algorithm, computing values of variables, traverses downstream the constraint network, it has to be sure that using ....

Vander Zanden, Brad, An Incremental Algorithm for Satisfying Hierarchies of Multi-way Dataflow Constraints, Tech. Report, Department of Computer Science, University of Tennessee, March 1995

....are rapidly gaining popularity in interactive applications because they simplify the programming task. They are conceptually simple and easy to understand, and are capable of expressing relationships over multiple data types, including numbers, strings, booleans, bitmaps, fonts, and colors [ Vander Zanden, 1996 ] DataAEow constraint solvers are used in numerous interactive systems, such as graphical user interfaces, spreadsheets, graphical layout systems and animation. DataAEow constraints are divided into two main categories. A one way dataAEow constraint has one associated function for recovering ....

....dataAEow constraint is an equation that has one or more methods associated that may be used to satisfy the equation. A method consists of zero or more inputs, one or more outputs, and an arbitrary piece of code that computes the output variables based on the current value of the input variables [Vander Zanden, 1996]. A singleoutput method determines only one variable. A (dataAEow) constraint system is often represented by a constraint graph G c as shown in Figure 1 (a) Local propagation is the technique used to solve multiway constraint systems, typically when new constraints are incrementally added. It ....

[Article contains additional citation context not shown here]

Bradley Vander Zanden. An incremental algorithm for satisfying hierarchies of multiway, dataAEow constraints. ACM Transactions on Programming Languages and Systems, 18(1):3072, January 1996.

....which can be used to find a value for a, b, or c that will satisfy the constraint. Examples of user interface toolkits using one way constraints include Amulet [101] and its predecessor Garnet. Examples of multi way local propagation algorithms include DeltaBlue [111] SkyBlue [110] and QuickPlan [129]. These multi way algorithms all also support constraint hierarchies [11,72] which allow for both required and preferential constraints. Constraint hierarchies are useful in such common User Interface (UI) tasks as specifying which parts of a figure we would prefer to leave fixed while moving ....

B. Vander Zanden. An incremental algorithm for satisfying hierarchies of multi-way dataflow constraints. ACM Transactions on Programming Languages and Systems, 18(1):30--72, January 1996.

....algorithm for solving hierarchies of multi way constraints [70, 71, 72, 73, 74, 75] It addresses simultaneous constraints using pluggable cycle solvers, and handles constraints with multi output methods. QuickPlan is an algorithm for incrementally resolving hierarchies of multi way constraints [86]. It can solve constraint hierarchies if they have at least one acyclic solution graph. CHAPTER 7. RELATED WORK 101 Houria [14] and Houria II [15] are algorithms that solve constraint hierarchies using a certain kind of global hierarchy comparators. Others Techniques for compiling constraint ....

Vander Zanden, B., "An Incremental Algorithm for Satisfying Hierarchies of Multi-Way Dataflow Constraints," ACM Transactions on Programming Languages and Systems, vol. 18, no. 1, Jan. 1996, pp. 30--72.

....objects must use a special function. This function, in addition to returning the value, also sets up a dependency link so that the constraint will be re evaluated when the other object changes. An important research area in user interface software is creating new kinds of constraint solvers (e.g. [5 7]) Therefore, in addition to the standard one way solver described above, Amulet al..so contains an experimental multi way, multi output solver. The QuickPlan constraint solver [5] is also being integrated into Amulet. The Design for the Amulet User Interface Toolkit 5 3.4. Opal Output Model ....

....changes. An important research area in user interface software is creating new kinds of constraint solvers (e.g. 5 7] Therefore, in addition to the standard one way solver described above, Amulet al..so contains an experimental multi way, multi output solver. The QuickPlan constraint solver [5] is also being integrated into Amulet. The Design for the Amulet User Interface Toolkit 5 3.4. Opal Output Model The graphical object layer of Amulet is called Opal, which stands for Object Programming Aggregate Layer. Opal hides the graphics part of Gem and provides a convenient interface to ....

Zanden, B.V., An Incremental Algorithm for Satisfying Hierarchies of Multi-way, Dataflow Constraints , . 1995, Computer Science Department, University of Tennessee. p. 55.

