Converting String Column Data to Number
显示 更早的评论
Hi everyone, i wanna ask. So i have a data readed by using this code :
filename = 'D:\KULIAH PASCASARJANA ITB\Bimbingan Tesis\abk198911dmin.txt';
startRow = 14;
formatSpec = '%10{yyyy-MM-dd}D%13s%4f%13f%10f%10f%f%[^\n\r]';
fileID = fopen(filename,'r');
textscan(fileID, '%[^\n\r]', startRow-1, 'WhiteSpace', '', 'ReturnOnError', false, 'EndOfLine', '\r\n');
dataArray = textscan(fileID, formatSpec, 'Delimiter', '', 'WhiteSpace', '', 'TextType', 'string', 'EmptyValue', NaN, 'ReturnOnError', false);
dataArray{2} = strtrim(dataArray{2});
fclose(fileID);
DATE = dataArray{:,1};
TIME = dataArray{:,2};
DOY = dataArray{:,3};
ABKX = dataArray{:,4};
ABKY = dataArray{:,5};
ABKZ = dataArray{:,6};
ABKF = dataArray{:,7};
d = str2double (TIME);
c = str2double(strrep(TIME,':',''));
for i = 1:length(c)
Converted1 = sprintf('%c%c:%c%c:%s', c(i));
Converted2 = [c(1:2), ':', c(3:4), ':', c(5:10)];
end
I cant stop thinking how to make the TIME data column to become number data format by using this format 'hh:mm:ss' because it is a string data format which cannot be able to be converted to number format by me. I have tried so many times by using that c variable (str2double(strrep(TIME,':',''))) and the other, but it doesnt work. So please help me out everyone, thank you very much.
If the string formatted TIME data column had been converted to become number format (hh:mm:ss) so then i can plot it....
采纳的回答
Why go through all that trouble?
filename = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/666885/abk198911dmin.txt';
T = readtable(filename, 'headerlines', 12, 'variablenamingrule', 'preserve');
T.DT = T.DATE + T.TIME;
ABKX = T{:,4};
plot(T.DT, ABKX)
5 个评论
Tyann Hardyn
2021-6-27
Tyann Hardyn
2021-6-27
Walter Roberson
2021-6-27
Which MATLAB version are you using? I suspect that it might be older than the variablerenamingrule option, but if so then it might also be older than duration parsing.
Tyann Hardyn
2021-6-28
Walter Roberson
2021-6-28
in that case I think you can just remove the 'variablerenamingrule' option.
更多回答（1 个）
Scott MacKenzie
2021-6-27
No need to use textscan. Just read the data into a MATLAB table. The 2nd column (TIME) will be treated as durations. You can then use the hours function to get the time as a number for plotting. Here's a quick demo:
f = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/666885/abk198911dmin.txt';
T = readtable(f);
head(T)
T.TIME(1:5)
hours = hours(T.TIME(1:5))
Output:
ans =
8×8 table
DATE TIME DOY ABKX ABKY ABKZ ABKF x_
__________ ________ ___ _____ ____ _____ _____ ___
1989-11-01 00:00:00 305 11575 746 51129 99999 NaN
1989-11-01 00:01:00 305 11575 747 51132 99999 NaN
1989-11-01 00:02:00 305 11576 750 51134 99999 NaN
1989-11-01 00:03:00 305 11576 749 51135 99999 NaN
1989-11-01 00:04:00 305 11575 750 51137 99999 NaN
1989-11-01 00:05:00 305 11572 752 51137 99999 NaN
1989-11-01 00:06:00 305 11583 753 51135 99999 NaN
1989-11-01 00:07:00 305 11579 751 51137 99999 NaN
ans =
5×1 duration array
00:00:00
00:01:00
00:02:00
00:03:00
00:04:00
hours =
0
0.016667
0.033333
0.05
0.066667
类别
在 帮助中心 和 File Exchange 中查找有关 Data Type Conversion 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
