From 1cae4ca316afa5d177fdbf7a98a0ec7fffe76a3e Mon Sep 17 00:00:00 2001
From: Shulhan <ms@kilabit.info>
Date: Mon, 17 Sep 2018 05:04:26 +0700
Subject: Merge package "github.com/shuLhan/go-mining"

---
 lib/mining/classifier/stats_interface.go | 68 ++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 lib/mining/classifier/stats_interface.go

(limited to 'lib/mining/classifier/stats_interface.go')

diff --git a/lib/mining/classifier/stats_interface.go b/lib/mining/classifier/stats_interface.go
new file mode 100644
index 00000000..a9b60b9a
--- /dev/null
+++ b/lib/mining/classifier/stats_interface.go
@@ -0,0 +1,68 @@
+// Copyright 2016 Mhd Sulhan <ms@kilabit.info>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package classifier
+
+//
+// ComputeFMeasures given array of precisions and recalls, compute F-measure
+// of each instance and return it.
+//
+func ComputeFMeasures(precisions, recalls []float64) (fmeasures []float64) {
+	// Get the minimum length of precision and recall.
+	// This is to make sure that we are not looping out of range.
+	minlen := len(precisions)
+	recallslen := len(recalls)
+	if recallslen < minlen {
+		minlen = recallslen
+	}
+
+	for x := 0; x < minlen; x++ {
+		f := 2 / ((1 / precisions[x]) + (1 / recalls[x]))
+		fmeasures = append(fmeasures, f)
+	}
+	return
+}
+
+//
+// ComputeAccuracies will compute and return accuracy from array of
+// true-positive, false-positive, true-negative, and false-negative; using
+// formula,
+//
+//	(tp + tn) / (tp + tn + tn + fn)
+//
+func ComputeAccuracies(tp, fp, tn, fn []int64) (accuracies []float64) {
+	// Get minimum length of input, just to make sure we are not looping
+	// out of range.
+	minlen := len(tp)
+	if len(fp) < len(tn) {
+		minlen = len(fp)
+	}
+	if len(fn) < minlen {
+		minlen = len(fn)
+	}
+
+	for x := 0; x < minlen; x++ {
+		acc := float64(tp[x]+tn[x]) /
+			float64(tp[x]+fp[x]+tn[x]+fn[x])
+		accuracies = append(accuracies, acc)
+	}
+	return
+}
+
+//
+// ComputeElapsedTimes will compute and return elapsed time between `start`
+// and `end` timestamps.
+//
+func ComputeElapsedTimes(start, end []int64) (elaps []int64) {
+	// Get minimum length.
+	minlen := len(start)
+	if len(end) < minlen {
+		minlen = len(end)
+	}
+
+	for x := 0; x < minlen; x++ {
+		elaps = append(elaps, end[x]-start[x])
+	}
+	return
+}
-- 
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