MATLAB: Extract rainfall values and the corresponding date from a time series when it satisfies certain condition

data analysisdata pre-processingfor loop

I have a daily time series data of one rain gauge station for 113 years. I want to extract those rainfall values and the corresponding dates only for those rainfalls which have a value greater than 2.5 mm and count the number of days with rainfall values greater than 2.5 mm for each year. The data is in .xlsx format and sample data is attached here.
Any help will be highly appreciated.

Best Answer

This required a few extra lines because the original date strings didn’t have uniform formats (so the regexp call).
This works:
[d,s,r] = xlsread('martin atam Rainfall.xlsx');
rain = d;                                                                       % Daily Rainfrall
dc = regexp(s, {'/|-'}, 'split');                                               % Pares Dates
dm = cellfun(@(x)sprintf('%2s/%2s/%4s\n', x{:}), dc, 'UniformOutput',false);    % Uniform Date Strings
dn = datenum(dm, 'dd/mm/yyyy');                                                 % Date Numbers
% dns = datestr(dn(1:15))                                                         % Check Conversion (Optional)
rain25idx = rain > 2.5;                                                         % Logical Index Vector
rain_dv = datevec(dn(rain25idx));                                               % Rain Day Years
[Uyr,ia,ic] = unique(rain_dv(:,1), 'stable');                                   % Create Indices (‘ic’) To Tally
hc = accumarray(ic, 1);                                                         % Count Rain Days By Year
Out = [Uyr, hc];                                                                % Years & Rain Days
Out_Check = Out(1:10,:)                                                         % Sample Output (Optional)
Out_Check =
          1901          88
          1902         106
          1903          77
          1904          67
          1905          93
          1906          92
          1907         113
          1908          89
          1909          92
          1910          86
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