返回顶部
首页 > 资讯 > 后端开发 > Python >时间序列模型SCINet(代码解析)
  • 766
分享到

时间序列模型SCINet(代码解析)

人工智能pythonSCINet时间序列预测因果神经网络 2023-09-10 10:09:22 766人浏览 安东尼

Python 官方文档:入门教程 => 点击学习

摘要

前言 SCINet模型,精度仅次于NLinear的时间序列模型,在ETTh2数据集上单变量预测结果甚至比NLinear模型还要好。在这里还是建议大家去读一读论文,论文写的很规范,很值得学习,论文地址S

前言

  • SCINet模型,精度仅次于NLinear的时间序列模型,在ETTh2数据集上单变量预测结果甚至比NLinear模型还要好。
  • 在这里还是建议大家去读一读论文,论文写的很规范,很值得学习论文地址
  • SCINet模型Github项目地址,下载项目文件,需要注意的是该项目仅支持在GPU上运行,如果没有GPU会报错。
  • 关于该模型的理论部分,本来准备自己写的,但是看到已经有很多很优秀的帖子了,这里给大家推荐几篇:
  • SCINet学习记录中有一副思维导图画的很好,这里搬运过来方便大家在阅读代码时对照模型架构
    请添加图片描述
  • 由于理论部分已经有了,这里我仅对项目中各代码以及框架做注释说明,方便大家理解代码,后面如果有需要,可以再写一篇,对于自定义数据如何使用SCINet模型。

参数设定模块(run_ETTh)

  • 因为作者在做对比实验时用了很多公共数据集,所以文件夹中有run_ETTh.pyrun_financial.pyrun_pems.py3个文件,分别对应3大主要公共数据集,这里选用ETTh数据集作为示范。所以首先打开run_ETTh.py文件
  • ETTh数据集需要自行下载,如果是在linux系统中可以直接运行项目文件下prepare_data.sh文件,下载全部数据集。如果是win系统,则需要自己下载.csv文件,并在项目文件夹下创建datasets文件夹,并将数据放入该文件夹。
  • 我下载了ETTh1.csv文件,后面的示范均在该数据集上进行

参数含义

下面是各参数含义(注释)

# 模型名称parser.add_argument('--model', type=str, required=False, default='SCINet', help='model of the experiment')### -------  dataset settings --------------# 数据名称parser.add_argument('--data', type=str, required=False, default='ETTh1', choices=['ETTh1', 'ETTh2', 'ETTm1'], help='name of dataset')# 数据路径parser.add_argument('--root_path', type=str, default='./datasets/', help='root path of the data file')# 数据文件parser.add_argument('--data_path', type=str, default='ETTh1.csv', help='location of the data file')# 预测方式(S:单变量预测,M:多变量预测)parser.add_argument('--features', type=str, default='M', choices=['S', 'M'], help='features S is univariate, M is multivariate')# 需要预测列的列名parser.add_argument('--target', type=str, default='OT', help='target feature')# 时间采样格式parser.add_argument('--freq', type=str, default='h', help='freq for time features encoding, options:[s:secondly, t:minutely, h:hourly, d:daily, b:business days, w:weekly, m:monthly], you can also use more detailed freq like 15min or 3h')# 模型存储路径parser.add_argument('--checkpoints', type=str, default='exp/ETT_checkpoints/', help='location of model checkpoints')# 是否翻转序列parser.add_argument('--inverse', type=bool, default =False, help='denORM the output data')# 时间特征编码方式parser.add_argument('--embed', type=str, default='timeF', help='time features encoding, options:[timeF, fixed, learned]')### -------  device settings --------------# 是否使用GPU(实测这个参数并没什么作用,即使填写False也无法使用CPU训练模型)parser.add_argument('--use_gpu', type=bool, default=True, help='use gpu')# 使用GPU设备IDparser.add_argument('--gpu', type=int, default=0, help='gpu')# 是否多GPU并行parser.add_argument('--use_multi_gpu', action='store_true', help='use multiple gpus', default=False)# 选用GPU设备IDparser.add_argument('--devices', type=str, default='0',help='device ids of multile gpus')                          ### -------  input/output length settings --------------# 回视窗口大小parser.add_argument('--seq_len', type=int, default=96, help='input sequence length of SCINet encoder, look back window')# 先验窗口大小parser.add_argument('--label_len', type=int, default=48, help='start token length of Informer decoder')# 需要预测序列长度parser.add_argument('--pred_len', type=int, default=48, help='prediction sequence length, horizon')# 丢弃数据长度parser.add_argument('--concat_len', type=int, default=0)parser.add_argument('--single_step', type=int, default=0)parser.add_argument('--single_step_output_One', type=int, default=0)# 最后一层损失权重parser.add_argument('--lastWeight', type=float, default=1.0)      ### -------  training settings --------------# 多文件并列parser.add_argument('--cols', type=str, nargs='+', help='file list')# 多线程训练(win系统下该参数置0)parser.add_argument('--num_workers', type=int, default=0, help='data loader num workers')# 实验次数parser.add_argument('--itr', type=int, default=0, help='experiments times')# 训练迭代次数parser.add_argument('--train_epochs', type=int, default=100, help='train epochs')# mini_batch_sizeparser.add_argument('--batch_size', type=int, default=32, help='batch size of train input data')# 早停策略检测轮数parser.add_argument('--patience', type=int, default=5, help='early stopping patience')# 学习率parser.add_argument('--lr', type=float, default=0.0001, help='optimizer learning rate')# 损失函数parser.add_argument('--loss', type=str, default='mae',help='loss function')# 学习率更新策略parser.add_argument('--lradj', type=int, default=1,help='adjust learning rate')# 是否使用半精度加快训练速度parser.add_argument('--use_amp', action='store_true', help='use automatic mixed precision training', default=False)# 是否保存结果(如果你想要保存预测结果,请将该参数改为True)parser.add_argument('--save', type=bool, default =False, help='save the output results')# 模型名称parser.add_argument('--model_name', type=str, default='SCINet')# 是否断续训练parser.add_argument('--resume', type=bool, default=False)# 是否评估模型parser.add_argument('--evaluate', type=bool, default=False)### -------  model settings --------------# 隐藏通道数parser.add_argument('--hidden-size', default=1, type=float, help='hidden channel of module')# 使用交互学习或基本学习策略parser.add_argument('--INN', default=1, type=int, help='use INN or basic strategy')# kernel sizeparser.add_argument('--kernel', default=5, type=int, help='kernel size, 3, 5, 7')# 是否扩张parser.add_argument('--dilation', default=1, type=int, help='dilation')# 回视窗口parser.add_argument('--window_size', default=12, type=int, help='input size')# dropout率parser.add_argument('--dropout', type=float, default=0.5, help='dropout')# 位置编码parser.add_argument('--positionalEcoding', type=bool, default=False)parser.add_argument('--groups', type=int, default=1)# SCINet blockparser.add_argument('--levels', type=int, default=3)# SCINet blocks层数parser.add_argument('--stacks', type=int, default=1, help='1 stack or 2 stacks')# 解码器层数parser.add_argument('--num_decoder_layer', type=int, default=1)parser.add_argument('--RIN', type=bool, default=False)parser.add_argument('--decompose', type=bool,default=False)

