Add FullRecorder for logging an entire optimization

printer.go → recorder.go

@@ -5,6 +5,7 @@
 package optimize
 
 import (
+	"encoding/json"
 	"fmt"
 	"io"
 	"math"
@@ -104,3 +105,72 @@ func (p *Printer) Record(loc *Location, op Operation, stats *Stats) error {
 	p.lastValue = time.Now()
 	return nil
 }
+
+// Full Recorder records all of the evaluations that occur during an optimization
+// run. If Operation is an Evaulation, FullRecorder records the x location and
+// the corresponding field of Location. If Operation is a MajorIteration, or
+// PostIteration, FullRecorder records the full value of the Location struct.
+// Otherwise, FullRecorder records the operation type.
+type FullRecorder struct {
+	Writer io.Writer
+}
+
+func (f FullRecorder) Init() error {
+	return nil
+}
+
+func (f FullRecorder) Record(loc *Location, op Operation, stats *Stats) error {
+	r := RecordLocation{Op: op.String()}
+	switch {
+	case op.isEvaluation():
+		r.Loc.X = loc.X
+		switch op {
+		default:
+			panic("optimize: unknown evaluation operation")
+		case FuncEvaluation:
+			r.Loc.F = loc.F
+		case GradEvaluation:
+			r.Loc.Gradient = loc.Gradient
+		case HessEvaluation:
+			r.Loc.Hessian = loc.Hessian
+		}
+	case op == MajorIteration || op == PostIteration:
+		r.Loc = *loc
+	}
+	if op.isEvaluation() {
+
+	} else if op == MajorIteration {
+
+	}
+	b, err := json.MarshalIndent(r, "", "\t")
+	if err != nil {
+		return nil
+	}
+	_, err = f.Writer.Write(b)
+	return err
+}
+
+// Read reads the stream written to by FullRecorder, and returns the history of
+// the optimization run.
+func (f FullRecorder) Read(r io.Reader) ([]RecordLocation, error) {
+	d := json.NewDecoder(r)
+	var records []RecordLocation
+	var err error
+	for {
+		var r RecordLocation
+		err = d.Decode(&r)
+		if err != nil {
+			break
+		}
+		records = append(records, r)
+	}
+	if err == io.EOF {
+		return records, nil
+	}
+	return records, err
+}
+
+type RecordLocation struct {
+	Op  string
+	Loc Location
+}