Merge pull request #6 from MatProGo-dev/kr-feature-problem1

Introducing the Problem Object

Author: kwesiRutledge

.github/workflows/coverage1.yaml

@@ -2,7 +2,7 @@ name: Go  # The name of the workflow that will appear on Github
 
 on:
   push:
-    branches: [ main , kr-feature-multiply1 ]
+    branches: [ main , kr-feature-problem1 ]
   pull_request:
     branches: [ main ]
   # Allows you to run this workflow manually from the Actions tab

README.md

@@ -140,8 +140,8 @@ code. Hopefully, this is avoided using this format.
 * [ ] Decide whether or not we really need the Coeffs() method (What is it doing?)
 * [ ] Write changes to all AtVec() methods to output both elements AND errors (so we can detect out of length calls)
 * [ ] Determine whether or not to keep the Solution and Solver() interfaces in this module. It seems like they can be solver-specific.
-* [ ] Introduce MatrixVar object
 * [ ] Add Check() to:
   * [ ] Expression
   * [ ] ScalarExpression
-  * [ ] VectorExpression interfaces
+  * [ ] VectorExpression interfaces
+* [ ] Add ToSymbolic() Method for ALL expressions

go.mod

@@ -1,8 +1,7 @@
 module github.com/MatProGo-dev/MatProInterface.go
 
-go 1.19
+go 1.21
 
-require (
-	github.com/hashicorp/go-version v1.6.0
-	gonum.org/v1/gonum v0.12.0
-)
+require gonum.org/v1/gonum v0.14.0
+
+require github.com/MatProGo-dev/SymbolicMath.go v0.1.4

go.sum

@@ -1,5 +1,16 @@
-github.com/hashicorp/go-version v1.6.0 h1:feTTfFNnjP967rlCxM/I9g701jU+RN74YKx2mOkIeek=
-github.com/hashicorp/go-version v1.6.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
-golang.org/x/exp v0.0.0-20191002040644-a1355ae1e2c3 h1:n9HxLrNxWWtEb1cA950nuEEj3QnKbtsCJ6KjcgisNUs=
-gonum.org/v1/gonum v0.12.0 h1:xKuo6hzt+gMav00meVPUlXwSdoEJP46BR+wdxQEFK2o=
-gonum.org/v1/gonum v0.12.0/go.mod h1:73TDxJfAAHeA8Mk9mf8NlIppyhQNo5GLTcYeqgo2lvY=
+github.com/MatProGo-dev/SymbolicMath.go v0.0.0-20240104201035-f9a42f642121 h1:nnJVXcnTvAdkfR4kZRBw4Ot+KoL8S3PijlLTmKOooco=
+github.com/MatProGo-dev/SymbolicMath.go v0.0.0-20240104201035-f9a42f642121/go.mod h1:gKbGR/6sYWi2koMUEDIPWBPi6jQPELKle0ijIM+eaHU=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.0 h1:FUwLQZzZhtgGj6WKyuwQE74P9UYhgbNr5eD5f8zzuu8=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.0/go.mod h1:gKbGR/6sYWi2koMUEDIPWBPi6jQPELKle0ijIM+eaHU=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.1 h1:YigpL7w5D8qLu0xzDAayMXePBh9LK0/w3ykvuoVZwXQ=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.1/go.mod h1:gKbGR/6sYWi2koMUEDIPWBPi6jQPELKle0ijIM+eaHU=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.2 h1:9tYbiHWm0doXOSipd02pxtENqBU8WhmHTrDXetPW+ms=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.2/go.mod h1:gKbGR/6sYWi2koMUEDIPWBPi6jQPELKle0ijIM+eaHU=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.3 h1:IeofFqvZ/jAO6LywlZR/UMl5t/KOyMAvvctVgTzvgHI=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.3/go.mod h1:gKbGR/6sYWi2koMUEDIPWBPi6jQPELKle0ijIM+eaHU=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.4 h1:6DaDRYoANmKMkZL0uSUSx7Ibx8Hc9S6AX+7L0hIy1A4=
+github.com/MatProGo-dev/SymbolicMath.go v0.1.4/go.mod h1:gKbGR/6sYWi2koMUEDIPWBPi6jQPELKle0ijIM+eaHU=
+golang.org/x/exp v0.0.0-20230321023759-10a507213a29 h1:ooxPy7fPvB4kwsA2h+iBNHkAbp/4JxTSwCmvdjEYmug=
+golang.org/x/exp v0.0.0-20230321023759-10a507213a29/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
+gonum.org/v1/gonum v0.14.0 h1:2NiG67LD1tEH0D7kM+ps2V+fXmsAnpUeec7n8tcr4S0=
+gonum.org/v1/gonum v0.14.0/go.mod h1:AoWeoz0becf9QMWtE8iWXNXc27fK4fNeHNf/oMejGfU=

optim/constant.go

@@ -2,6 +2,7 @@ package optim
 
 import (
 	"fmt"
+	"github.com/MatProGo-dev/SymbolicMath.go/symbolic"
 	"gonum.org/v1/gonum/mat"
 )
 