数据文件参数

data_parser = {# data:数据文件名,T:预测列列名,M(多变量预测),S(单变量预测),MS(多特征预测单变量)    'ETTh1': {'data': 'ETTh1.csv', 'T': 'OT', 'M': [7, 7, 7], 'S': [1, 1, 1], 'MS': [7, 7, 1]},    'ETTh2': {'data': 'ETTh2.csv', 'T': 'OT', 'M': [7, 7, 7], 'S': [1, 1, 1], 'MS': [7, 7, 1]},    'ETTm1': {'data': 'ETTm1.csv', 'T': 'OT', 'M': [7, 7, 7], 'S': [1, 1, 1], 'MS': [7, 7, 1]},    'ETTm2': {'data': 'ETTm2.csv', 'T': 'OT', 'M': [7, 7, 7], 'S': [1, 1, 1], 'MS': [7, 7, 1]},    'WTH': {'data': 'WTH.csv', 'T': 'WetBulbCelsius', 'M': [12, 12, 12], 'S': [1, 1, 1], 'MS': [12, 12, 1]},    'ECL': {'data': 'ECL.csv', 'T': 'MT_320', 'M': [321, 321, 321], 'S': [1, 1, 1], 'MS': [321, 321, 1]},    'Solar': {'data': 'solar_AL.csv', 'T': 'POWER_136', 'M': [137, 137, 137], 'S': [1, 1, 1], 'MS': [137, 137, 1]},}
  • 下面是模型训练函数,这里不进行注释了

数据处理模块(etth_data_loader)

  • run_ETTh.py文件中exp.train(setting)train方法进入exp_ETTh.py文件,在_get_data中找到ETTh1数据处理方法
data_dict = {'ETTh1':Dataset_ETT_hour,             'ETTh2':Dataset_ETT_hour,             'ETTm1':Dataset_ETT_minute,             'ETTm2':Dataset_ETT_minute,             'WTH':Dataset_Custom,             'ECL':Dataset_Custom,             'Solar':Dataset_Custom,}
  • 可以看到ETTh1数据处理方法为Dataset_ETT_hour,我们进入etth_data_loader.py文件,找到Dataset_ETT_hour
  • __init__主要用于传各类参数,这里不过多赘述,主要对__read_data____getitem__进行说明
    def __read_data__(self):        # 实例化归一化        self.scaler = StandardScaler()        # 读取CSV文件        df_raw = pd.read_csv(os.path.join(self.root_path,              self.data_path))        # [0,训练序列长度-回视窗口,全部序列长度-测试序列长度-回视窗口]        border1s = [0, 12*30*24 - self.seq_len, 12*30*24+4*30*24 - self.seq_len]        # [训练序列长度,全部序列长度-测试序列长度,全部序列长度]        border2s = [12*30*24, 12*30*24+4*30*24, 12*30*24+8*30*24]        # train:[0,训练数据长度]        # val:[训练序列长度-回视窗口,全部序列长度-测试序列长度]        # test:[全部序列长度-测试序列长度-回视窗口,全部序列长度]        border1 = border1s[self.set_type]        border2 = border2s[self.set_type]        # 若采用多变量预测(M或MS)        if self.features=='M' or self.features=='MS':            # 取出特征列列名            cols_data = df_raw.columns[1:]            # 取出特征列            df_data = df_raw[cols_data]        # 若采用单变量预测        elif self.features=='S':            # 取出预测列            df_data = df_raw[[self.target]]        # 若需要进行归一化        if self.scale:            # 取出[0,训练序列长度]区间数据            train_data = df_data[border1s[0]:border2s[0]]            # 归一化            self.scaler.fit(train_data.values)            data = self.scaler.transform(df_data.values)            # data = self.scaler.fit_transform(df_data.values)        # 否则将预测列变为数组        else:            data = df_data.values        # 取对应区间时间列        df_stamp = df_raw[['date']][border1:border2]        # 将时间转换为标准格式        df_stamp['date'] = pd.to_datetime(df_stamp.date)        # 构建时间特征        data_stamp = time_features(df_stamp, timeenc=self.timeenc, freq=self.freq)        # 取对应数据区间(train、val、test)        self.data_x = data[border1:border2]        # 如果需要翻转时间序列        if self.inverse:            self.data_y = df_data.values[border1:border2]        # 否则取数据区间(train、val、test)        else:            self.data_y = data[border1:border2]        self.data_stamp = data_stamp
  • 需要注意的是time_features函数,用来提取日期特征,比如't':['month','day','weekday','hour','minute'],表示提月,天,周,小时,分钟。可以打开timefeatures.py文件进行查阅
  • 同样的,对__getitem__进行说明
    def __getitem__(self, index):        # 起点        s_begin = index        # 终点(起点 + 回视窗口)        s_end = s_begin + self.seq_len        # (终点 - 先验序列窗口)        r_begin = s_end - self.label_len        # (终点 + 预测序列长度)        r_end = r_begin + self.label_len + self.pred_len        # seq_x = [起点,起点 + 回视窗口]        seq_x = self.data_x[s_begin:s_end]  # 0 - 24        # seq_y = [终点 - 先验序列窗口,终点 + 预测序列长度]        seq_y = self.data_y[r_begin:r_end] # 0 - 48        # 取对应时间特征        seq_x_mark = self.data_stamp[s_begin:s_end]        seq_y_mark = self.data_stamp[r_begin:r_end]        return seq_x, seq_y, seq_x_mark, seq_y_mark
  • 光看注释可能对各区间划分不那么清楚,这里我画了一幅示意图,希望能帮大家理解
    请添加图片描述

