Importing and Analyzing .txt files

How can I import multiple files into matlab and then for example only get data from certain columns and certain parts of that column? For example I could have a .txt file with 1,000 lines and 3 columns (date, flowrate1,flowrate2). The dates range from jan-dec and I only want to import data from columns 2,3 (flowrate1,flowrate2) from the month of March?

[dpb]

Just read the full file and then select the subset of data wanted...if you only import the flow data, you don't have the date data from which to select.

One good way would be to use detectimportoptions first, then use that object with readtable and it most likely will be able to automagically import the date column as datetime which is easy to use to select dates within ranges.

Answer 1

[Walter Roberson]

https://www.mathworks.com/help/matlab/ref/timerange.html

You can use readtable() and convert to timetable() objects, and use timerange() indexing.

Alternately, you can use readtable(), and use month() on the date column, and compare the result to 3 in order to get a mask for which rows to use. Note that this would find all March items from separate years if there are multiple years in the file.