....the planning stage. During execution, each cycle is essentially treated as a single multi output constraint that can be executed using a cycle solver. However, SkyBlue has an exponential running time (the problem of maintaining this type of constraints is NP complete) The QuickPlan algorithm [25] can solve any hierarchy of multi way, multi output, dataflow constraints but adds some restrictions to the general problem. QuickPlan is guaranteed to solve a series of constraints in polynomial time provided that there exists at least one acyclic, conflict free solution. QuickPlan does not ....

Brad Vander Zanden. An Incremental Algorithm for Satisfying Hierarchies of Multi-way, Dataflow Constraints. University of Tennessee Computer Science Department technical report ut-cs-95-282, March 1995.

.... history of using constraints in user interfaces and interactive systems, beginning with Ivan Sutherland s pioneering Sketchpad system [19] Most of the current systems use one way constraints (e.g. 12, 16] or local propagation algorithms for acyclic collections of multi way constraints (e.g. [18, 20]) Indigo [2] handles acyclic collections of inequality constraints, but not cycles (simultaneous equations and inequalities) UI systems that handle simultaneous linear equations include DETAIL [11] and Ultraviolet [3] A number of researchers (including the first author) have experimented with a ....

Brad Vander Zanden. An incremental algorithm for satisfying hierarchies of multi-way dataflow constraints. ACM Transactions on Programming Languages and Systems, 18(1):30--72, January 1996.

....solver (i.e. it is acyclic) The binding mechanism is defined in a declarative way by using indirect constraints [18] 1 VB2 s current constraint solver [17; 28] is unable to find acyclic solutions of potentially cyclic constraint graphs. An algorithm that removes this limitation is presented in [36]. Information control Information display MODEL TOOL v1 v2 c1 c2 bound bound.v1 bound.v2 v1 v2 out variable in variable constraint in out variable direct reference indirect reference Instance (a) b) Figure 1a. Design notation Figure 1b. Model and virtual tool When bound, the tool changes its ....

Vander Zanden B (1995) An Incremental Algorithm for Satisfying Hierarchies of Multi-way, Dataflow Constraints . Technical Report, University of Tennessee, Knoxville.

....of systems, is that of local propagation algorithms for multi way constraints, constraint hierarchies, functional constraints only, and no cycles. These algorithms provide a good balance between expressiveness and efficiency; recent examples include DeltaBlue [19] SkyBlue [18] and QuickPlan [20]. In local propagation algorithms, each constraint has a set of methods that can be used to satisfy the constraint. When a method is executed, it sets one of the constrained variables to a value such that the constraint is satisfied. All of the constraints in a traditional local propagation ....

....d 100. This tightens the bounds on d to [55,100] This propagates to c through the c 25 = d constraint (which is in active constraints) tightening c s bounds to [30,75] We further propagate the change to both a and b through a b = c, so that a s bounds are now [10,55] and b s bounds are [20,65]. Next, we process the medium constraint a = 50. Since 50 is within a s current bounds, we set a s bounds to [50,50] and tighten b s bounds to [20,25] c s bounds to [70,75] and d s bounds to [95,100] Finally we process the absolute weakest stays. The stay on a has no effect, while the stay on ....

[Article contains additional citation context not shown here]

Brad Vander Zanden. An incremental algorithm for satisfying hierarchies of multi-way dataflow constraints. ACM Transactions on Programming Languages and Systems, 18(1):30--72, January 1996.

.... history of using constraints in user interfaces and interactive systems, beginning with Ivan Sutherland s pioneering Sketchpad system [18] Most of the current systems use oneway constraints (e.g. 11, 15] or local propagation algorithms for acyclic collections of multiway constraints (e.g. [17, 19]) Indigo [2] handles acyclic collections of inequality constraints, but not cycles (simultaneous equations and inequalities) UI systems that handle simultaneous linear equations include DETAIL [10] and Ultraviolet [3] A number of researchers (including the second author) have experimented with ....

