cluster.py

import os
import arff
import math
import numpy as np
import random
def second(a):
    return a[1]
files = []
data_path = "MDP\\D''\\"
target_path = "MDP\\D-cb\\"
for f in os.listdir(data_path):
    files.append(f)
for f in range(len(files)):
    print(f, end="...")
    f_path = os.path.join(data_path, files[f])
    inst = list(arff.load(f_path))
    majority = []
    minority = []
    for i in inst:
        i = list(i)
        if i[-1]=='N':
            majority.append(i)
        else:
            minority.append(i)
    k = len(majority)//len(minority)
    synthetic = []
    safe = []
    for i in range(len(minority)):
        x = minority[i][:-1]
        nn = []
        for j in range(len(inst)):
            z = list(inst[j])[:-1]
            dist = math.sqrt(sum([(x[l]-z[l])**2 for l in range(len(x))]))
            if dist != 0:
                nn.append((list(inst[j]), dist))
        knn = sorted(nn, key=second)[:k]
        new = [a[0] for a in knn]
        m = 0
        for a in new:
            if a[-1]=='N':
                m+=1
        if m<(k/2):
            safe.append(minority[i])
    for i in range(len(safe)):
        x = safe[i][:-1]
        nn = []
        for j in range(len(safe)):
            if i != j:
                z = safe[j][:-1]
                dist = math.sqrt(sum([(x[l]-z[l])**2 for l in range(len(x))]))
                nn.append((safe[j], dist))
        knn = sorted(nn, key=second)[:k]
        new = [a[0] for a in knn]
        r = random.random()
        while r==0 or r==1:
            r = random.random()
        for j in range(len(new)):
            temp = [x[l]+r*abs(x[l]-new[j][l]) for l in range(len(new[j])-1)]
            temp.append(new[j][-1])
            synthetic.append(temp)
    for i in synthetic:
        inst.append(i)
    path = os.path.join(target_path, files[f])
    arff.dump(path, inst, relation=files[f][:-5])
    print('done')