SCINet模型架构(SCINet)

  • 打开model文件夹,找到SCINet类,先定位到main()函数,可以看到main()函数这里实例化了一个SCINet类,并将参数传入其中
if __name__ == '__main__':    parser = argparse.ArgumentParser()    parser.add_argument('--window_size', type=int, default=96)    parser.add_argument('--horizon', type=int, default=12)    parser.add_argument('--dropout', type=float, default=0.5)    parser.add_argument('--groups', type=int, default=1)    parser.add_argument('--hidden-size', default=1, type=int, help='hidden channel of module')    parser.add_argument('--INN', default=1, type=int, help='use INN or basic strategy')    parser.add_argument('--kernel', default=3, type=int, help='kernel size')    parser.add_argument('--dilation', default=1, type=int, help='dilation')    parser.add_argument('--positionalEcoding', type=bool, default=True)    parser.add_argument('--single_step_output_One', type=int, default=0)    args = parser.parse_args()    # 实例化SCINet类    model = SCINet(output_len = args.horizon, input_len= args.window_size, input_dim = 9, hid_size = args.hidden_size, num_stacks = 1,                num_levels = 3, concat_len = 0, groups = args.groups, kernel = args.kernel, dropout = args.dropout,                 single_step_output_One = args.single_step_output_One, positionalE =  args.positionalEcoding, modified = True).cuda()    x = torch.randn(32, 96, 9).cuda()    y = model(x)    print(y.shape)
  • 下面我们从头开始结合论文中的架构图讲解代码。

Splitting类(奇偶序列分离)

在这里插入图片描述

  • 这部分比较简单,就是通过数据下标将序列分为奇序列与偶序列
class Splitting(nn.Module):    def __init__(self):        super(Splitting, self).__init__()    def even(self, x):        # 将奇序列分离        return x[:, ::2, :]    def odd(self, x):        # 将偶序列分离        return x[:, 1::2, :]    def forward(self, x):        return (self.even(x), self.odd(x))

Interactor类(下采样与交互学习)

