my code is not running

for year = 2009:2017
 year index = year-2008
 year struct = load( [ 'D:\DataStation\hr ',num2str(ye), '\mat\station.mat' ] );
for station = 1:30
  eval ( [ "station double = year struct.station_',num2str(station),';'] );
    station double = station double (1:8760,:);
      data(:,:,station,year) = station double
end
end

Answer 1

[Chunru]

This is my best guess.

for year = 2009:2017
    year_index = year-2008    % no space in variable names
    year_struct = load( [ 'D:\DataStation\hr ',num2str(year), '\mat\station.mat' ] );
    for station = 1:30
        eval ( ['station_double = year_struct.station_', num2str(station), ';'] );
        station_double = station_double (1:8760,:);
        data(:, :, station, year_index) = station_double;
    end
end

Answer 2

[Image Analyst]

This is how I'd do it:

for theYear = 2009:2017
	yearIndex = theYear-2008;    % no space in variable names
	fullFileName = sprintf('D:/DataStation/hr %d/mat/station.mat', theYear);
	if isfile(fullFileName)
		% Load .mat file into a structure.
		yearStruct = load(fullFileName);
		% Get all the field names 'station_1', 'station_2', etc. into a cell array
		fn = fieldnames(yearStruct);
		for station = 1 : length(fn)
			% Get this particular field name.
			thisFieldName = fn{station};
			% Get the 2-D array in this field.
			thisMatrix = yearStruct.(thisFieldName);
			% Crop out part of it.
			station_double = thisMatrix (1:8760,:);
			% Add this matrix to our 4-D array.
			data(:, :, station, yearIndex) = station_double;
		end
	else
		warningMessage = sprintf('Warning: file not found:\n%s', fullFileName);
		uiwait(warndlg(warningMessage));
	end
end