美文网首页
Fisher线性判别(模式识别1)

Fisher线性判别(模式识别1)

作者: 小火伴 | 来源:发表于2018-01-17 16:50 被阅读59次
    0 1 2 3

    程序

    main.py

    # %%
    import numpy as np
    from Fisher import Fisher
    import process_data as pd
    import Eval
    import time
    import os
    
    
    
    
    
    # To->main
    
    ### t0=time.time()
    # file_name = './Sonar.csv'
    file_name = './usps_3&8.csv'
    
    cross_validation_number = 10
    class_number = 2
    
    
    # dataset = dict()
    
    def main():
        data = dict(x=[[], []], y=[[], []])
        val_data = dict(x=[[], []], y=[[], []])
        Pred_True = [0] * class_number
        pred_num=[0,0]
        L = [0, 0]
        last_j=float('-inf')
    
        datas, L[0], L[1], Lall = pd.read_datas(file_name)
        data_block = pd.split_datas(datas, cross_validation_number)
        # i = 0
        for cla, val in data_block:
            # print(i)
            # i += 1
            for j in range(len(cla)):
                (data['x'][j], data['y'][j], val_data['x'][j], val_data['y'][j]) = (
                cla[j][:, :-1], cla[j][:, -1:], val[j][:, :-1], val[j][:, -1:])
            myfisher = Fisher(L[0], L[1], Lall, data)
    
            W = myfisher.W_Direction()  # 投影参数
            J=Eval.simple_Fisher_Friterion(W,myfisher.between_class_scatter_matrix())#评估一下投影效果,并更新投影向量
            if J>last_j:
                last_j=J
                W_great=W
            W0 = myfisher.OneKey_W0(W)  # 阈值
            # %%
            for j in range(class_number):
                predict_y = myfisher.Pred_result(W, val_data['x'][j], W0)
                # print(predict_y)
                pred_num[j]+=len(val_data['x'][j])
                Pred_True[j] += Eval.Comp_as1(predict_y, val_data['y'][j][0][0])
                # if j==1:
                #     print(Eval.Comp_as1(predict_y, val_data['y'][j][0][0]))
    
                # print(W,W0)
                # print(S_W)
                # print(time.time()-t0)
                # break
        print('  预测      第1类   第2类   全部')
        for j in range(class_number):
            print('实际第{0}类    {1}     {2}      {3}'.format(j+1,Pred_True[j],pred_num[j]-Pred_True[j],pred_num[j]))
        print('mixed_accuracy:%f' % ((Pred_True[0]+pred_num[1]-Pred_True[1])/(pred_num[0]+pred_num[1])))
    
        # print(os.path.isfile(Eval.w_filename),W_great)
        # if os.path.isfile(Eval.w_filename)==False and W_great:
        print('评价函数最大的W保存在',os.path.abspath(Eval.w_filename))
        Eval.save_par(W_great)
        pass
    
    
    if __name__ == '__main__':
        main()
    
    '''
    sonar
      预测      第1类   第2类   全部
    实际第1类    63     33      96
    实际第2类    36     72      108
    mixed_accuracy:0.661765
    
    usps_3&8
      预测      第1类   第2类   全部
    实际第1类    789     31      820
    实际第2类    20     680      700
    mixed_accuracy:0.966447
    '''
    

    Fisher.py

    import numpy as np
    
    x = []  # n*d
    w = []  # d*1
    y = []  # 0*n
    
    x = np.array(x)
    w = np.array(w)
    y = np.array(y)
    
    
    def within_class_scatter_matrix(x, m):
        '''
    