  • 这一部分将奇、偶序列分别使用不同分辨率的卷积捕捉时间信息,然后两序列分别进行加减运算,模型架构图
    在这里插入图片描述

  • 注释写的非常清楚,这一部分建议多琢磨

class Interactor(nn.Module):    def __init__(self, in_planes, splitting=True,                 kernel = 5, dropout=0.5, groups = 1, hidden_size = 1, INN = True):        super(Interactor, self).__init__()        self.modified = INN        self.kernel_size = kernel        self.dilation = 1        self.dropout = dropout        self.hidden_size = hidden_size        self.groups = groups        # 如果通道数为偶数        if self.kernel_size % 2 == 0:            # 1 * (kernel -2) // 2 + 1            pad_l = self.dilation * (self.kernel_size - 2) // 2 + 1 #by default: stride==1            # 1 * kernel // 2 + 1            pad_r = self.dilation * (self.kernel_size) // 2 + 1 #by default: stride==1            # 如果kernel_size = 4, pda_l = 2,pad_r = 3        # 如果通道数为奇数        else:            pad_l = self.dilation * (self.kernel_size - 1) // 2 + 1 # we fix the kernel size of the second layer as 3.            pad_r = self.dilation * (self.kernel_size - 1) // 2 + 1            # 如果kernel_size = 3, pda_l = 2,pad_r = 2        self.splitting = splitting        self.split = Splitting()        modules_P = []        modules_U = []        modules_psi = []        modules_phi = []        prev_size = 1        size_hidden = self.hidden_size        modules_P += [            # ReplicationPad1d用输入边界的反射来填充输入张量            nn.ReplicationPad1d((pad_l, pad_r)),            # 1维卷积(in_channels,out_channels,kernel_size)-->(7,7,5)            nn.Conv1d(in_planes * prev_size, int(in_planes * size_hidden),                      kernel_size=self.kernel_size, dilation=self.dilation, stride=1, groups= self.groups),            # LeakyReLU激活层            nn.LeakyReLU(negative_slope=0.01, inplace=True),            # Dropout层            nn.Dropout(self.dropout),            # 1维卷积(in_channels,out_channels,kernel_size)-->(7,7,3)            nn.Conv1d(int(in_planes * size_hidden), in_planes,                      kernel_size=3, stride=1, groups= self.groups),            # Tanh激活层            nn.Tanh()        ]        modules_U += [            # ReplicationPad1d用输入边界的反射来填充输入张量            nn.ReplicationPad1d((pad_l, pad_r)),            # 1维卷积(in_channels, out_channels,kernel_size)-->(7,7,5)            nn.Conv1d(in_planes * prev_size, int(in_planes * size_hidden),                      kernel_size=self.kernel_size, dilation=self.dilation, stride=1, groups= self.groups),            # LeakyReLu激活层            nn.LeakyReLU(negative_slope=0.01, inplace=True),            # Dropout层            nn.Dropout(self.dropout),            # 1维卷积(in_channels, out_channels,kernel_size)-->(7,7,3)            nn.Conv1d(int(in_planes * size_hidden), in_planes,                      kernel_size=3, stride=1, groups= self.groups),            # Tanh激活层            nn.Tanh()        ]        modules_phi += [            # ReplicationPad1d用输入边界的反射来填充输入张量            nn.ReplicationPad1d((pad_l, pad_r)),            # 1维卷积(in_channels, out_channels,kernel_size)-->(7,7,5)            nn.Conv1d(in_planes * prev_size, int(in_planes * size_hidden),                      kernel_size=self.kernel_size, dilation=self.dilation, stride=1, groups= self.groups),            # LeakyReLU激活层            nn.LeakyReLU(negative_slope=0.01, inplace=True),            # Dropout层            nn.Dropout(self.dropout),            # 1维卷积(in_channels, out_channels,kernel_size)-->(7,7,3)            nn.Conv1d(int(in_planes * size_hidden), in_planes,                      kernel_size=3, stride=1, groups= self.groups),            # Tanh激活层            nn.Tanh()        ]        modules_psi += [            # ReplicationPad1d用输入边界的反射来填充输入张量            nn.ReplicationPad1d((pad_l, pad_r)),            # 一维卷积(in_channels, out_channels,kernel_size)-->(7,7,5)            nn.Conv1d(in_planes * prev_size, int(in_planes * size_hidden),                      kernel_size=self.kernel_size, dilation=self.dilation, stride=1, groups= self.groups),            # LeakyReLU激活层            nn.LeakyReLU(negative_slope=0.01, inplace=True),            # Dropout层            nn.Dropout(self.dropout),            # 1维卷积(in_channels, out_channels,kernel_size)-->(7,7,3)            nn.Conv1d(int(in_planes * size_hidden), in_planes,                      kernel_size=3, stride=1, groups= self.groups),            # Tanh激活层            nn.Tanh()        ]        self.phi = nn.Sequential(*modules_phi)        self.psi = nn.Sequential(*modules_psi)        self.P = nn.Sequential(*modules_P)        self.U = nn.Sequential(*modules_U)    def forward(self, x):        # 将奇偶序列分隔        if self.splitting:            (x_even, x_odd) = self.split(x)        else:            (x_even, x_odd) = x        # 如果INN不为0        if self.modified:            # 交换奇、偶序列维度[B,L,D] --> [B,D,L]            x_even = x_even.permute(0, 2, 1)            x_odd = x_odd.permute(0, 2, 1)            # mul()函数矩阵点乘,计算经过phi层的指数值            d = x_odd.mul(torch.exp(self.phi(x_even)))            c = x_even.mul(torch.exp(self.psi(x_odd)))            # 更新奇序列(奇序列 + 经过U层的偶序列)            x_even_update = c + self.U(d)            # 更新偶序列(偶序列 - 经过P层的奇序列)            x_odd_update = d - self.P(c)            return (x_even_update, x_odd_update)        else:            # 不计算指数值            x_even = x_even.permute(0, 2, 1)            x_odd = x_odd.permute(0, 2, 1)            d = x_odd - self.P(x_even)            c = x_even + self.U(d)            return (c, d)

InteractorLevel类

  • 该类主要实例化Interactor类,并得到奇、偶序列特征
class InteractorLevel(nn.Module):    def __init__(self, in_planes, kernel, dropout, groups , hidden_size, INN):        super(InteractorLevel, self).__init__()        self.level = Interactor(in_planes = in_planes, splitting=True,                 kernel = kernel, dropout=dropout, groups = groups, hidden_size = hidden_size, INN = INN)    def forward(self, x):        (x_even_update, x_odd_update) = self.level(x)        return (x_even_update, x_odd_update)

LevelSCINet类

  • 该类主要实例化InteractorLevel类,并将得到的奇、偶序列特征进行维度交换方便SCINet_Tree框架运算
class LevelSCINet(nn.Module):    def __init__(self,in_planes, kernel_size, dropout, groups, hidden_size, INN):        super(LevelSCINet, self).__init__()        self.interact = InteractorLevel(in_planes= in_planes, kernel = kernel_size, dropout = dropout, groups =groups , hidden_size = hidden_size, INN = INN)    def forward(self, x):        (x_even_update, x_odd_update) = self.interact(x)        # 交换奇、偶序列维度[B,D,L] --> [B,T,D]        return x_even_update.permute(0, 2, 1), x_odd_update.permute(0, 2, 1)

