Rename RequestType to Operation

Author: vladimir-ch

backtracking.go

@@ -33,7 +33,7 @@ type Backtracking struct {
 	initG    float64
 }
 
-func (b *Backtracking) Init(f, g float64, step float64) RequestType {
+func (b *Backtracking) Init(f, g float64, step float64) Operation {
 	if step <= 0 {
 		panic("backtracking: bad step size")
 	}
@@ -64,10 +64,10 @@ func (b *Backtracking) Finished(f, _ float64) bool {
 	return ArmijoConditionMet(f, b.initF, b.initG, b.stepSize, b.FuncConst)
 }
 
-func (b *Backtracking) Iterate(_, _ float64) (float64, RequestType, error) {
+func (b *Backtracking) Iterate(_, _ float64) (float64, Operation, error) {
 	b.stepSize *= b.Decrease
 	if b.stepSize < minimumBacktrackingStepSize {
-		return 0, NoRequest, ErrLinesearchFailure
+		return 0, NoOperation, ErrLinesearchFailure
 	}
 	return b.stepSize, FuncEvaluation, nil
 }

bfgs.go

@@ -39,7 +39,7 @@ type BFGS struct {
 	first bool // Is it the first iteration (used to set the scale of the initial hessian)
 }
 
-func (b *BFGS) Init(loc *Location) (RequestType, error) {
+func (b *BFGS) Init(loc *Location) (Operation, error) {
 	if b.Linesearcher == nil {
 		b.Linesearcher = &Bisection{}
 	}
@@ -52,7 +52,7 @@ func (b *BFGS) Init(loc *Location) (RequestType, error) {
 	return b.ls.Init(loc)
 }
 
-func (b *BFGS) Iterate(loc *Location) (RequestType, error) {
+func (b *BFGS) Iterate(loc *Location) (Operation, error) {
 	return b.ls.Iterate(loc)
 }
 

bisection.go

@@ -26,7 +26,7 @@ type Bisection struct {
 	maxGrad  float64
 }
 
-func (b *Bisection) Init(f, g float64, step float64) RequestType {
+func (b *Bisection) Init(f, g float64, step float64) Operation {
 	if step <= 0 {
 		panic("bisection: bad step size")
 	}
@@ -73,7 +73,7 @@ func (b *Bisection) Finished(f, g float64) bool {
 	return false
 }
 
-func (b *Bisection) Iterate(f, g float64) (float64, RequestType, error) {
+func (b *Bisection) Iterate(f, g float64) (float64, Operation, error) {
 	// Deciding on the next step size
 	if math.IsInf(b.maxStep, 1) {
 		// Have not yet bounded the minimum
@@ -135,10 +135,10 @@ func (b *Bisection) Iterate(f, g float64) (float64, RequestType, error) {
 // both of which indicate the minimization must stop. If the steps are different,
 // it sets the new step size and returns the step and evaluation type. If the steps
 // are the same, it returns an error.
-func (b *Bisection) checkStepEqual(newStep float64, r RequestType) (float64, RequestType, error) {
+func (b *Bisection) checkStepEqual(newStep float64, op Operation) (float64, Operation, error) {
 	if b.currStep == newStep {
-		return b.currStep, NoRequest, ErrLinesearchFailure
+		return b.currStep, NoOperation, ErrLinesearchFailure
 	}
 	b.currStep = newStep
-	return newStep, r, nil
+	return newStep, op, nil
 }

cg.go

@@ -94,7 +94,7 @@ type CG struct {
 	gradPrevNorm float64
 }
 
-func (cg *CG) Init(loc *Location) (RequestType, error) {
+func (cg *CG) Init(loc *Location) (Operation, error) {
 	if cg.IterationRestartFactor < 0 {
 		panic("cg: IterationRestartFactor is negative")
 	}
@@ -128,7 +128,7 @@ func (cg *CG) Init(loc *Location) (RequestType, error) {
 	return cg.ls.Init(loc)
 }
 
-func (cg *CG) Iterate(loc *Location) (RequestType, error) {
+func (cg *CG) Iterate(loc *Location) (Operation, error) {
 	return cg.ls.Iterate(loc)
 }
 

gradientdescent.go

@@ -18,7 +18,7 @@ type GradientDescent struct {
 	ls *LinesearchMethod
 }
 
-func (g *GradientDescent) Init(loc *Location) (RequestType, error) {
+func (g *GradientDescent) Init(loc *Location) (Operation, error) {
 	if g.StepSizer == nil {
 		g.StepSizer = &QuadraticStepSize{}
 	}
@@ -34,7 +34,7 @@ func (g *GradientDescent) Init(loc *Location) (RequestType, error) {
 	return g.ls.Init(loc)
 }
 