Brad Vander Zanden. An incremental algorithm for satisfying hierarchies of multi-way dataflow constraints. ACM Transactions on Programming Languages and Systems, 18(1):30--72, January 1996.

....sb OpenPlan sb is a specialized version of an algorithm called OpenPlan: the procedure select free block of OpenPlan can select any free block whereas select freeblock sb imposes restrictions. OpenPlan is based on the PDOF algorithm used for maintaining constraints in interactive applications [Vander Zanden, 1996]. It builds a DAG of blocks in reverse order from the leaves to the roots. A free block has variables which are linked only to constraints within the block. Iteratively selecting and removing blocks which are free ensures that a DAG of blocks is built, that is, that no directed cycle can appear ....

Bradley Vander Zanden. An incremental algorithm for satisfying hierarchies of multi-way, dataAEow constraints. ACM Transactions on Programming Languages and Systems, 18(1):3072, January 1996.

.... history of using constraints in user interfaces and interactive systems, beginning with Ivan Sutherland s pioneering Sketchpad system [20] Most of the current systems use one way constraints (e.g. 13, 17] or local propagation algorithms for acyclic collections of multi way constraints (e.g. [19, 21]) Indigo [2] handles acyclic collections of inequality constraints, but not cycles (simultaneous equations and inequalities) UI systems that handle simultaneous linear equations include DETAIL [12] and Ultraviolet [3] A number of researchers (including the first author) have experimented with a ....

B. Vander Zanden. An incremental algorithm for satisfying hierarchies of multi-way dataflow constraints. ACM TOPLAS, 18(1):30--72, Jan 1996.

....a constraint) advances the state manager time for recording the variable s history. State manager time and animation 2 VB2 s current constraint solver [13] 19] is unable to find acyclic solutions of potentially cyclic constraint graphs. An algorithm that removes this limitation is presented in [22]. time are kept separate: state manager time always goes forward and is used to keep track of the successive states of the system; animation time can instead be controlled by the user, to move backwards and forwards in a sequence, and is bound to real time during animation recording and ....

Vander Zanden B (1995) An Incremental Algorithm for Satisfying Hierarchies of Multi-Way, dataflow Constraints. Technical Report, University of Tennesse, Knoxville.

....side effects. However, if the constraints calculate and set different values, an infinite loop can result. The Amulet Environment 21 Submitted for Publication 4.3.4. Multiple Solvers An important research area in user interface software is creating new kinds of constraint solvers (e.g. [6, 9, 29]) Therefore, Amulet contains an architecture that allows multiple solvers to coexist. Currently, in addition to the one way solver described above, Amulet supports a multi output, multi way solver called a web and an animation constraint solver. The web constraint can have an arbitrary number ....

....is created, changes to the prototype are not reflected in the instances. Finally, SELF does not support constraints. There are many research systems which support constraints. The idea for indirect constraints and integrating constraints with a prototype instance object system originated in Garnet [29]. EVAL vite [8] integrates constraints with C by using a preprocessor and a special sub language for the constraints. EVAL vite is a one way solver like Amulet s formula constraints. MultiGarnet [28] integrated a multi way solver with Garnet s oneway solver, and inspired Amulet s goal for ....

B. Vander Zanden, An Incremental Algorithm for Satisfying Hierarchies of Multi-way, Dataflow Constraints . Computer Science Department, University of Tennessee Mar, 1995.

....even if the constraints contain cycles of dependencies and side effects. However, if the constraints calculate and set different values, an infinite loop can result. 4.3. 4 Multiple Solvers An important research area in user interface software is creating new kinds of constraint solvers (e.g. [6, 9, 30]) Therefore, Amulet contains an architecture that allows multiple solvers to co exist. Currently, in addition to the one way solver described above, Amulet supports a multi output, multi way solver called a web, and an animation constraint solver. The Amulet Environment 20 The web ....

....is created, changes to the prototype are not reflected in the instances. Finally, SELF does not support constraints. There are many research systems which support constraints. The idea for indirect constraints and integrating constraints with a prototype instance object system originated in Garnet [30]. EVAL vite [8] integrates constraints with C by using a preprocessor and a special sub language for the constraints. EVAL vite is a one way solver like Amulet s formula constraints. MultiGarnet [29] integrated a multi way solver with Garnet s oneway solver, and inspired Amulet s goal for ....