SCINet_Tree类

  • 这就是论文中提到的二叉树结构,可以更有效的捕捉时间序列的长短期依赖,网络框架图:
    在这里插入图片描述

  • 这部分框架为SCINet的核心框架,建议认真阅读

class SCINet_Tree(nn.Module):    def __init__(self, in_planes, current_level, kernel_size, dropout, groups, hidden_size, INN):        super().__init__()        self.current_level = current_level        self.workingblock = LevelSCINet(            in_planes = in_planes,            kernel_size = kernel_size,            dropout = dropout,            groups= groups,            hidden_size = hidden_size,            INN = INN)        # 如果current_level不为0        if current_level!=0:            self.SCINet_Tree_odd=SCINet_Tree(in_planes, current_level-1, kernel_size, dropout, groups, hidden_size, INN)            self.SCINet_Tree_even=SCINet_Tree(in_planes, current_level-1, kernel_size, dropout, groups, hidden_size, INN)        def zip_up_the_pants(self, even, odd):        # 交换奇数据下标(B,L,D) --> (L,B,D)        even = even.permute(1, 0, 2)        odd = odd.permute(1, 0, 2) #L, B, D        # 取序列长度        even_len = even.shape[0]        odd_len = odd.shape[0]        # 取奇、偶数据序列长度小值        mlen = min((odd_len, even_len))        _ = []        for i in range(mlen):            # 在第1维度前增加1个维度            # _.shape:[12],even.shape:[12,32,7],odd.shape:[12,32,7]            _.append(even[i].unsqueeze(0))            _.append(odd[i].unsqueeze(0))        # 如果偶序列长度 < 奇序列长度        if odd_len < even_len:             _.append(even[-1].unsqueeze(0))        # 将张量按照第1维度拼接        return torch.cat(_,0).permute(1,0,2) #B, L, D            def forward(self, x):        # 取得更新后的奇、偶序列        x_even_update, x_odd_update= self.workingblock(x)        # We recursively reordered these sub-series. You can run the ./utils/recursive_demo.py to emulate this procedure.         if self.current_level == 0:            return self.zip_up_the_pants(x_even_update, x_odd_update)        else:            return self.zip_up_the_pants(self.SCINet_Tree_even(x_even_update), self.SCINet_Tree_odd(x_odd_update))

EncoderTree类(编码器)

  • 实例化SCINet_Tree类,编码器,让输入进入SCINet_Tree模块
class EncoderTree(nn.Module):    def __init__(self, in_planes,  num_levels, kernel_size, dropout, groups, hidden_size, INN):        super().__init__()        self.levels=num_levels        self.SCINet_Tree = SCINet_Tree(            in_planes = in_planes,            current_level = num_levels-1,            kernel_size = kernel_size,            dropout =dropout ,            groups = groups,            hidden_size = hidden_size,            INN = INN)            def forward(self, x):        # 编码器,让输入进入SCINet_Tree模块        x= self.SCINet_Tree(x)        return x

SCINet类(堆叠模型整体架构)