        :param x: n*d->n*d*1
        :param m: d*1->1*d*1
        :return:类內离散度矩阵 d*d
        '''
        x = x[:, :, np.newaxis]
        m_d = len(m)
        m = m[np.newaxis, :, :]  # 1*d*1
        n, d = np.shape(x)[0], np.shape(x)[1]
        assert d == m_d
        temp = x - m
        temp_tran = np.transpose(temp, (0, 2, 1))  # n*1*d
        # print(list(map(np.shape,[x-m,x_transpose-m_transpose])))
        # 三维点乘变循环
        s = []
        for a, b in zip(temp, temp_tran):
            s.append(np.dot(a, b))
        s = np.array(s)
        s = np.sum(s, 0)
        assert s.shape == (d, d)
        return s
    
    
    def pooled_within_class_scatter_matrix(wcsm1, wcsm2, L1, L2, Lall):
        '''
    
        :param wcsm1: d*d
        :param wcsm2:
        :return: 总类內离散度矩阵 d*d
        '''
        return (L1 * wcsm1 + L2 * wcsm2) / Lall
    
    def projective_mean(w, m):
        '''
    
        :param w: 投影方向 d*1
        :param m: 类均值向量 d*1
        :return:投影后的均值 0*0 scalar
        '''
    
        def pred_y(x, w):
            '''
            :param x: n*d
            :param w: d*1
            :return: 预测值 0*n
            '''
            return x.dot(w).ravel()
    
        assert np.shape(w) == np.shape(m)
        # print('w:',np.transpose(w).shape,'m',m.shape)
        # print(pred_y(np.transpose(w),m)[0])
        return pred_y(np.transpose(w), m)[0]
    
    
    def projective_within_class_scatter_matrix(y, M):
        '''
    
        :param y: 投影后的样本0*n
        :param M: 均值向量投影后 0*0
        :return:投影后类內离散度0*0 scalar
        '''
        M = np.array([M])  # 0*1
        return pow(np.linalg.norm(y - M), 2)
    
    
    def projective_between_class_scatter_matrix(m1, m2):
        '''
    
        :param m1: 投影后均值
        :param m2:
        :return: 投影后类间离散度0*0 scalar
        '''
        return pow((m1 - m2), 2)
    
    
    def w_direction(S_W, m1, m2):
        '''
    
        :param S_W:总类內离散度矩阵 d*d
        :param m1: 类均值向量 d*1
        :param m2:
        :return: d*1 投影参数(大小无所谓)
        '''
        # print(S_W**-1)
        # print()
        return np.dot(np.linalg.inv(S_W), (m1 - m2))
    
    
    def W0(m1, m2):
        '''
        不考虑先验概率
        :param m1: scalar 投影后均值
        :param m2:
        :return: 阈值
        '''
        return -(m1 + m2) / 2
    
    class Fisher(object):
        def __init__(self, L1, L2, Lall, data):
            self.L1 = L1
            self.L2 = L2
            self.Lall = Lall
            self.M = [[], []]  # 均值向量
            self.M[0], self.M[1] = map(self.__class_mean_vector, [data['x'][0], data['x'][1]])
            self.data_x=data['x']
    
        def __class_mean_vector(self, x):
            '''
    
            :param x:n*d
            :return:类均值向量 d*1
            '''
            return np.transpose(np.mean(x, 0, keepdims=True))
    
        def Pred_result(self, w, x, w0):
            '''
    
            :param w:投影参数d*1
            :param x: n*d
            :param w0: 0*0
            :return: 决策结果 (n,)
            '''
            w0 = np.array([w0])
            temp = np.dot(x, w)
            return temp.ravel() + w0
    
        def W_Direction(self):
            Sw1, Sw2 = within_class_scatter_matrix(self.data_x[0], self.M[0]), within_class_scatter_matrix(self.data_x[1], self.M[1])
            SW = pooled_within_class_scatter_matrix(Sw1, Sw2, self.L1, self.L2, self.Lall)
            W = w_direction(SW, self.M[0], self.M[1])
            return W
    
        def OneKey_W0(self, W):
            m1, m2 = projective_mean(W, self.M[0]), projective_mean(W, self.M[1])
            return W0(m1, m2)
    
        def between_class_scatter_matrix(self):
            '''
    
