subsetting a matrix by date in matlab

Suppose you have a matrix A with N rows and M columns, and a vector of dates dates with N elements, you can subset matrix A based on a date range using the following code:

main.m
% define date range of interest
date_start = datetime(2022, 1, 1); % start date
date_end = datetime(2022, 6, 30); % end date

% find indices of dates within range
idx = dates >= date_start & dates <= date_end;

% subset matrix A based on indices
A_subset = A(idx,:);
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This code creates a logical index of N elements, where true indicates the corresponding date is within the range defined by date_start and date_end. Then, this index is used to subset matrix A. The resulting A_subset will have only the rows corresponding to the dates within the specified date range.

Note that the dates must be represented in MATLAB's datetime format for this method to work. If your dates are represented as strings or as MATLAB serial date numbers, you will need to convert them to datetime first using datenum or datetime functions.

Also note that this method assumes the dates vector is a column vector of the same length as the number of rows in A. If your dates vector is a row vector, you will need to transpose it using dates' to make it a column vector.