How to filter data?
1 次查看(过去 30 天)
显示 更早的评论
Dear all,
I want to filter a matrix by its date vector. The datevector has the format: dd.mm.yyyy HH:MM:SS. I want to sum up all the data with the same month and year. How can I do that?
0 个评论
采纳的回答
Jan
2013-1-16
dateAsString = {'31.02.2013 11:22:33'; '31.05.2013 11:22:33'}
dateAsVector = datevec(datestr, 'dd.mm.yyyy HH:MM:SS');
yearAndMonth = 100 * dateAsVector(:, 1) + dateAsVector(:, 2);
Now you get values like [201302, 201305] and summing can be done by accumarray directly.
2 个评论
Walter Roberson
2013-1-16
You would probably not want to use those values as direct subscripts into accumarray: you would probably want to unique() them and use the indices. Otherwise your array is going to end up being up to 240000 long with not many entries used.
Jan
2013-1-16
You are right, Walter, and even for a FOR loop approach using the indices obtained by UNIQUE is better.
更多回答(0 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Cell Arrays 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!