            :param m1: 第一类均值向量 d*1
            :param m2: 第二类均值向量
            :return: 类间离散度矩阵 d*d
            '''
            m_ = self.M[0] - self.M[1]
    
            return np.dot(m_, np.transpose(m_))
    
    

    Eval.py

    import json
    import numpy as np
    
    
    #To->Eval
    w_filename='w.json'
    
    def save_par(w):
        with open(w_filename,'w') as fp:
            json.dump(list(w.ravel()),fp)
    
    def load_par():
        with open(w_filename,'r') as fp:
            return np.array(json.load(fp))[:,np.newaxis]
    
    def Comp_as1(y):
        # y=(y>0.0 if label>0 else y<=0.0)
        y= y>0.0
        return np.sum(y)
    
    def simple_Fisher_Friterion(w,S_b):
        '''
        Fisher简化版的判别函数
        :param w: 投影向量d*1
        :param S_b: 类间离散度矩阵
        :return:
        '''
        return np.dot(np.dot(np.transpose(w),S_b),w)[0][0]
    

    process_data.py

    import logging
    import numpy as np
    import random
    
    #%%
    # To->process_data
    ## ---sonar
    # label=('R','M')
    # file_size=(208,61)
    # label_dict={label[0]:1,label[1]:-1}
    ## ---usps
    label=('3','8')
    file_size=(9298,257)
    label_dict={label[0]:3,label[1]:8}
    
    def save_38(data):
        import csv
        with open('usps_3&8.csv','w',newline='') as csvfile:
            writer=csv.writer(csvfile)
            writer.writerows(data)
            print('写完了')
            exit(0)
    
    def read_datas(file_name):
        '''
        读取并处理文件
        :param file_name:
        :return:
        '''
        datas1,datas2=[],[]
        with open(file_name,'r') as f:
            datas=f.readlines()
        #%%
        for i in range(len(datas)):
            datas[i]=datas[i][:-1]
            datas[i]=datas[i].split(',')
            # print(i)
            datas[i][:-1]=list(map(float,datas[i][:-1]))
            # print(datas[i][-1])
            # try:
            datas[i][-1]=label_dict[datas[i][-1]]#替换成数字
            # except KeyError:
            #     continue
        # print('数据大小',np.array(datas).shape)
        # assert np.array(datas).shape==file_size
        # 可以用转成数组处理
        for data in datas:
            # print(data[-1])
            #分别添加到两个数据
            if data[-1]==label_dict[label[0]]:
                datas1.append(data)
            elif data[-1]==label_dict[label[1]]:
                datas2.append(data)
            else:
                # continue
                print('这个标签 %s 未知,请看一下,在第%d行' % (data[-1],datas.index(data)))
        # 可以用转成数组处理
        #随机一下顺序
        # save_38(datas1+datas2)
        map(random.shuffle,[datas1,datas2])
        L1,L2,Lall=len(datas1),len(datas2),file_size[0]
        # assert (L1+L2)==Lall
        print('——————数据读取完成!——————')
        return ((datas1,datas2),L1,L2,Lall)
    #%%
    def split_datas(datas,n):
        '''
        验证集和训练集分开
        :param n: n折交叉验证
        :param datas: 打乱后的数据,
        :return: 若n=10,第一类,第二类,交叉验证集20*61
        '''
        data_block_len=[len(data)//n for data in datas]
        for i in range(n):
            val,cla=[],[]
            for j,data in enumerate(datas):
                val_left,val_right=data_block_len[j]*(i),data_block_len[j]*(i+1)
                val.append(np.array(data[val_left:val_right]))
                cla.append(np.array(data[:val_left]+data[val_right:]))
            yield cla,val
    

    相关文章

      网友评论

          本文标题:Fisher线性判别(模式识别1)

          本文链接:https://www.haomeiwen.com/subject/efbyoxtx.html