  • 在该类中实现了整个模型的搭建,当然也包含架构图的最后一张,stacked堆叠、解码器、RIN激活等等
    在这里插入图片描述
class SCINet(nn.Module):    def __init__(self, output_len, input_len, input_dim = 9, hid_size = 1, num_stacks = 1,                num_levels = 3, num_decoder_layer = 1, concat_len = 0, groups = 1, kernel = 5, dropout = 0.5,                 single_step_output_One = 0, input_len_seg = 0, positionalE = False, modified = True, RIN=False):        super(SCINet, self).__init__()        self.input_dim = input_dim        self.input_len = input_len        self.output_len = output_len        self.hidden_size = hid_size        self.num_levels = num_levels        self.groups = groups        self.modified = modified        self.kernel_size = kernel        self.dropout = dropout        self.single_step_output_One = single_step_output_One        self.concat_len = concat_len        self.pe = positionalE        self.RIN=RIN        self.num_decoder_layer = num_decoder_layer        self.blocks1 = EncoderTree(            in_planes=self.input_dim,            num_levels = self.num_levels,            kernel_size = self.kernel_size,            dropout = self.dropout,            groups = self.groups,            hidden_size = self.hidden_size,            INN =  modified)        if num_stacks == 2: # we only implement two stacks at most.            self.blocks2 = EncoderTree(                in_planes=self.input_dim,            num_levels = self.num_levels,            kernel_size = self.kernel_size,            dropout = self.dropout,            groups = self.groups,            hidden_size = self.hidden_size,            INN =  modified)        self.stacks = num_stacks        for m in self.modules():            # 如果m为2维卷积层            if isinstance(m, nn.Conv2d):                # 初始化权重                n = m.kernel_size[0] * m.kernel_size[1] * m.out_channels                m.weight.data.normal_(0, math.sqrt(2. / n))            elif isinstance(m, nn.BatchNorm2d):                m.weight.data.fill_(1)                m.bias.data.zero_()            elif isinstance(m, nn.Linear):                m.bias.data.zero_()        self.projection1 = nn.Conv1d(self.input_len, self.output_len, kernel_size=1, stride=1, bias=False)        self.div_projection = nn.ModuleList()        self.overlap_len = self.input_len//4        self.div_len = self.input_len//6        # 若解码层大于1        if self.num_decoder_layer > 1:            # pro1层变为线性层            self.projection1 = nn.Linear(self.input_len, self.output_len)            # 循环range(解码层-1)            for layer_idx in range(self.num_decoder_layer-1):                # 创建子模块列表                div_projection = nn.ModuleList()                for i in range(6):                    # 计算全连接层输出维度                    # 若input_len = 96 --> div_len = 16,overlap_len = 24                    # len = 24 --> 24 --> 24 --> 24 --> 24 --> 16                    lens = min(i*self.div_len+self.overlap_len,self.input_len) - i*self.div_len                    # (24,16) --> (24,16) --> (24,16) --> (24,16) --> (24,16) --> (16,16)                    div_projection.append(nn.Linear(lens, self.div_len))                self.div_projection.append(div_projection)        if self.single_step_output_One: # only output the N_th timestep.            if self.stacks == 2:                if self.concat_len:                    self.projection2 = nn.Conv1d(self.concat_len + self.output_len, 1,                    kernel_size = 1, bias = False)                else:                    self.projection2 = nn.Conv1d(self.input_len + self.output_len, 1,                    kernel_size = 1, bias = False)        else: # output the N timesteps.            if self.stacks == 2:                if self.concat_len:                    self.projection2 = nn.Conv1d(self.concat_len + self.output_len, self.output_len,                    kernel_size = 1, bias = False)                else:                    self.projection2 = nn.Conv1d(self.input_len + self.output_len, self.output_len,                    kernel_size = 1, bias = False)        # For positional encoding        self.pe_hidden_size = input_dim        if self.pe_hidden_size % 2 == 1:            self.pe_hidden_size += 1            num_timescales = self.pe_hidden_size // 2        max_timescale = 10000.0        min_timescale = 1.0        log_timescale_increment = (                math.log(float(max_timescale) / float(min_timescale)) /                max(num_timescales - 1, 1))        temp = torch.arange(num_timescales, dtype=torch.float32)        inv_timescales = min_timescale * torch.exp(            torch.arange(num_timescales, dtype=torch.float32) *            -log_timescale_increment)        self.reGISter_buffer('inv_timescales', inv_timescales)        ### RIN Parameters ###        if self.RIN:            self.affine_weight = nn.Parameter(torch.ones(1, 1, input_dim))            self.affine_bias = nn.Parameter(torch.zeros(1, 1, input_dim))        def get_position_encoding(self, x):        # 取数据第2个维度        max_length = x.size()[1]        # 位置编码        position = torch.arange(max_length, dtype=torch.float32, device=x.device)        # 在第2个维度前面再添加一个维度        temp1 = position.unsqueeze(1)  # 5 1        temp2 = self.inv_timescales.unsqueeze(0)  # 1 256        # 矩阵乘法        scaled_time = position.unsqueeze(1) * self.inv_timescales.unsqueeze(0)  # 5 256        # 拼接sin(特征)和cos(特征)        signal = torch.cat([torch.sin(scaled_time), torch.cos(scaled_time)], dim=1)  #[T, C]        # pad操作        signal = F.pad(signal, (0, 0, 0, self.pe_hidden_size % 2))        # 改变数组维度,并使其称为视图        signal = signal.view(1, max_length, self.pe_hidden_size)            return signal    def forward(self, x):        # 判断输出序列长度合理性        assert self.input_len % (np.power(2, self.num_levels)) == 0        # 如果需要位置编码        if self.pe:            pe = self.get_position_encoding(x)            if pe.shape[2] > x.shape[2]:                x += pe[:, :, :-1]            else:                x += self.get_position_encoding(x)        # 若使用RIN激活        if self.RIN:            print('/// RIN ACTIVATED ///\r',end='')            means = x.mean(1, keepdim=True).detach()            #mean            x = x - means            #var            stdev = torch.sqrt(torch.var(x, dim=1, keepdim=True, unbiased=False) + 1e-5)            x /= stdev            # affine            # print(x.shape,self.affine_weight.shape,self.affine_bias.shape)            x = x * self.affine_weight + self.affine_bias        # 第一层stack        res1 = x        # 进入编码器        x = self.blocks1(x)        # 相加操作        x += res1        # 如果解码层为1        if self.num_decoder_layer == 1:            # 经过1维卷积层Conv1d(input_len, output_len, kernel_size = 1),得到结果            x = self.projection1(x)        else:            # 交换维度(B,L,D) --> (B,D,L)            x = x.permute(0,2,1)            for div_projection in self.div_projection:                # 创建与x相同的全0矩阵                output = torch.zeros(x.shape,dtype=x.dtype).cuda()                # 取出下标和对应层                for i, div_layer in enumerate(div_projection):                    # 赋值对应维度                    div_x = x[:,:,i*self.div_len:min(i*self.div_len+self.overlap_len,self.input_len)]                    output[:,:,i*self.div_len:(i+1)*self.div_len] = div_layer(div_x)                x = output            # 经过1维卷积层Conv1d(input_len, output_len, kernel_size = 1),得到结果            x = self.projection1(x)            # 交换维度(B,L,D) --> (B,D,L)            x = x.permute(0,2,1)        # 如果stacks为1        if self.stacks == 1:            # 反转RIN激活            if self.RIN:                # x - 偏置                x = x - self.affine_bias                # x / 权值                x = x / (self.affine_weight + 1e-10)                # x * 标准差                x = x * stdev                # x + 平均值                x = x + means            return x        # 若stacks为2        elif self.stacks == 2:            # 赋值中间层输出            MidOutPut = x            # 若concat_len不为0            if self.concat_len:                # 将res1(部分)和x在沿1维度进行拼接                x = torch.cat((res1[:, -self.concat_len:,:], x), dim=1)            else:                # 将res1(部分)和x在沿1维度进行拼接                x = torch.cat((res1, x), dim=1)            # 第2层stacks            res2 = x            # 进入编码层            x = self.blocks2(x)            # 加法操作            x += res2            # 进入1维卷积Conv1d(output_len, output_len, kernel_size = 1)            x = self.projection2(x)                        # 反转RIN激活            if self.RIN:                MidOutPut = MidOutPut - self.affine_bias                MidOutPut = MidOutPut / (self.affine_weight + 1e-10)                MidOutPut = MidOutPut * stdev                MidOutPut = MidOutPut + means            # 反转RIN激活            if self.RIN:                x = x - self.affine_bias                x = x / (self.affine_weight + 1e-10)                x = x * stdev                x = x + means            # 输出结果以及中间层特征输出            return x, MidOutPutdef get_variable(x):    x = Variable(x)    return x.cuda() if torch.cuda.is_available() else x
  • 有一点奇怪的是,在论文中stack可以达到3,但是在该代码中只要stack大于2就会报错,但其实当你读完模型架构以后,你完全可以将这个约束解除,因为我们不需要做实验,所以3层中间的2层不需要输出特征,只要最后一层结果就行。

