Downloading Data off a URL and specifying what portion of the URL to save.

Question

Christopher Locke 2015-9-14

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/242927-downloading-data-off-a-url-and-specifying-what-portion-of-the-url-to-save

编辑： Kleber Zuza Nobrega 2016-4-6

I am trying to take Data off 'http://tidesandcurrents.noaa.gov/harcon.html?id=9410170' and upload it to arrays. The problem that I am running into is whenever I websave or webread the URL the entire code comes up. I want to only download and save the Constituent #, Name, Amplitude, Phase, Speed, and Description portion of the URL and have MatLab display those variables separately as arrays, to be used later on.

2 个评论
显示无隐藏无

Kleber Zuza Nobrega 2016-4-6

Try this: pattern='<dt>Constituent #</dt>\s*<dd>(?<Cons>.*?(</dd>)?)\s*<dt>Name</dt>\s*<dd>(?<Nam>.*?)</dd>\s*<dt>Amplitude</dt>\s*<dd>(?<Amp>.*?)</dd>\s*<dt>Phase</dt>\s*<dd>(?<Pha>.*?)</dd>\s*<dt>Speed</dt>\s*<dd>(?<Spe>.*?)</dd>\s*<dt>Description</dt>\s*<dd>(?<Des>.*?)</dd>'

res=regexp(code,pattern,'names')

res.Cons %to have access to the text!! and so on res.Nam res.Amp res.Pha res.Spe res.Des

Kleber Zuza Nobrega 2016-4-6

编辑：Kleber Zuza Nobrega 2016-4-6

code=webread('http://tidesandcurrents.noaa.gov/harcon.html?id=9410170')

pattern='<td>(.*?)</td><td>(.*?)</td><td>(.*?)</td><td>(.*?)</td><td>(.*?)</td><td>(.*?)</td>'

res=regexp(code,pattern,'tokens')

Sorry... Misunderstood. Try this!!

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Tim Jackman 2015-9-16

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/242927-downloading-data-off-a-url-and-specifying-what-portion-of-the-url-to-save#answer_192598

Webread is designed for RESTful web services, so using it here isn't going to be ideal. You could parse the html code and grab information from the table between the thead and tbody tags, but I'd recommend giving one of these from the File Exchange a try:

http://www.mathworks.com/matlabcentral/fileexchange/22465-get-html-table-data-into-matlab

http://www.mathworks.com/matlabcentral/fileexchange/29642-get-html-table-data-into-matlab-via-urlread-and-without-builtin-browser

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Robert Snoeberger 2015-10-26

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/242927-downloading-data-off-a-url-and-specifying-what-portion-of-the-url-to-save#answer_197413

编辑：Robert Snoeberger 2015-10-26

在 MATLAB Online 中打开

As Tim Jackman correctly pointed out, webread is designed for RESTful web services. Consuming an API provided by a web service will be much easier than screen scraping the data.

The tidesandcurrents.noaa.gov site does provide an API [1], which I found with a google search. The following is an example of using webread to read the data from the web service. The example is based on the "Sample URL requests and responses" section of the API documentation.

>> opts = weboptions('ContentType', 'json');
>> url = 'http://tidesandcurrents.noaa.gov/api/datagetter';
>> result = webread(url, opts, 'product', 'water_level', 'begin_date', '20130101', 'end_date', '20130101', 'station', '8454000', 'time_zone', 'gmt', 'units', 'metric', 'datum', 'mllw', 'format', 'json')
result = 
      metadata: [1x1 struct]
          data: [240x1 struct]
>> result.data(1)
ans = 
      t: '2013-01-01 00:00'
      v: '0.549'
      s: '0.004'
      f: '0,0,0,0'
      q: 'v'
>>