Extract data from URL Human Mortality Database

Question

Melania 2013-9-26

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/88318-extract-data-from-url-human-mortality-database

评论： Melania 2013-9-26

采纳的回答： Cedric

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Hi!

I'm having trouble trying to extract data from mortality.org.

urldoc = urlread('http://email:passwor@www.mortality.org/hmd/PRT/STATS/Mx_1x1.txt');
Error using urlreadwrite (line 36)
Either this URL could not be parsed or the protocol is not supported.
Error in urlread (line 36)
[s,status] = urlreadwrite(mfilename,catchErrors,url,varargin{:});

Thanks,

Melânia

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Cedric 2013-9-26

Which version of MATLAB do you have?

Melania 2013-9-26

Matlab R2013a

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Answer 1

Cedric 2013-9-26

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https://ww2.mathworks.cn/matlabcentral/answers/88318-extract-data-from-url-human-mortality-database#answer_97883

编辑：Cedric 2013-9-26

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MATLAB doesn't support well authentication. If you have 2013a, you can try this workaround.

If not, save the following function written I guess by Andrew Janke:

 function [s,info] = urlread_auth(url, user, password)
 %URLREAD_AUTH Like URLREAD, with basic authentication
 %
 % [s,info] = urlread_auth(url, user, password)
 %
 % Returns bytes. Convert to char if you're retrieving text.
 %
 % Examples:
 % sampleUrl = 'http://browserspy.dk/password-ok.php';
 % [s,info] = urlread_auth(sampleUrl, 'test', 'test');
 % txt = char(s)
 % Matlab's urlread() doesn't do HTTP Request params, so work directly with Java
 jUrl = java.net.URL(url);
 conn = jUrl.openConnection();
 conn.setRequestProperty('Authorization', ['Basic ' base64encode([user ':' password])]);
 conn.connect();
 info.status = conn.getResponseCode();
 info.errMsg = char(readstream(conn.getErrorStream()));
 s = readstream(conn.getInputStream());
 function out = base64encode(str)
 % Uses Sun-specific class, but we know that is the JVM Matlab ships with
 encoder = sun.misc.BASE64Encoder();
 out = char(encoder.encode(java.lang.String(str).getBytes()));
 function out = readstream(inStream)
 %READSTREAM Read all bytes from stream to uint8
 try
    import com.mathworks.mlwidgets.io.InterruptibleStreamCopier;
    byteStream = java.io.ByteArrayOutputStream();
    isc = InterruptibleStreamCopier.getInterruptibleStreamCopier();
    isc.copyStream(inStream, byteStream);
    inStream.close();
    byteStream.close();
    out = typecast(byteStream.toByteArray', 'uint8'); %'
 catch err
    out = []; %HACK: quash
 end

and then execute

 url    = 'http://www.mortality.org/hmd/PRT/STATS/Mx_1x1.txt' ;
 user   = 'yourLogin' ;
 pwd    = 'yourPassword' ;
 buffer  = char( urlread_auth( url, user, pwd )) ;

You can write buffer to file using e.g. FWRITE. You can also generate url dynamically using SPRINTF if you want to loop over files.

EDIT: you could actually extract the data on the fly, and save a .mat file instead of a text file. For example..

 % The two following replacements should be fine tuned to your needs.
 buffer = strrep(buffer, '+', ' ') ;         % Eliminate + ..
 buffer = strrep(buffer, ' .', '-1') ;       % Replace . entries with -1 ..
 % Txt -> cell array of num columns.
 data = textscan(buffer, '%f %f %f %f %f', Inf, 'HeaderLines', 3) ;

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Answer 2

Image Analyst 2013-9-26

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https://ww2.mathworks.cn/matlabcentral/answers/88318-extract-data-from-url-human-mortality-database#answer_97875

Does it change all the time, such that you need to read it in dynamically via MATLAB? If not, then just download it to a local file via your browser then have MATLAB use the local file instead.