模型训练(exp_ETTh)

  • 这里我主要注释一下train函数,validtest函数都差不多,只是有些操作不需要删减了而已。
    def train(self, setting):        # 取得训练、验证、测试数据及数据加载器        train_data, train_loader = self._get_data(flag = 'train')        valid_data, valid_loader = self._get_data(flag = 'val')        test_data, test_loader = self._get_data(flag = 'test')        path = os.path.join(self.args.checkpoints, setting)        # 创建模型保存路径        if not os.path.exists(path):            os.makedirs(path)        # 绘制模型训练信息曲线        writer = SummaryWriter('event/run_ETTh/{}'.format(self.args.model_name))        # 获取当前时间        time_now = time.time()        # 取训练步数        train_steps = len(train_loader)        # 设置早停参数        early_stopping = EarlyStopping(patience=self.args.patience, verbose=True)        # 选择优化        model_optim = self._select_optimizer()        # 选择损失函数        criterion =  self._select_criterion(self.args.loss)        # 如果多GPU并行        if self.args.use_amp:            scaler = torch.cuda.amp.GradScaler()        # 如果断点续传训练        if self.args.resume:            self.model, lr, epoch_start = load_model(self.model, path, model_name=self.args.data, horizon=self.args.horizon)        else:            epoch_start = 0        for epoch in range(epoch_start, self.args.train_epochs):            iter_count = 0            train_loss = []                        self.model.train()            epoch_time = time.time()            for i, (batch_x,batch_y,batch_x_mark,batch_y_mark) in enumerate(train_loader):                iter_count += 1    model_optim.zero_grad()                # 得到预测值、反归一化预测值、中间层输出、反归一化中间层输出、真实值、反归一化真实值                pred, pred_scale, mid, mid_scale, true, true_scale = self._process_one_batch_SCINet(                    train_data, batch_x, batch_y)                # stacks为1                if self.args.stacks == 1:                    # loss损失为mae(真实值+预测值)                    loss = criterion(pred, true)                # stacks为2                elif self.args.stacks == 2:                    # loss损失为mae(真实值,预测值) + mae(中间层输出,预测值)                    loss = criterion(pred, true) + criterion(mid, true)                else:                    print('Error!')                # 将loss信息记录到train_loss列表中                train_loss.append(loss.item())                # 100个训练步数输出一次训练、验证、测试损失信息                if (i+1) % 100==0:                    print("\titers: {0}, epoch: {1} | loss: {2:.7f}".format(i + 1, epoch + 1, loss.item()))                    speed = (time.time()-time_now)/iter_count                    left_time = speed*((self.args.train_epochs - epoch)*train_steps - i)                    print('\tspeed: {:.4f}s/iter; left time: {:.4f}s'.format(speed, left_time))                    iter_count = 0                    time_now = time.time()                # 如果有分布式计算                if self.args.use_amp:                    print('use amp')                        scaler.scale(loss).backward()                    scaler.step(model_optim)                    scaler.update()                else:                    # 反向传播                    loss.backward()                    # 更新优化器                    model_optim.step()            # 打印关键信息            print("Epoch: {} cost time: {}".format(epoch+1, time.time()-epoch_time))            train_loss = np.average(train_loss)            print('--------start to validate-----------')            valid_loss = self.valid(valid_data, valid_loader, criterion)            print('--------start to test-----------')            test_loss = self.valid(test_data, test_loader, criterion)            print("Epoch: {0}, Steps: {1} | Train Loss: {2:.7f} valid Loss: {3:.7f} Test Loss: {4:.7f}".format(                epoch + 1, train_steps, train_loss, valid_loss, test_loss))            # 记录训练、测试、验证集损失下降情况            writer.add_Scalar('train_loss', train_loss, global_step=epoch)            writer.add_scalar('valid_loss', valid_loss, global_step=epoch)            writer.add_scalar('test_loss', test_loss, global_step=epoch)            # 测算早停策略            early_stopping(valid_loss, self.model, path)            # 若达到早停标准            if early_stopping.early_stop:                print("Early stopping")                break            # 更新学习率            lr = adjust_learning_rate(model_optim, epoch+1, self.args)        # 保存模型        save_model(epoch, lr, self.model, path, model_name=self.args.data, horizon=self.args.pred_len)        # 保存表现最好模型        best_model_path = path+'/'+'checkpoint.pth'        # 加载表现最好模型        self.model.load_state_dict(torch.load(best_model_path))        # 返回模型        return self.model