@@ -246,3 +247,14 @@ func (c K) Check() error {
 func (c K) Transpose() Expression {
 	return c
 }
+
+/*
+ToSymbolic
+Description:
+
+	Converts the constant to a symbolic expression (i.e., one that uses the
+	symbolic math toolbox).
+*/
+func (c K) ToSymbolic() (symbolic.Expression, error) {
+	return symbolic.K(c), nil
+}

optim/constr_sense.go

@@ -0,0 +1,52 @@
+package optim
+
+import "github.com/MatProGo-dev/SymbolicMath.go/symbolic"
+
+// ConstrSense represents if the constraint x <= y, x >= y, or x == y. For easy
+// integration with Gurobi, the senses have been encoding using a byte in
+// the same way Gurobi encodes the constraint senses.
+type ConstrSense byte
+
+// Different constraint senses conforming to Gurobi's encoding.
+const (
+	SenseEqual            ConstrSense = '='
+	SenseLessThanEqual                = '<'
+	SenseGreaterThanEqual             = '>'
+)
+
+/*
+ToSymbolic
+Description:
+
+	Converts a constraint sense to a the appropriate representation
+	in the symbolic math toolbox.
+*/
+func (cs ConstrSense) ToSymbolic() symbolic.ConstrSense {
+	switch cs {
+	case SenseEqual:
+		return symbolic.SenseEqual
+	case SenseLessThanEqual:
+		return symbolic.SenseLessThanEqual
+	case SenseGreaterThanEqual:
+		return symbolic.SenseGreaterThanEqual
+	}
+	return '1'
+}
+
+/*
+String
+Description:
+
+	Returns the string representation of the constraint sense.
+*/
+func (cs ConstrSense) String() string {
+	switch cs {
+	case SenseEqual:
+		return "=="
+	case SenseLessThanEqual:
+		return "<="
+	case SenseGreaterThanEqual:
+		return ">="
+	}
+	return "UNRECOGNIZED ConstrSense"
+}

optim/constraint.go

@@ -10,6 +10,8 @@ Description:
 type Constraint interface {
 	Left() Expression
 	Right() Expression
+	ConstrSense() ConstrSense
+	Check() error
 }
 
 func IsConstraint(c interface{}) bool {

optim/expression.go

@@ -2,6 +2,7 @@ package optim
 
 import (
 	"fmt"
+	"github.com/MatProGo-dev/SymbolicMath.go/symbolic"
 )
 
 /*
@@ -52,6 +53,10 @@ type Expression interface {
 
 	// Comparison
 	Comparison(rightIn interface{}, sense ConstrSense, errors ...error) (Constraint, error)
+
+	//ToSymbolic
+	// Converts the expression to a symbolic expression (in SymbolicMath.go)
+	ToSymbolic() (symbolic.Expression, error)
 }
 
 /*

optim/model.go

@@ -2,7 +2,6 @@ package optim
 
 import (
 	"fmt"
-	"time"
 )
 
 // Model represents the overall constrained linear optimization model to be
@@ -14,24 +13,12 @@ type Model struct {
 	Variables   []Variable
 	Constraints []Constraint
 	Obj         *Objective
-	ShowLog     bool
-	TimeLimit   time.Duration
 }
 
 // NewModel returns a new model with some default arguments such as not to show
-// the log and no time limit.
+// the log.
 func NewModel(name string) *Model {
-	return &Model{Name: name, ShowLog: false}
-}
-
-//// ShowLog instructs the solver to show the log or not.
-//func (m *Model) ShowLog(shouldShow bool) {
-//	m.ShowLog = shouldShow
-//}
-
-// SetTimeLimit sets the solver time limit for the model.
-func (m *Model) SetTimeLimit(dur time.Duration) {
-	m.TimeLimit = dur
+	return &Model{Name: name}
 }
 
 /*
@@ -168,47 +155,24 @@ func (m *Model) SetObjective(e Expression, sense ObjSense) error {
 	return nil
 }
 