-func (g *GradientDescent) Iterate(loc *Location) (RequestType, error) {
+func (g *GradientDescent) Iterate(loc *Location) (Operation, error) {
 	return g.ls.Iterate(loc)
 }
 

interfaces.go

@@ -30,15 +30,15 @@ package optimize
 // combine the Evaluation operations with the Iteration operations.
 type Method interface {
 	// Init initializes the method based on the initial data in loc, updates it
-	// and returns the first request.
+	// and returns the first operation to be carried out by the caller.
 	// The initial location must be valid as specified by Needs().
-	Init(loc *Location) (RequestType, error)
+	Init(loc *Location) (Operation, error)
 
 	// Iterate retrieves data from loc, performs one iteration of the method,
-	// updates loc and returns the next request.
+	// updates loc and returns the next operation.
 	// TODO(vladimir-ch): When decided, say something whether the contents of
 	// Location is preserved between calls to Iterate().
-	Iterate(loc *Location) (RequestType, error)
+	Iterate(loc *Location) (Operation, error)
 
 	// Needs specifies information about the objective function needed by the
 	// optimizer beyond just the function value. The information is used
@@ -69,7 +69,7 @@ type Linesearcher interface {
 	// φ(0) and φ'(0), respectively, and step contains the first trial step
 	// length. It returns the type of evaluation to be performed at
 	// x_0 + step * dir_0.
-	Init(value, derivative float64, step float64) RequestType
+	Init(value, derivative float64, step float64) Operation
 
 	// Finished takes in the values of φ and φ' evaluated at the previous step,
 	// and returns whether a sufficiently accurate minimum of φ has been found.
@@ -78,7 +78,7 @@ type Linesearcher interface {
 	// Iterate takes in the values of φ and φ' evaluated at the previous step
 	// and returns the next step size and the type of evaluation to be
 	// performed at x_k + step * dir_k.
-	Iterate(value, derivative float64) (step float64, r RequestType, err error)
+	Iterate(value, derivative float64) (step float64, op Operation, err error)
 }
 
 // NextDirectioner implements a strategy for computing a new line search
@@ -109,5 +109,5 @@ type StepSizer interface {
 // the progress to StdOut or to a log file. A Recorder must not modify any data.
 type Recorder interface {
 	Init() error
-	Record(*Location, RequestType, *Stats) error
+	Record(*Location, Operation, *Stats) error
 }

lbfgs.go

@@ -38,7 +38,7 @@ type LBFGS struct {
 	rhoHist []float64   // last Store iterations of rho
 }
 
-func (l *LBFGS) Init(loc *Location) (RequestType, error) {
+func (l *LBFGS) Init(loc *Location) (Operation, error) {
 	if l.Linesearcher == nil {
 		l.Linesearcher = &Bisection{}
 	}
@@ -50,7 +50,7 @@ func (l *LBFGS) Init(loc *Location) (RequestType, error) {
 	return l.ls.Init(loc)
 }
 
-func (l *LBFGS) Iterate(loc *Location) (RequestType, error) {
+func (l *LBFGS) Iterate(loc *Location) (Operation, error) {
 	return l.ls.Iterate(loc)
 }
 

linesearch.go

@@ -24,14 +24,14 @@ type LinesearchMethod struct {
 	first     bool // Indicator of the first iteration.
 	nextMajor bool // Indicates that MajorIteration must be requested at the next call to Iterate().
 
-	loc  Location    // Storage for intermediate locations.
-	eval RequestType // Indicator of valid fields in loc.
+	loc  Location  // Storage for intermediate locations.
+	eval Operation // Indicator of valid fields in loc.
 
-	lastStep    float64     // Step taken from x in the previous call to Iterate().
-	lastRequest RequestType // Request returned from the previous call to Iterate().
+	lastStep float64   // Step taken from x in the previous call to Iterate().
+	lastOp   Operation // Operation returned from the previous call to Iterate().
 }
 
-func (ls *LinesearchMethod) Init(loc *Location) (RequestType, error) {
+func (ls *LinesearchMethod) Init(loc *Location) (Operation, error) {
 	if loc.Gradient == nil {
 		panic("linesearch: gradient is nil")
 	}
@@ -51,14 +51,14 @@ func (ls *LinesearchMethod) Init(loc *Location) (RequestType, error) {
 	}
 
 	ls.lastStep = math.NaN()
-	ls.lastRequest = NoRequest
+	ls.lastOp = NoOperation
 
 	return ls.initNextLinesearch(loc.X)
 }
 
-func (ls *LinesearchMethod) Iterate(loc *Location) (RequestType, error) {
-	switch ls.lastRequest {
-	case NoRequest:
+func (ls *LinesearchMethod) Iterate(loc *Location) (Operation, error) {
+	switch ls.lastOp {
+	case NoOperation:
 		// TODO(vladimir-ch): We have previously returned with an error and
 		// Init() was not called. What to do? What about ls's internal state?
 