B. Vander Zanden, "An Incremental Algorithm for Satisfying Hierarchies of Multiway, Dataflow Constraints," 1995, Computer Science Department, University of Tennessee: 55.

....with Ivan Sutherland s pioneering Sketchpad system [14] 1 Bjorn Freeman Benson, Object Technology International, Personal Communication. Most of the current systems use one way constraints (e.g. 9, 10] or local propagation algorithms for acyclic collections of multi way constraints (e.g. [12, 15]) Indigo [2] handles acyclic collections of inequality constraints, but not cycles. UI systems that handle simultaneous (cyclic) linear equations include DETAIL [8] and Ultraviolet [3] UI systems that handle simultaneous linear inequalities as well with reasonable efficiency are QOCA [7] and ....

B. Vander Zanden. An incremental algorithm for satisfying hierarchies of multi-way dataflow constraints. ACM TOPLAS, 18(1):30--72, 1996.

....of benchmarks are modified versions of the first set of benchmarks and involve multi output, potentially cyclic constraint hierarchies. These benchmarks are illustrated in Figure 17 and the results are summarized in Table 4 (the Sannella benchmarks are illustrated elsewhere [Sannella et al. 1993; Vander Zanden 1995] and are very similar in appearance to the ones shown in Figure 17) Graphs for a representative set of benchmarks, the chain and multi chain benchmarks, are shown in Figure 18. Table 3: Time required by QuickPlan and SkyBlue on benchmarks involving single output, acyclic constraint hierarchies. ....

Vander Zanden, B. 1995. An incremental algorithm for satisfying hierarchies of multi-way, dataflow constraints. Tech. Rep. CS-95-282 (Mar), Computer Science Department, University of Tennessee.

....been applied to other application areas including circuits [1] graphical interfaces [10, 11, 13, 14, 18, 25, 19] and spreadsheets. Multi way, multi output dataflow constraint systems have also been developed for graphical interfaces, including ThingLab [3, 8, 23] Kaleidoscope [7] and MultiGarnet [22, 21, 24]. Multi way constraints are more powerful than one way constraints, but one way constraints suffice for many applications and in general are more easily managed by programmers. Researchers have adopted various approaches to storage optimization for dataflow constraints. Constant propagation ....

VANDER ZANDEN, B. An incremental algorithm for satisfying hierarchies of multi-way, dataflow constraints. ACM Transactions on Programming Languages and Systems 18, 1 (January 1996), 30--72.

....permit components of dynamic data structures to be constrained in a flexible and elegant fashion. The Amulet graphical interface toolkit serves as the medium for our work. We have extended its constraint system to use model dependencies. Multiway, multi output constraint systems are more powerful [4, 17, 19], but one way systems suffice for many applications and in general are more easily managed by programmers. Researchers have adopted various approaches to constraint optimization. Constant propagation allows some constraints to be removed from the system completely [12, 13] If all the parameters ....

Vander Zanden, B. An incremental algorithm for satisfying hierarchies of multi-way, dataflow constraints. ACM Transactions on Programming Languages and Systems 18, 1 (January 1996), 30--72.

No context found.

Vander Zanden, B. (1996) An Incremental Algorithm for Satisfying Hierarchies of Multiway Dataflow Constraints. (TOPLAS), 18 (1). 30-72.

No context found.

B. Vander Zanden. An incremental algorithm for satisfying hierarchies of multi-way, dataflow constraints. ACM Trans. on Prog. Languages and Systems, 18(1):30--72, 1996.

No context found.

Vander Zanden, B. (1996) An Incremental Algorithm for Satisfying Hierarchies of Multiway Dataflow Constraints. (TOPLAS), 18 (1). 30-72.

No context found.

Vander Zanden, Brad. An Incremental Algorithm for Satisfying Hierarchies of Multi-way, Dataflow Constraints. University of Tennessee Computer Science Department technical report ut-cs-95-282, March 1995.

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