How to retrieve data from a website?

Question

ARGY B 2019-8-14

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https://ww2.mathworks.cn/matlabcentral/answers/476142-how-to-retrieve-data-from-a-website

评论： the cyclist 2019-8-14

采纳的回答： the cyclist

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I would like to retrieve data from a webasite, and store them in a matrix of two columns (or in two vectors).

I tried this:

url = ('http://matroos/direct/get_series.php?loc=hoekvanholland&source=observed&unit=waterlevel&tstart=201908140000&tstop=201908150000');
data = urlread(url);

But the result is not..satisfying!

Is there a smarter function to use instead of urlread?

(I have attached a pic of the website)

Thanx!

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Answer 1

the cyclist 2019-8-14

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According to its documentation page, use of urlread is not recommended. It suggests using webread instead.

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Rik 2019-8-14

Your downloaded result is just a text file. There are probably line endings encoded in there (char 10 and/or 13), but you'll have to do the parsing yourself.

Also, I haven't yet seen a situation with http where urlread couldn't manage. For https it is generally better to use webread, but even then urlread will do fine. For situations like str2num I can understand why the use is discouraged, but for urlread and histc I can't really find the reason.

the cyclist 2019-8-14

You might want to read the webread options section. The default is 'auto", which will try to determine the output type set by the server's API. I guess you could try one of the other options, if you know how the output is intended to be formatted (e.g. JSON).

It's probably just that the site returns plain text. In that case, you'll need to parse it yourself. There is an example of that here.

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