ModelExplorer: defined vars #232

CHANGES.mp.md

@@ -2,17 +2,32 @@ Summary of recent updates to the AMPL MP Library
 ================================================
 
 
-## unreleased
+## 20240319
+- *SOS constraints*.
+  - Fixed handling of SOS2 constraints created by AMPL
+    as reformulations of PL expressions (`option
+    pl_linearize 1`, default; set to 0 to use the solver's
+    native PL functions if supported, or MP linearization.)
+  - Disallow repeated weights for SOS constraints
+    (suffixes `.sosno`/`.ref`.)
+- *Reformulation explorer*.
+  - Upgraded option `writegraph` exports the reformulation
+    graph which can be explored with the script in
+    support/modelexplore (WIP.)
 - *Native handling of POW(x, INT)*.
   - Power expressions with positive integer exponent
     are passed natively to the solvers accepting them,
     vs previously quadratic or linear reformulation.
   - For best performance, global solving capability
     might be needed (e.g., Gurobi: `global=1`.)
-- *Unused acc: options*.
-  - The constraint acceptance options *acc:...*
+- *Option `report_times`*.
+- *Unused `acc:` options*.
+  - The constraint acceptance options `acc:...`
     for non-handled constraints are ignored
     (previously triggered error.)
+- *NLWPY*.
+  - Python NL Writer API for MIQP models.
+  - Available on PyPI.
 
 
 ## 20240115

CMakeLists.txt

@@ -233,7 +233,7 @@ endif()  ## NOT SKIP_BUILD_MP
 include_directories(include)
 
 set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
-set(MP_DATE 20240115)
+set(MP_DATE 20240319)
 
 set(MP_SYSINFO "${CMAKE_SYSTEM_NAME} ${CMAKE_SYSTEM_PROCESSOR}")
 

src/expr-writer.h

@@ -330,11 +330,7 @@ void ExprWriter<ExprTypes, VN>::VisitPLTerm(PLTerm e) {
   for (int i = 1, n = e.num_slopes(); i < n; ++i)
     writer_ << ", " << e.slope(i);
   writer_ << ">> ";
-  NumericExpr arg = e.arg();
-  if (Variable var = ExprTypes::template Cast<Variable>(arg))
-    writer_ << "x" << (var.index() + 1);
-  else
-    writer_ << "e" << ((ExprTypes::template Cast<CommonExpr>(arg)).index() + 1);
+  Visit( e.arg() );
 }
 
 template <typename ExprTypes, typename VN>

support/modelexplore/scripts/python/model.py

@@ -17,6 +17,7 @@ def __init__(self):
     self._graph = DiGraph()    ## Underlyng graph
 
     self._vars = []            ## Pointers to various parts of the graph
+    self._dvars = []
     self._cons_NL_all = []
     self._cons_NL = {        ## NL + SOS
       "All" : [],
@@ -31,6 +32,9 @@ def __init__(self):
   def UpdateVar(self, idx, data):
     self._updateNodeData(self._vars, idx, data)
 
+  def UpdateDefVar(self, idx, data):
+    self._updateNodeData(self._dvars, idx, data)
+
   def UpdateNLObj(self, idx, data):
     self._updateNodeData(self._objs_NL, idx, data)
 
@@ -75,6 +79,7 @@ def _updateMap(self, data1, data2):
   def MatchOrigModel(self, keyw):
     result = {}
     result["NL Variables"] = self._matchRecords(self._vars, keyw, "is_from_nl")
+    result["NL Defined Variables"] = self._matchRecords(self._dvars, keyw)
     result["NL Objectives"] = self._matchRecords(self._objs_NL, keyw)
     result["NL Constraints"] \
       = self._matchRecords(self._cons_NL.get("All"), keyw)

support/modelexplore/scripts/python/modelreader.py

@@ -31,6 +31,8 @@ def _processLine(self, line: str):
   def _addDataChunk(self, chunk):
     if "VAR_index" in chunk:
       self._model.UpdateVar(chunk["VAR_index"], chunk)
+    elif "NL_COMMON_EXPR_index" in chunk:
+      self._model.UpdateDefVar(chunk["NL_COMMON_EXPR_index"], chunk)
     elif "NL_OBJECTIVE_index" in chunk:
       self._model.UpdateNLObj(chunk["NL_OBJECTIVE_index"], chunk)
     elif "NL_CON_TYPE" in chunk: