We will need to implement many metrics, so we should split it into a package.

examples/metrics/metrics.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"fmt"
+
+	pariwiseMetrics "github.com/sjwhitworth/golearn/metrics/pairwise"
+	"github.com/sjwhitworth/golearn/utilities"
+	mat "github.com/skelterjohn/go.matrix"
+)
+
+func main() {
+	randArray := utilities.RandomArray(3, 7)
+	vectorX := mat.MakeDenseMatrix(randArray, 1, 3)
+	randArray = utilities.RandomArray(3, 7)
+	vectorY := mat.MakeDenseMatrix(randArray, 1, 3)
+
+	distance, err := pariwiseMetrics.Euclidean(vectorX, vectorY)
+
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	fmt.Println("Euclidean distance of " + vectorX.String() + " and " + vectorY.String() + " is: ")
+	fmt.Println(distance)
+}

metrics/pairwise/euclidean.go

@@ -0,0 +1,30 @@
+package pairwise
+
+import (
+	"fmt"
+	"math"
+
+	mat "github.com/skelterjohn/go.matrix"
+)
+
+// We may need to create Metrics / Vector interface for this
+func Euclidean(vectorX *mat.DenseMatrix, vectorY *mat.DenseMatrix) (float64, error) {
+	var sum float64
+
+	difference, err := vectorY.MinusDense(vectorX)
+
+	flat := difference.Array()
+
+	if err != nil {
+		fmt.Println(err)
+		return -1, err
+	}
+
+	for _, i := range flat {
+		squared := math.Pow(i, 2)
+		sum += squared
+	}
+
+	distance := math.Sqrt(sum)
+	return distance, nil
+}

utilities/distance.go

@@ -1,36 +0,0 @@
-package utilities
-
-import (
-	"fmt"
-	"math"
-
-	mat "github.com/skelterjohn/go.matrix"
-)
-
-// Computes the 'distance' between two vectors, where the distance is one of the following methods -
-// euclidean (more to come)
-func ComputeDistance(metric string, vector *mat.DenseMatrix, testrow *mat.DenseMatrix) (float64, error) {
-	var sum float64
-
-	switch metric {
-	case "euclidean":
-		{
-			difference, err := testrow.MinusDense(vector)
-			flat := difference.Array()
-
-			if err != nil {
-				fmt.Println(err)
-			}
-
-			for _, i := range flat {
-				squared := math.Pow(i, 2)
-				sum += squared
-			}
-
-			eucdistance := math.Sqrt(sum)
-			return eucdistance, nil
-		}
-	default:
-		return 0.0, fmt.Errorf("ValueError: %s is not an implemented distance method", metric)
-	}
-}