Why is this happening in this code?

Question

alpedhuez 2022-3-12

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1670004-why-is-this-happening-in-this-code

评论： alpedhuez 2022-3-12

I run the code from https://www.mathworks.com/matlabcentral/answers/1646135-downloading-files-from-a-website-with-conditions-on-names-of-files?s_tid=srchtitle with the modification from a previous question:

baseurl = "https://www.somecompany.com/xml/";
datelimits = datetime({'20080401', '20080501'}, 'InputFormat', 'yyyyMMdd','Format','yyyyMMdd');
subfile_limit = 5;  %no more than _5 -- adjust as appropriate
subfile_modifier = ["", "_" + (1:subfile_limit)] + ".xml";
for Day = datelimits(1):datelimits(2)
    daystr = string(Day);
    for Sub = subfile_modifier
        filename = "A_" + daystr + Sub;
        url = baseurl + filename;
        try
            outfilename = websave(filename,url);
            fprintf('fetched %s\n', filename);
        catch
            break;  %skip remaining subfiles for this date upon first failure
        end
    end
end

Then I got the following value for "subfile_modifier"

https://imgur.com/a/mRciGL2

But the following for "Sub"

https://imgur.com/a/qvgWwro

I do not understand why "_' + (1:subflie_limit) part is missing. Please advise.

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Answer 1

Cris LaPierre 2022-3-12

0
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1670004-why-is-this-happening-in-this-code#answer_915964

在 MATLAB Online 中打开

The ".xml" corresponds to the "" in your submifle_modifier.

subfile_limit = 5;
subfile_modifier = ["","_" + (1:subfile_limit)] + ".xml"
subfile_modifier = 1×6 string array
    ".xml"    "_1.xml"    "_2.xml"    "_3.xml"    "_4.xml"    "_5.xml"

If you do not want to use that extension, then remove the "".

subfile_modifier = ["_" + (1:subfile_limit)] + ".xml"
subfile_modifier = 1×5 string array
    "_1.xml"    "_2.xml"    "_3.xml"    "_4.xml"    "_5.xml"