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mirror of https://github.com/sjwhitworth/golearn.git synced 2025-04-28 13:48:56 +08:00

Tidying up

This commit is contained in:
Stephen Whitworth 2013-12-29 00:03:42 +00:00
parent cc69c1ab2f
commit 4e81045015
5 changed files with 4 additions and 186 deletions

53
base.go
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@ -1,53 +0,0 @@
package base
import (
"os"
"encoding/csv"
"fmt"
"io"
"strconv"
)
func ParseCsv(filepath string, text int, columns []int) (int, int,[]string, []string, []float64) {
labels := make([]string, 10)
data := make([]float64, 10)
headers := make([]string, 2)
rows := 0
file, err := os.Open(filepath)
if err != nil {
fmt.Println("Error:", err)
}
defer file.Close()
reader := csv.NewReader(file)
headerrow, _ := reader.Read()
for _, col := range columns {
entry := headerrow[col]
headers = append(headers, entry)
}
for {
record, err := reader.Read()
if err == io.EOF {
break
} else if err != nil {
fmt.Println("Error:", err)
}
//
labels = append(labels, record[text])
//Iterate over our rows and append the values to a slice
for _, col := range columns {
entry := record[col]
number, _ := strconv.ParseFloat(entry, 64)
data = append(data, number)
}
rows += 1
}
cols := len(columns)
return cols, rows, headers, labels, data
}

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@ -1,4 +1,4 @@
package base
package golearn
import (
"os"
@ -8,8 +8,8 @@ import (
"strconv"
)
//Need to implement base functions here, like parsing CSV etc.
//Parses a CSV file, returning the number of columns and rows, the headers, the labels associated with
//classification, and the data that will be used for training.
func ParseCsv(filepath string, text int, columns []int) (int, int,[]string, []string, []float64) {
labels := make([]string, 10)
data := make([]float64, 10)

129
knn.go
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@ -1,129 +0,0 @@
package main
import (
mat "github.com/skelterjohn/go.matrix"
rand "math/rand"
"math"
"fmt"
"sort"
"/base/"
// "errors"
)
//Sorts a map by value size in .s property
type sortedMap struct {
m map[int]float64
s []int
}
func (sm *sortedMap) Len() int {
return len(sm.m)
}
func (sm *sortedMap) Less(i, j int) bool {
return sm.m[sm.s[i]] < sm.m[sm.s[j]]
}
func (sm *sortedMap) Swap(i, j int) {
sm.s[i], sm.s[j] = sm.s[j], sm.s[i]
}
func sortMap(m map[int]float64) []int {
sm := new(sortedMap)
sm.m = m
sm.s = make([]int, len(m))
i := 0
for key, _ := range m {
sm.s[i] = key
i++
}
sort.Sort(sm)
return sm.s
}
type KNNClassifier struct {
Data mat.DenseMatrix
Name string
Labels []string
}
func RandomArray(n int) []float64 {
ReturnedArray := make([]float64, n)
for i := 0; i < n; i++ {
ReturnedArray[i] = rand.Float64()
}
return ReturnedArray
}
//Mints a new classifier
func (KNN *KNNClassifier) New(name string, labels []string, numbers []float64, x int, y int) {
// if x != len(KNN.Labels) {
// return errors.New("KNN: There must be a label for each row")
// }
KNN.Data = *mat.MakeDenseMatrix(numbers, x, y)
KNN.Name = name
KNN.Labels = labels
}
//Computes a variety of distance metrics between two vectors
//Only returns Euclidean distance at the moment
func (KNN *KNNClassifier) ComputeDistance(vector *mat.DenseMatrix, testrow *mat.DenseMatrix) float64 {
var sum float64
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
}
//Returns a classification based on a vector input
//Just need to build the max voting function
func (KNN *KNNClassifier) Predict(vector *mat.DenseMatrix, K int) ([]string, []int) {
rows := KNN.Data.Rows()
rownumbers := make(map[int]float64)
labels := make([]string, K)
for i := 0; i < rows; i++{
row := KNN.Data.GetRowVector(i)
eucdistance := KNN.ComputeDistance(row, vector)
rownumbers[i] = eucdistance
}
sorted := sortMap(rownumbers)
values := sorted[:K]
for _, elem := range values {
labels = append(labels, KNN.Labels[elem])
}
return labels, values
}
//Returns a label, given an index
func (KNN *KNNClassifier) GetLabel(index int) string {
return KNN.Labels[index]
}
func main(){
for {
cols, rows, _, labels, data := base.ParseCsv("/Users/stephenwhitworth/Desktop/model.csv", 1, []int{2,3})
knn := KNNClassifier{}
random := mat.MakeDenseMatrix([]float64{410,433,400,400},1,2)
knn.New("Testing", labels, data, rows, cols)
labels, indexes := knn.Predict(random, 1)
fmt.Println(labels, indexes)
}
}

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@ -1,4 +1,4 @@
package main
package golearn
import (
mat "github.com/skelterjohn/go.matrix"