-//// Optimize optimizes the model using the given solver type and returns the
-//// solution or an error.
-//func (m *Model) Optimize(solver Solver) (*Solution, error) {
-//	// Variables
-//	var err error
-//
-//	// Input Processing
-//	if len(m.Variables) == 0 {
-//		return nil, errors.New("no variables in model")
-//	}
-//
-//	solver.ShowLog(m.ShowLog)
-//
-//	if m.TimeLimit > 0 {
-//		solver.SetTimeLimit(m.TimeLimit.Seconds())
-//	}
-//
-//	solver.AddVariables(m.Variables)
-//
-//	for _, constr := range m.Constraints {
-//		solver.AddConstraint(constr)
-//	}
-//
-//	mipSol, err := solver.Optimize()
-//	defer solver.DeleteSolver()
-//
-//	if err != nil {
-//		return nil, fmt.Errorf("There was an issue while trying to optimize the model: %v", err)
-//	}
-//
-//	if mipSol.Status != OptimizationStatus_OPTIMAL {
-//		errorMessage, err := mipSol.Status.ToMessage()
-//		if err != nil {
-//			return nil, fmt.Errorf("There was an issue converting optimization status to a message: %v", err)
-//		}
-//		return nil, fmt.Errorf(
-//			"[Code = %d] %s",
-//			mipSol.Status,
-//			errorMessage,
-//		)
-//	}
-//
-//	return &mipSol, nil
-//}
+/*
+Check
+Description:
+
+	Checks the model for errors.
+*/
+func (m *Model) Check() error {
+	// Constants
+
+	// Verifiy that there is at least one variable in the model.
+	if len(m.Variables) == 0 {
+		return fmt.Errorf("the model has no variables!")
+	}
+
+	// It's okay if there are no constraints.
+
+	// It's okay if there is not an objective.
+
+	// All Checks have passed.
+	return nil
+}

optim/scalar_constraint.go

@@ -19,6 +19,10 @@ func (sc ScalarConstraint) Right() Expression {
 	return sc.RightHandSide
 }
 
+func (sc ScalarConstraint) ConstrSense() ConstrSense {
+	return sc.Sense
+}
+
 /*
 IsLinear
 Description:
@@ -106,14 +110,38 @@ func (sc ScalarConstraint) Simplify() (ScalarConstraint, error) {
 
 }
 
-// ConstrSense represents if the constraint x <= y, x >= y, or x == y. For easy
-// integration with Gurobi, the senses have been encoding using a byte in
-// the same way Gurobi encodes the constraint senses.
-type ConstrSense byte
-
-// Different constraint senses conforming to Gurobi's encoding.
-const (
-	SenseEqual            ConstrSense = '='
-	SenseLessThanEqual                = '<'
-	SenseGreaterThanEqual             = '>'
-)
+/*
+Check
+Description:
+
+	Checks the validity of the ScalarConstraint, this makes sure that:
+	- The Sense if either SenseEqual, SenseLessThanEqual, or SenseGreaterThanEqual
+*/
+func (sc ScalarConstraint) Check() error {
+	// Check sense
+	switch sc.Sense {
+	case SenseEqual:
+		break
+	case SenseLessThanEqual:
+		break
+	case SenseGreaterThanEqual:
+		break
+	default:
+		return fmt.Errorf("the constraint sense is not recognized.")
+	}
+
+	// Check left and right hand sides
+	err := sc.LeftHandSide.Check()
+	if err != nil {
+		return fmt.Errorf("left hand side of the constraint is not valid: %v", err)
+	}
+
+	// Check right hand side
+	err = sc.RightHandSide.Check()
+	if err != nil {
+		return fmt.Errorf("right hand side of the constraint is not valid: %v", err)
+	}
+
+	// Return
+	return nil
+}

optim/scalar_expression.go

@@ -2,6 +2,7 @@ package optim
 
 import (
 	"fmt"
+	"github.com/MatProGo-dev/SymbolicMath.go/symbolic"
 )
 
 // ScalarExpression represents a linear general expression of the form
@@ -58,6 +59,13 @@ type ScalarExpression interface {
 
 	//Transpose returns the transpose of the given vector expression
 	Transpose() Expression
+
+	//ToSymbolic Returns the symbolic version of the scalar expression
+	// (i.e., the expression when declared using the symbolic math toolbox).
+	ToSymbolic() (symbolic.Expression, error)
+
+	// Check, checks the expression for any errors
+	Check() error
 }
 
 // NewExpr returns a new expression with a single additive constant value, c,

optim/scalar_linear_expr.go

@@ -2,6 +2,7 @@ package optim
 
 import (
 	"fmt"
+	"github.com/MatProGo-dev/SymbolicMath.go/symbolic"
 	"gonum.org/v1/gonum/mat"
 )
 
@@ -421,3 +422,30 @@ Description:
 func (sle ScalarLinearExpr) Transpose() Expression {
 	return sle
 }
+
+/*
+ToSymbolic
+Description:
+
+	Converts the constant to a symbolic expression (i.e., one that uses the
+	symbolic math toolbox).
+*/
+func (sle ScalarLinearExpr) ToSymbolic() (symbolic.Expression, error) {
+	// Check for errors
+	err := sle.Check()
+	if err != nil {
+		return nil, err
+	}
+
+	// Compute product of L and X
+	symX, err := sle.X.ToSymbolic()
+	if err != nil {
+		return nil, err
+	}
+
+	tempProduct := symbolic.VecDenseToKVector(sle.L).Transpose().Multiply(symX)
+
+	// Add C
+	return tempProduct.Plus(symbolic.K(sle.C)), nil
+
+}