Clarify that some algorithms are specialized to particular problem classes

Author: odow

README.md

@@ -51,22 +51,24 @@ the choice of solution algorithm.
 
 ## Algorithm
 
-Set the algorithm using the `MOA.Algorithm()` attribute.
-
-The value must be one of the algorithms supported by MOA:
-
- * `MOA.Chalmet()`
- * `MOA.Dichotomy()`
- * `MOA.DominguezRios()`
- * `MOA.EpsilonConstraint()`
- * `MOA.Hierarchical()`
- * `MOA.KirlikSayin()`
- * `MOA.Lexicographic()` [default]
- * `MOA.RandomWeighting()`
- * `MOA.Sandwiching()`
- * `MOA.TambyVanderpooten()`
-
-Consult their docstrings for details.
+Set the algorithm using the `MOA.Algorithm()` attribute. The value must be one
+of the algorithms supported by MOA. Consult their docstrings for details.
+
+Some algorithms are restricted to certain problem classes. The solution set
+depends on the algorithm and the problem class.
+
+| `MOA.Algorithm`           | Applicable problem class |
+| :------------------------ | ------------------------ |
+| `MOA.Chalmet()`           | Exactly two objectives   |
+| `MOA.Dichotomy()`         | Exactly two objectives   |
+| `MOA.DominguezRios()`     | Discrete variables only  |
+| `MOA.EpsilonConstraint()` | Exactly two objectives   |
+| `MOA.Hierarchical()`      | Any                      |
+| `MOA.KirlikSayin()`       | Discrete variables only  |
+| `MOA.Lexicographic()` [default] | Any                |
+| `MOA.RandomWeighting()`   | Any                      |
+| `MOA.Sandwiching()`       | Any                      |
+| `MOA.TambyVanderpooten()` | Discrete variables only  |
 
 ## Other optimizer attributes
 

src/algorithms/Chalmet.jl

@@ -12,6 +12,12 @@ Chalmet, L.G., and Lemonidis, L., and Elzinga, D.J. (1986). An algorithm for the
 bi-criterion integer programming problem. European Journal of Operational
 Research. 25(2), 292-300
 
+## Supported problem classes
+
+This algorithm is restricted to problems with:
+
+ * exactly two objectives
+
 ## Supported optimizer attributes
 
  * `MOI.TimeLimitSec()`: terminate if the time limit is exceeded and return the

src/algorithms/Dichotomy.jl

@@ -11,6 +11,12 @@ A solver that implements the algorithm of:
 Y. P. Aneja, K. P. K. Nair, (1979) Bicriteria Transportation Problem. Management
 Science 25(1), 73-78.
 
+## Supported problem classes
+
+This algorithm is restricted to problems with:
+
+ * exactly two objectives
+
 ## Supported optimizer attributes
 
  * `MOI.TimeLimitSec()`: terminate if the time limit is exceeded and return the

src/algorithms/DominguezRios.jl

@@ -12,6 +12,13 @@ Dominguez-Rios, M.A. & Chicano, F., & Alba, E. (2021). Effective anytime
 algorithm for multiobjective combinatorial optimization problems. Information
 Sciences, 565(7), 210-228.
 
+## Supported problem classes
+
+This algorithm is restricted to problems with:
+
+ * discrete variables only. It will fail to converge if the problem is purely
+   continuous.
+
 ## Supported optimizer attributes
 
  * `MOI.TimeLimitSec()`: terminate if the time limit is exceeded and return the

src/algorithms/EpsilonConstraint.jl

@@ -9,6 +9,12 @@
 `EpsilonConstraint` implements the epsilon-constraint algorithm for
 bi-objective programs.
 
+## Supported problem classes
+
+This algorithm is restricted to problems with:
+
+ * exactly two objectives
+
 ## Supported optimizer attributes
 
  * `MOA.EpsilonConstraintStep()`: `EpsilonConstraint` uses this value

src/algorithms/Hierarchical.jl

@@ -19,6 +19,10 @@ future solves. Finally, it steps to the next set of prioritized objectives.
 The solution is a single point that trades off the various objectives. It does
 not record the partial solutions that were found along the way.
 
+## Supported problem classes
+
+This algorithm supports all problem classes.
+
 ## Supported optimizer attributes
 
  * `MOA.ObjectivePriority`

src/algorithms/KirlikSayin.jl

@@ -17,6 +17,13 @@ discrete optimization problems. The algorithm maintains `(p-1)`-dimensional
 rectangle regions in the solution space, and a two-stage optimization problem
 is solved for each rectangle.
 
+## Supported problem classes
+
+This algorithm is restricted to problems with:
+
+ * discrete variables only. It will fail to converge if the problem is purely
+   continuous.
+
 ## Supported optimizer attributes
 
  * `MOI.TimeLimitSec()`: terminate if the time limit is exceeded and return the

src/algorithms/Lexicographic.jl

@@ -9,6 +9,10 @@
 `Lexicographic()` implements a lexigographic algorithm that returns a single
 point on the frontier, corresponding to solving each objective in order.
 
+## Supported problem classes
+
+This algorithm supports all problem classes.
+
 ## Supported optimizer attributes
 
  * `MOI.TimeLimitSec()`: terminate if the time limit is exceeded and return the

src/algorithms/RandomWeighting.jl

@@ -9,6 +9,10 @@
 A heuristic solver that works by repeatedly solving a weighted sum problem with
 random weights.
 
+## Supported problem classes
+
+This algorithm supports all problem classes.
+
 ## Supported optimizer attributes
 
  * `MOI.TimeLimitSec()`: terminate if the time limit is exceeded and return the

src/algorithms/Sandwiching.jl

@@ -11,6 +11,10 @@ Fleuren, H. A. (2023). A Renewed Take on Weighted Sum in Sandwich Algorithms:
 Modification of the Criterion Space. (Center Discussion Paper; Vol. 2023-012).
 CentER, Center for Economic Research.
 
+## Supported problem classes
+
+This algorithm supports all problem classes.
+
 ## Compat
 
 To use this algorithm you MUST first load the Polyhedra.jl Julia package: