获取 CSV 文件并按天将其保存到单独的 MATLAB 文件中

Posted 2023-05-07

【中文标题】获取 CSV 文件并按天将其保存到单独的 MATLAB 文件中

【英文标题】：Take CSV file and save it into separate MATLAB files by day

【发布时间】：2016-04-11 04:54:33

【问题描述】：

我是 Matlab 新手，我需要在文件中为每一天创建 .mat 文件。 link to CSV Files

代码如下，我遇到的问题在注释掉的部分。我基本上需要为每一天保存一个单独的 .mat 文件，该文件存储在第 1 列中。谢谢大家。

clear;
Info=csvread('tester.csv');
%header=csvread('header.csv');
days=unique(Info(:,1));
numdays= length(days);
for i = 1:numdays

    %Info.header=header;

    %write headers in 
    %Info.data=Info(Info(:,1)==days(i),:);

    str = sprintf('save data%i.mat', i);
    eval(str);
end

【问题讨论】：

你们有在线的 tester.csv 和 header.csv 吗？

【参考方案1】：

你可以这样做：

fid = fopen('tester_small.csv','r'); % // open the file
h = fgetl(fid); % // read the first line which is  the header
headers = strsplit(h,','); % // split the headers into a cell array
formatSpec = '%f%f%f%f%f%f'; % // set the format for the data
data = textscan(fid, formatSpec, 'Delimiter', ','); %//     read in the data
fclose(fid); % // close the file

Info=cell2mat(data); 
days=unique(Info(:,1));
numdays= length(days);
for cnt = 1:numdays
    % // clear the variable between each run so 
    % // that you don't include data from previous iteration
   clear S;
   S.header = headers;
   S.data=Info(Info(:,1)==days(cnt),:);
   filename = sprintf('data%i.mat', cnt);
   save(filename,'S');
end

---

这是tester_small.csv，即文件的前十行：

Date,Minutes,DC114T,DCRCS103,DCRCS104,DCRCS110
40484,5,72.681519,692.999939,689.999878,559.999878
40484,10,72.681519,695.19989,693.799866,558.799927
40484,15,72.681519,693.999939,693.799866,560.999878
40484,20,72.681519,692.19989,694.999878,558.799927
40484,25,72.681519,693.19989,696.999939,558.999939
40484,30,72.681519,692.19989,699.999878,560.799927
40484,35,72.681519,690.999878,700.999878,563.999939
40484,40,72.681519,696.199951,697.999878,562.999939
40484,45,72.681519,696.199951,696.999939,564.999878

这是加载文件时的结果。

load data1.mat
>> S
S =

  scalar structure containing the fields:

header =

  [1,1] = Date
  [1,2] = Minutes
  [1,3] = DC114T
  [1,4] = DCRCS103
  [1,5] = DCRCS104
  [1,6] = DCRCS110

data =

  4.0484e+004  5.0000e+000  7.2682e+001  6.9300e+002  6.9000e+002  5.6000e+002
  4.0484e+004  1.0000e+001  7.2682e+001  6.9520e+002  6.9380e+002  5.5880e+002
  4.0484e+004  1.5000e+001  7.2682e+001  6.9400e+002  6.9380e+002  5.6100e+002
  4.0484e+004  2.0000e+001  7.2682e+001  6.9220e+002  6.9500e+002  5.5880e+002
  4.0484e+004  2.5000e+001  7.2682e+001  6.9320e+002  6.9700e+002  5.5900e+002
  4.0484e+004  3.0000e+001  7.2682e+001  6.9220e+002  7.0000e+002  5.6080e+002
  4.0484e+004  3.5000e+001  7.2682e+001  6.9100e+002  7.0100e+002  5.6400e+002
  4.0484e+004  4.0000e+001  7.2682e+001  6.9620e+002  6.9800e+002  5.6300e+002
  4.0484e+004  4.5000e+001  7.2682e+001  6.9620e+002  6.9700e+002  5.6500e+002

【讨论】：

那么你的文件一定有问题，因为它显然对我有用。 csvread 没有任何问题。只是它只接受数值。您的标题不是数字。如果您删除标题，您也许可以使用csvread，但我会质疑为什么您有一个带有标题的文件和一个带有数据的文件，当您可以组合它们时。最终，你应该做最适合你的事情。

【参考方案2】：

假设我们有.csv 文件

header.csv
 Date,Time,Data1,Data2,...,DataN

tester.csv
 Date,Time,Data1,Data2,...,DataN
 DtNO,TiNO, D11, D12, ... ,D1N
 ...

然后运行此代码，我们将整个.csv 加载到一个数组中，按Date 列将其分组，然后将其导出到testdata-<Date>.mat 文件中。

Header=importdata('header.csv',',');
Testdata=importdata('tester.csv',',',1);
Date=Testdata(1,1);
EndDate=Testdata(end,1);
Advance=true;

while Advance
  %% Find the part for one Date
  Indices=find(Testdata(:,1)==Date);
  %% Pick whole data set for perticullar Date
  Data=Testdata(Indices,:);
  %% Save Data, Header and Date variables only
  save(['testdata-' Date '.mat','Data','Date','Header');
  %% Advance to next Date
    if Date~=EndDate
      Date=TestData(Indices(end),1);
    else
      Advance=false;
    end
end