@@ -69,22 +69,22 @@ func (ls *LinesearchMethod) Iterate(loc *Location) (RequestType, error) {
 		return ls.initNextLinesearch(loc.X)
 
 	default:
-		if ls.lastRequest&EvaluationRequest == 0 {
-			panic("linesearch: unexpected request")
+		if !ls.lastOp.IsEvaluation() {
+			panic("linesearch: unexpected operation")
 		}
 
 		// Store the result of the previously requested evaluation into ls.loc.
-		if ls.lastRequest&FuncEvaluation != 0 {
+		if ls.lastOp&FuncEvaluation != 0 {
 			ls.loc.F = loc.F
 		}
-		if ls.lastRequest&GradEvaluation != 0 {
+		if ls.lastOp&GradEvaluation != 0 {
 			copy(ls.loc.Gradient, loc.Gradient)
 		}
-		if ls.lastRequest&HessEvaluation != 0 {
+		if ls.lastOp&HessEvaluation != 0 {
 			ls.loc.Hessian.CopySym(loc.Hessian)
 		}
 		// Update the indicator of valid fields of ls.loc.
-		ls.eval |= ls.lastRequest
+		ls.eval |= ls.lastOp
 
 		if ls.nextMajor {
 			ls.nextMajor = false
@@ -94,26 +94,26 @@ func (ls *LinesearchMethod) Iterate(loc *Location) (RequestType, error) {
 			// can announce MajorIteration.
 
 			copyLocation(loc, &ls.loc)
-			ls.lastRequest = MajorIteration
-			return ls.lastRequest, nil
+			ls.lastOp = MajorIteration
+			return ls.lastOp, nil
 		}
 	}
 
 	projGrad := floats.Dot(ls.loc.Gradient, ls.dir)
 	if ls.Linesearcher.Finished(ls.loc.F, projGrad) {
-		// Form a request that evaluates invalid fields of ls.loc.
-		ls.lastRequest = complementEval(&ls.loc, ls.eval)
-		if ls.lastRequest == NoRequest {
+		// Form an operation that evaluates invalid fields of ls.loc.
+		ls.lastOp = complementEval(&ls.loc, ls.eval)
+		if ls.lastOp == NoOperation {
 			// ls.loc is complete and MajorIteration can be announced directly.
 			copyLocation(loc, &ls.loc)
-			ls.lastRequest = MajorIteration
+			ls.lastOp = MajorIteration
 		} else {
 			ls.nextMajor = true
 		}
-		return ls.lastRequest, nil
+		return ls.lastOp, nil
 	}
 
-	step, request, err := ls.Linesearcher.Iterate(ls.loc.F, projGrad)
+	step, op, err := ls.Linesearcher.Iterate(ls.loc.F, projGrad)
 	if err != nil {
 		return ls.error(err)
 	}
@@ -132,26 +132,26 @@ func (ls *LinesearchMethod) Iterate(loc *Location) (RequestType, error) {
 
 		ls.lastStep = step
 		copy(ls.loc.X, loc.X) // Move ls.loc to the next evaluation point
-		ls.eval = NoRequest   // and invalidate all its fields.
+		ls.eval = NoOperation // and invalidate all its fields.
 	} else {
 		// Linesearcher is requesting another evaluation at the same point
 		// which is stored in ls.loc.X.
 		copy(loc.X, ls.loc.X)
 	}
 
-	ls.lastRequest = request
-	return ls.lastRequest, nil
+	ls.lastOp = op
+	return ls.lastOp, nil
 }
 
-func (ls *LinesearchMethod) error(err error) (RequestType, error) {
-	ls.lastRequest = NoRequest
-	return ls.lastRequest, err
+func (ls *LinesearchMethod) error(err error) (Operation, error) {
+	ls.lastOp = NoOperation
+	return ls.lastOp, err
 }
 
 // initNextLinesearch initializes the next linesearch using the previous
-// complete location stored in ls.loc. It fills xNext and returns an
-// evaluation request to be performed at xNext.
-func (ls *LinesearchMethod) initNextLinesearch(xNext []float64) (RequestType, error) {
+// complete location stored in ls.loc. It fills xNext and returns an evaluation
+// to be performed at xNext.
+func (ls *LinesearchMethod) initNextLinesearch(xNext []float64) (Operation, error) {
 	copy(ls.x, ls.loc.X)
 
 	var step float64
@@ -167,7 +167,7 @@ func (ls *LinesearchMethod) initNextLinesearch(xNext []float64) (RequestType, er
 		return ls.error(ErrNonNegativeStepDirection)
 	}
 
-	ls.lastRequest = ls.Linesearcher.Init(ls.loc.F, projGrad, step)
+	ls.lastOp = ls.Linesearcher.Init(ls.loc.F, projGrad, step)
 
 	floats.AddScaledTo(xNext, ls.x, step, ls.dir)
 	if floats.Equal(ls.x, xNext) {
@@ -179,9 +179,9 @@ func (ls *LinesearchMethod) initNextLinesearch(xNext []float64) (RequestType, er
 
 	ls.lastStep = step
 	copy(ls.loc.X, xNext) // Move ls.loc to the next evaluation point
-	ls.eval = NoRequest   // and invalidate all its fields.
+	ls.eval = NoOperation // and invalidate all its fields.
 
-	return ls.lastRequest, nil
+	return ls.lastOp, nil
 }
 
 // ArmijoConditionMet returns true if the Armijo condition (aka sufficient