Question

I write this code for calculating datenum values:

     Test_table = table2dataset(Test_table);

       t1 = Test_table (:,3);
       c1 =dataset2cell(t1); 
       C1 = strrep(c1(2:end), '"', '');
       formatIn = 'yyyy-mm-dd HH:MM:SS.FFF';
        T1= datenum(C1(1:end),formatIn);

I have data in table format, which are converted into datasets, then from there I extracted timestamp in the form of a cell array. But when I run the code I am getting the following error:

The input to DATENUM was not an array of character vectors.

The entire timestamps (t1) in cell array format are uploaded into this site here: But still getting an error , 'Error using strrep Cell elements must be character vectors.' . What is wrong here ?

Solution :

After the struggling of 1 day, I am able to solve this problem. Actually the error I am getting because I have data sets in following format [1x1 string] which is wrong hence I am geeting error for my code. So to solve this problem I used cellstr function which converted my entire datasets into cell. And hence now working. So correct code should be like this ,

    t1 = table2dataset(:,3);
    C1 = cellstr(t1);
     d1 = strrep(C1, '"', '');

         formatIn = 'yyyy-mm-dd HH:MM:SS.FFF';
         t1 = datenum(d1, formatIn);

Hope this help for future visitor !

Answer 1

好的，你有以下单元格数组：

t1 = {'"2009-04-13 04:20:00.000"'
      '"2009-04-13 04:30:00.000"'
      '"2009-04-13 04:40:00.000"'
      '"2009-04-13 04:50:00.000"'
      '"2009-04-13 05:00:00.000"'
      '"2009-04-13 05:10:00.000"'
      '"2009-04-13 09:40:00.000"'
      '"2009-04-13 09:50:00.000"'
      '"2009-04-13 10:00:00.000"'
      '"2009-04-13 10:10:00.000"'}

每个日期都是一个字符串，因为它被单个引号'包围，并且由于您的数据提取，每个日期包含双引号。要从整个单元格数组中删除双引号，请将其替换为空字符串''（这是两个单引号，两者之间没有空格）。使用strrep执行此操作。

c1 = strrep(t1, '"', '');

% c1 = {'2009-04-13 04:20:00.000'
%       '2009-04-13 04:30:00.000'
%       '2009-04-13 04:40:00.000'
%       '2009-04-13 04:50:00.000'
%       '2009-04-13 05:00:00.000'
%       '2009-04-13 05:10:00.000'
%       '2009-04-13 09:40:00.000'
%       '2009-04-13 09:50:00.000'
%       '2009-04-13 10:00:00.000'
%       '2009-04-13 10:10:00.000'}

然后您可以将其传递给datevec或datenum。

formatIn = 'yyyy-mm-dd HH:MM:SS.FFF';
T1 = datevec(c1, formatIn);

%    year          month       day          hour       minutes     seconds
%T1=[2009           4          13           4          20           0
%    2009           4          13           4          30           0
%    2009           4          13           4          40           0
%    2009           4          13           4          50           0
%    2009           4          13           5           0           0
%    2009           4          13           5          10           0
%    2009           4          13           9          40           0
%    2009           4          13           9          50           0
%    2009           4          13          10           0           0
%    2009           4          13          10          10           0]

using datenum for timestamp using Matlab

1 个答案: