forked from projectcalico/felix
-
Notifications
You must be signed in to change notification settings - Fork 0
/
least_squares_method.go
48 lines (39 loc) · 1.28 KB
/
least_squares_method.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
// Copyright (c) 2017 Tigera, Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Code copied from https://gist.github.com/ota42y/db4ff0298d9c945cd261, with some modifications.
package leastsquares
type Point struct {
X float64
Y float64
}
func LeastSquaresMethod(points []Point) (a float64, b float64) {
// Calculate a and b such that y = ax + b is the best fit to the given points.
//
// http://ja.wikipedia.org/wiki/%E6%9C%80%E5%B0%8F%E4%BA%8C%E4%B9%97%E6%B3%95
n := float64(len(points))
sumX := 0.0
sumY := 0.0
sumXY := 0.0
sumXX := 0.0
for _, p := range points {
sumX += p.X
sumY += p.Y
sumXY += p.X * p.Y
sumXX += p.X * p.X
}
base := (n*sumXX - sumX*sumX)
a = (n*sumXY - sumX*sumY) / base
b = (sumXX*sumY - sumXY*sumX) / base
return a, b
}