使用NAN填充缺少的时间戳数据行-MATLAB [英] Populate missing timestamp data rows with NAN - MATLAB

问题描述

我有一个缺少某些时间戳的数据集.到目前为止，我已经编写了代码，

I have one dataset in which some timestamps are missing. I have written code so far as below,

x = table2dataset(Testing_data);
T1 = x(:,1);              
C1 =dataset2cell(T1);
formatIn = 'yyyy-mm-dd HH:MM:SS';
t1= datenum(C1,formatIn);

% Creating 10 minutes of time interval;
avg = 10/60/24;        
tnew = [t1(1):avg:t1(end)]';
indx = round((t1-t1(1))/avg) + 1;
ynew = NaN(length(tnew),1);
ynew(indx)=t1;

% replacing missing time with NaN
t = datetime(ynew,'ConvertFrom','datenum');                 
formatIn = 'yyyy-mm-dd HH:MM:SS';
DateVector = datevec(ynew,formatIn);
dt = datestr(ynew,'yyyy-mm-dd HH:MM:SS');
ds = string(dt);

测试数据具有此处显示的三个参数，

The testing data has three parameters shown here,

     Time                       x          y
2009-04-10 02:00:00.000         1         0.1
2009-04-10 02:10:00.000         2         0.2
2009-04-10 02:30:00.000         3         0.3
2009-04-10 02:50:00.000         4         0.4

现在您可以看到，每隔10分钟，缺少时间戳(2:20和2:40)，因此我想添加该时间戳.然后，我希望x和y值是NAN.所以我的输出将是这样，

Now as you can see, for intervals of 10 minutes, there are missing timestamps (2:20 and 2:40) so I want to added that time stamp. Then I want the x and y values to be NAN. So My output would be like,

       Time                     x          y
2009-04-10 02:00:00.000         1         0.1
2009-04-10 02:10:00.000         2         0.2
2009-04-10 02:20:00.000         NaN       NaN
2009-04-10 02:30:00.000         3         0.3    
2009-04-10 02:40:00.000         NaN       NaN
2009-04-10 02:50:00.000         4         0.4

从我的代码中可以看到，我只能够添加带有时间戳的NaN，但是现在我想获取其对应的x和y值.

As you can see from my code, I am just able to add NaN with time stamp but now would like to take its corresponding x and y value which I desired.

请注意，我在上述格式中有3000多个数据行，我想对所有值执行相同的操作.

Please note I have more than 3000 data rows in the above format, I want to perform the same for my all values.

推荐答案

这似乎与您的问题矛盾；您说可以插入NaN代替丢失的时间字符串，但是在预期输出的示例中，您编写了时间字符串.

it seems to be a contradiction in your question; you say tthat you are able to insert NaN in place of the missing time string but, in the example of the expected output you wrote the time string.

您还可以参考缺少的时间戳记(2:20)，但是，如果时间步长为10分钟，则在示例数据中，还有另一个缺少的时间戳记(2:40)

Also you refer to missing time stamp (2:20) but, if the time step is 10 minutes, in your example data there is another missing time stamp (2:40)

假设:

• 您实际上想插入缺少的时间st
• 您要管理所有缺少的时间戳记

您可以如下修改代码:

• 不需要ynew时间
• 应使用tnew时间代替ynew
• 要在x和y列中插入NaN值，您必须:
  • 从dataset
  中提取它们
  • 创建两个新数组，将它们初始化为NaN
  • 将原始x和y数据插入由indx标识的位置中
  • the ynew time is not needed
  • the tnew time should be used in place of ynew
  • to insert the NaN values in the x and y column you have to:
    • extract them from the dataset
    • create two new array initializing them to NaN
    • insert the original x and y data in the location identified by indx

    在下面的内容中，您可以找到代码的更新版本.

    In the following yu can find an updated version of your code.

    • x和y数据存储在x_data和y_data数组中
    • 新的x和y数据存储在x_data_new和y_data_new数组中
    • the x and y data are stored in the x_data and y_data array
    • the new x and y data are stored in the x_data_new and y_data_new array

    在脚本的末尾，将生成两个表:第一个表是使用时间作为string生成的，第二个表是作为单元格数组的.

    at the end of the script, two table are generate: the first one is generated using the time as string, the second one as cellarray.

    代码中的注释应标识出所做的修改.

    The comments in the code should identify the modifications.

    x = table2dataset(Testing_data);
    T1 = x(:,1);
    % Get X data from the table
    x_data=x(:,2)
    % Get Y data from the table
    y_data=x(:,3)
    
    C1 =dataset2cell(T1);
    
    formatIn = 'yyyy-mm-dd HH:MM:SS';
    t1= datenum(C1(2:end),formatIn)
    
    avg = 10/60/24;        % Creating 10 minutes of time interval;
    tnew = [t1(1):avg:t1(end)]'
    indx = round((t1-t1(1))/avg) + 1
    %
    % Not Needed
    %
    % ynew = NaN(length(tnew),1);
    % ynew(indx)=t1;
    %
    % Create the new X and Y data
    %
    y_data_new = NaN(length(tnew),1)
    y_data_new(indx)=t1
    
    x_data_new=nan(length(tnew),1)
    x_data_new(indx)=x_data
    y_data_new=nan(length(tnew),1)
    y_data_new(indx)=y_data
    
    % t = datetime(ynew,'ConvertFrom','datenum')  % replacing missing time with NAN
    %
    % Use tnew instead of ynew
    %
    t = datetime(tnew,'ConvertFrom','datenum')  % replacing missing time with NAN
    formatIn = 'yyyy-mm-dd HH:MM:SS'
    % DateVector = datevec(y_data_new,formatIn)
    % dt = datestr(ynew,'yyyy-mm-dd HH:MM:SS')
    %
    % Use tnew instead of ynew
    %
    dt = datestr(tnew,'yyyy-mm-dd HH:MM:SS')
    % ds = char(dt)
    
    new_table=table(dt,x_data_new,y_data_new)
    new_table_1=table(cellstr(dt),x_data_new,y_data_new)
    

    输出为

    new_table = 
    
            dt         x_data_new    y_data_new
        ___________    __________    __________
    
        [1x19 char]      1           0.1       
        [1x19 char]      2           0.2       
        [1x19 char]    NaN           NaN       
        [1x19 char]      3           0.3       
        [1x19 char]    NaN           NaN       
        [1x19 char]      4           0.4       
    
    
    new_table_1 = 
    
                Var1             x_data_new    y_data_new
        _____________________    __________    __________
    
        '2009-04-10 02:00:00'      1           0.1       
        '2009-04-10 02:10:00'      2           0.2       
        '2009-04-10 02:20:00'    NaN           NaN       
        '2009-04-10 02:30:00'      3           0.3       
        '2009-04-10 02:40:00'    NaN           NaN       
        '2009-04-10 02:50:00'      4           0.4   
    

    希望这会有所帮助.

    Qapla'

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