My matlab code is giving me this error "Too many outputs requested". If someone can help me solve this?

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Punit Gandhi 2015-4-5

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评论： Mohammad Abouali 2015-4-5

Hello, My code is as follows:

 %Create a vector with date and time
    c_forecast = clock
    %Put the integer vector values in strings
    year_forecast = int2str(c_forecast(1));
    month_forecast = int2str(c_forecast(2));
    day_forecast = int2str(c_forecast(3));
    hours_forecast = int2str(c_forecast(4));
    %Check if the month string has 1 or 2 digits (this is important for the
    %comparison of the julian date string)
    if size(month_forecast) == 1
        month_forecast = strcat('0',month_forecast);
    end
    %check if the day string has 1 or 2 digits.
    if size(day_forecast) == 1
        day_forecast = strcat('0',day_forecast);
        %month = strcat('0',day);
    end
       %nextday=[day add];
    %check if the hour string has 1 or 2 digits.
    if size(hours_forecast) == 1
        hours_forecast = strcat('0',hours_forecast);
    end
    % To be searched in xml file
    search_forecast=strcat(year_forecast,'-',month_forecast,'-',day_forecast,'T',hours_forecast,':00:00Z'); 
   %%Weather Data
   % Retrieving Cloud cover information from URL
   %cloud cover
     xdom = xmlread('http://api.met.no/weatherapi/locationforecast/1.9/?lat=53.05;lon=4.8;msl=1');
    cloudtags = xdom.getElementsByTagName('cloudiness');
    cloudiness_forecast = cell(cloudtags.getLength, 2); 
    for item = 1 : cloudtags.getLength
       cloudtag = cloudtags.item(item - 1);
       timetag = cloudtag.getParentNode.getParentNode;
       cloudiness_forecast{item, 1} = char(timetag.getAttribute('from'));
       cloudiness_forecast{item, 2} = str2double(cloudtag.getAttribute('percent'));
    end
    cloudiness_forecast;
     matchrow = strcmp(cloudiness_forecast(:, 1), search_forecast);
    cloud_forecast = cloudiness_forecast{matchrow, 2};
 When I try to run it, it gives me the following error:

Too many outputs requested. Most likely cause is missing [] around left hand side that has a comma separated list expansion.

Error in PowerCalculation cloud = cloudiness{matchrow, 2};

Can someone help me solve this problem. Thank you.

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Answer 1

Mohammad Abouali 2015-4-5

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编辑：Mohammad Abouali 2015-4-5

在 MATLAB Online 中打开

Don't know why cloud = cloudiness{matchrow, 2}; is causing too many output request error. Are you sure the error is for that line?

On the side note: If you want to have month 6 to be represented as 06 you can also use the following code:

month_forecast=sprintf('%0.2d',c_forecast(2))

The same goes for day. This is much more readable than those if-clauses.

Or you can rewrite the entire top part of your code as:

search_forecast=sprintf('%d-%0.2d-%0.2dT%0.2d:00:00:Z',c_forecast(1:4))

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Punit Gandhi 2015-4-5

Thank you for reducing the number of lines in my code.

Yes. The error is in this line itself according to the matlab.

Mohammad Abouali 2015-4-5

在 MATLAB Online 中打开

The problem is that all elements in matchrow are false. Meaning nothing matched the time string that you are looking for.

So change the code to check if there are any matching rows. Here is how the code changed:

%Create a vector with date and time
c_forecast = clock;
% To be searched in xml file
search_forecast=sprintf('%d-%0.2d-%0.2dT%0.2d:00:00:Z',c_forecast(1:4));
2015-04-15T12:00:00Z
%%Weather Data
% Retrieving Cloud cover information from URL
%cloud cover
xdom = xmlread('http://api.met.no/weatherapi/locationforecast/1.9/?lat=53.05;lon=4.8;msl=1');
cloudtags = xdom.getElementsByTagName('cloudiness');
cloudiness_forecast = cell(cloudtags.getLength, 2); 
for item = 1 : cloudtags.getLength
    cloudtag = cloudtags.item(item - 1);
    timetag = cloudtag.getParentNode.getParentNode;
    cloudiness_forecast{item, 1} = char(timetag.getAttribute('from'));
    cloudiness_forecast{item, 2} = str2double(cloudtag.getAttribute('percent'));
end
matchrow = strcmp(cloudiness_forecast(:, 1), search_forecast);
if (any(matchrow))
    cloud_forecast = cloudiness_forecast{matchrow, 2};
else
    disp('WARNING: Nothing matched.')
end