结果展示

  • 我用kaggle上的GPU(P100)跑的,时间很短,跑这个ETTh这个数据集需要40分钟左右
>>>>>>>start training : SCINet_ETTh1_ftM_sl96_ll48_pl48_lr0.0001_bs32_hid1_s1_l3_dp0.5_invFalse_itr0>>>>>>>>>>>>>>>>>>>>>>>>>>train 8497val 2833test 2833iters: 100, epoch: 41 | loss: 0.3506456speed: 0.2028s/iter; left time: 3204.9921siters: 200, epoch: 41 | loss: 0.3641948speed: 0.0906s/iter; left time: 1422.0832sEpoch: 41 cost time: 24.570287466049194--------start to validate-----------normed mse:0.5108, mae:0.4747, rmse:0.7147, mape:5.9908, mspe:25702.7811, corr:0.7920denormed mse:7.2514, mae:1.5723, rmse:2.6928, mape:inf, mspe:inf, corr:0.7920--------start to test-----------normed mse:0.3664, mae:0.4001, rmse:0.6053, mape:7.6782, mspe:30989.9618, corr:0.7178denormed mse:8.2571, mae:1.5634, rmse:2.8735, mape:inf, mspe:inf, corr:0.7178Epoch: 41, Steps: 265 | Train Loss: 0.3702444 valid Loss: 0.4746509 Test Loss: 0.4000920iters: 100, epoch: 42 | loss: 0.3643743speed: 0.2015s/iter; left time: 3130.5999siters: 200, epoch: 42 | loss: 0.3464577speed: 0.1015s/iter; left time: 1566.1000sEpoch: 42 cost time: 25.76799440383911--------start to validate-----------normed mse:0.5101, mae:0.4743, rmse:0.7142, mape:5.9707, mspe:25459.9669, corr:0.7923denormed mse:7.2425, mae:1.5713, rmse:2.6912, mape:inf, mspe:inf, corr:0.7923--------start to test-----------normed mse:0.3670, mae:0.4010, rmse:0.6058, mape:7.6564, mspe:30790.0708, corr:0.7179denormed mse:8.2969, mae:1.5701, rmse:2.8804, mape:inf, mspe:inf, corr:0.7179Epoch: 42, Steps: 265 | Train Loss: 0.3700826 valid Loss: 0.4743312 Test Loss: 0.4009686iters: 100, epoch: 43 | loss: 0.3849421speed: 0.2019s/iter; left time: 3083.0659siters: 200, epoch: 43 | loss: 0.3757646speed: 0.0981s/iter; left time: 1487.8231sEpoch: 43 cost time: 25.635279893875122--------start to validate-----------normed mse:0.5105, mae:0.4744, rmse:0.7145, mape:5.9568, mspe:25381.2960, corr:0.7922denormed mse:7.2566, mae:1.5721, rmse:2.6938, mape:inf, mspe:inf, corr:0.7922--------start to test-----------normed mse:0.3674, mae:0.4014, rmse:0.6061, mape:7.6480, mspe:30700.9283, corr:0.7180denormed mse:8.3153, mae:1.5732, rmse:2.8836, mape:inf, mspe:inf, corr:0.7180Epoch: 43, Steps: 265 | Train Loss: 0.3698175 valid Loss: 0.4744163 Test Loss: 0.4013726Early stopping>>>>>>>testing : SCINet_ETTh1_ftM_sl96_ll48_pl48_lr0.0001_bs32_hid1_s1_l3_dp0.5_invFalse_itr0<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<test 2833normed mse:0.3660, mae:0.3998, rmse:0.6050, mape:7.7062, mspe:31254.7139, corr:0.7174TTTT denormed mse:8.2374, mae:1.5608, rmse:2.8701, mape:inf, mspe:inf, corr:0.7174Final mean normed mse:0.3660,mae:0.3998,denormed mse:8.2374,mae:1.5608
  • 跑完以后项目文件中会生成两个文件夹,exp文件夹中存放模型文件,后缀名为.pht;event文件夹中有tensorboard记录的loss文件,这里展示一下
    请添加图片描述

后记

  • 如果大家有自定义项目(跑自己数据)的需求,可以在文章下留言,后期有时间我会专门写一篇SCINet模型如何自定义项目,以及哪些参数需要着重调整,该怎么调等等。

来源地址:https://blog.csdn.net/qq_20144897/article/details/128619564

--结束END--

本文标题: 时间序列模型SCINet(代码解析)

本文链接: https://www.lsjlt.com/news/402216.html(转载时请注明来源链接)

有问题或投稿请发送至: 邮箱/279061341@qq.com    QQ/279061341

猜你喜欢
软考高级职称资格查询
编程网,编程工程师的家园,是目前国内优秀的开源技术社区之一,形成了由开源软件库、代码分享、资讯、协作翻译、讨论区和博客等几大频道内容,为IT开发者提供了一个发现、使用、并交流开源技术的平台。
  • 官方手机版

  • 微信公众号

  • 商务合作