问基于MATLAB的DJing (低电平I/O)

EN

function [song] = pickSong(file_name, time_remain)

% // Open up the file
fid = fopen(file_name, 'r');

%// Read the first line
song_name = fgetl(fid);

%// Initialize cell array
song_list = {song_name};

%// Read in the song list and place
%// each entry into a cell array
while ischar(song_name)
    song_name = fgetl(fid);
    if song_name == -1
        break;
    end
    song_list = [song_list {song_name}];
end

%// Now, for each entry in our song list, find all occurrences of the '-'
%// with strfind, and choose the last index that '-' occurs at
%// Make sure you skip over by 2 spaces to remove the '-' and the space
song_times = cell(1,length(song_list));
song_names = cell(1,length(song_list));
for idx = 1 : length(song_list)
    idxs = strfind(song_list{idx}, '-');
    song_times{idx} = song_list{idx}(idxs(end)+2:end);

    idxs2 = strfind(song_list{idx}, ' ');
    %// Figure out the index of where the first space is, then extract
    %// the string that starts from 1 over, to two places before the 
    %// last '-' character
    song_names{idx} = song_list{idx}(idxs2(1)+1 : idxs(end)-2);
end

%// Now we have a list of times for each song.  Tokenize by the ':' to 
%// separate the minutes and times, then calculate the number of seconds
%// Logic borrowed by MrAzzaman
song_seconds = zeros(1,length(song_list));
for idx = 1 : length(song_list)
    [minute_str, second_str] = strtok(song_times{idx}, ':');
    song_seconds(idx) = str2double(minute_str)*60 + str2double(second_str(2:end));
end

%// Now, calculate how much time is remaining from the input
[minute_str, second_str] = strtok(time_remain, ':');
seconds_remain = str2double(minute_str)*60 + str2double(second_str(2:end));

%// Now, choose the song that is closest to the amount of time
%// elapsed
[~,song_to_choose] = min(abs(seconds_remain - song_seconds));

%// Return the song you want
song = song_names{song_to_choose};

%// Close the file
fclose(fid);

end

>> song1 = pickSong('Funeral.txt', '3:13')

song1 =

Neighborhood #2 (Laika)

>> song2 = pickSong('Resistance.txt', '3:57')

song2 =

Exogenesis: Symphony Part 2 (Cross-Pollination)

function song = pickSong(filename, time_remain)
    % read songs file into a table
    t = readSongsFile(filename);

    % query song length (in seconds)
    len = str2double(regexp(time_remain, '(\d+):(\d+)', ...
        'tokens', 'once')) * [60;1];

    % find closest match
    [~,idx] = min(abs(t.Duration - len));

    % return song name
    song = t.Title(idx);
end

function t = readSongsFile(filename)
    % read the whole file (as a cell array of lines)
    fid = fopen(filename,'rt');
    C = textscan(fid, '%s', 'Delimiter',''); C = C{1};
    fclose(fid);

    % parse lines of the form: "0. some name - 00:00"
    C = regexp(C, '^(\d+)\.\s+(.*)\s+-\s+(\d+):(\d+)$', 'tokens', 'once');
    C = cat(1, C{:});

    % extract columns and create a table
    t = table(str2double(C(:,1)), ...
        strtrim(C(:,2)), ...
        str2double(C(:,3:4)) * [60;1], ...
        'VariableNames',{'ID','Title','Duration'});
    t.Properties.VariableUnits = {'', '', 'sec'};
end

>> pickSong('Funeral.txt', '3:13')
ans = 
    'Neighborhood #2 (Laika)'

>> pickSong('Resistance.txt', '3:57')
ans = 
    'Exogenesis: Symphony Part 2 (Cross-Pollination)'

>> t = readSongsFile('Funeral.txt');
>> t.Minutes = fix(t.Duration/60);       % add minutes column
>> t.Seconds = rem(t.Duration,60);       % add seconds column

>> sortrows(t, 'Duration', 'descend')    % show table sorted by duration
ans = 
    ID                Title                Duration    Minutes    Seconds
    __    _____________________________    ________    _______    _______
    10    'In the Backseat'                381         6          21     
     7    'Wake Up'                        339         5          39     
     4    'Neighborhood #3 (Power Out)'    312         5          12     
     9    'Rebellion (Lies)'               310         5          10     
     5    'Neighborhood #4 (7 Kettles)'    289         4          49     
     1    'Neighborhood #1 (Tunnels)'      288         4          48     
     6    'Crown of Love'                  282         4          42     
     8    'Haiti'                          247         4           7     
     3    'Une annee sans lumiere'         220         3          40     
     2    'Neighborhood #2 (Laika)'        213         3          33    

% find songs that are at least 5 minutes long
>> t(t.Minutes >= 5,:)

% songs with the word "Neighborhood" in the title
>> t(~cellfun(@isempty, strfind(t.Title, 'Neighborhood')),:)

function[song,len] = pickSong(file_name,time_remain)

fid = fopen(filename);

toks = textscan(fid,'%[^-] - %d:%d');
songs = toks{1};
song_len = double(toks{2}*60 + toks{3});

[min_rem, sec_rem] = strtok(time_remain, ':');
time_rem = str2double(min_rem)*60 + str2double(sec_rem(2:end));

[len,i] = min(abs(time_rem - song_len));
song = songs{i};

function[song,len] = pickSong(file_name,time_remain)

file = fileread(file_name);
toks = regexp(file,'\d+. (.*?) - (\d+):(\d+)\n','tokens');
songs = cell(1,length(toks));
song_lens = zeros(1,length(toks));
for i=1:length(toks)
    songs{i} = toks{i}{1};
    song_lens(i) = str2double(toks{i}{2})*60 + str2double(toks{i}{3});
end

[min_rem, sec_rem] = strtok(time_remain, ':');
time_rem = str2double(min_rem)*60 + str2double(sec_rem(2:end));

[len,i] = min(abs(time_rem - song_lens));
song = songs{i};

match n digits, followed by a (string), followed by (n-digits):(n-digits)