Facing problem with the error ''Expected a string scalar or character vector for the parameter name''

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Tanusree 2024-4-30

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2113311-facing-problem-with-the-error-expected-a-string-scalar-or-character-vector-for-the-parameter-name

移动：Stephen23 2024-4-30

Everytime I want to execute the following programming on ThingSpeak Matlab Analysis, facing problem with thingSpeakWrite, and it is showing ''Expected a string scalar or character vector for the parameter name'' error.

Also how can I write every data instead of single data to write channel on ThingSpeak?

% Read the most recent data from the source channel
data = thingSpeakRead(readChannelID, 'ReadKey', readAPIKey, 'Fields', [1, 2], 'NumPoints', 7);
% Extract the values from the read data
values1 = data(:, 1) % Values from field 1
values2 = data(:, 2) % Values from field 2
% Write the data to the destination channel
thingSpeakWrite(writeChannelID, 'WriteKey', writeAPIKey, [values1, values2], 'Fields', [1, 2]);

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Tanusree 2024-4-30

在 MATLAB Online 中打开

I changed the programming to discard the NAN values from read channel and only write the remaining datas instead of single data as follows but still it is showing the same error ''Expected a string scalar or character vector for the parameter name'' .

% Find rows containing NaN values and remove them
nanRows = any(isnan(data), 2);
dataWithoutNaN = data(~nanRows, :);
% Loop through each row of data (excluding the first row with NaN values)
for i = 2:size(dataWithoutNaN, 1)
    % Extract values from the current row
    rowValues = dataWithoutNaN(i, :);
    
    % Convert rowValues to cell array for compatibility with thingSpeakWrite
    rowData = num2cell(rowValues);
    
    % Write the current row to the destination channel
    thingSpeakWrite(writeChannelID, 'WriteKey', writeAPIKey, 'Fields', [1, 2], rowData{:});
    
    % Pause for a short interval to avoid exceeding ThingSpeak API rate limits
    pause(2); % Adjust the interval as needed
end

Stephen23 2024-4-30

移动：Stephen23 2024-4-30

在 MATLAB Online 中打开

thingSpeakWrite(writeChannelID, 'WriteKey', writeAPIKey, 'Fields', [1, 2], rowData{:});
%        this comma-separated list does not produce valid name-value pairs ^^^^^^^^^^

Making random changes is less efficient than following the documentation:

https://www.mathworks.com/help/matlab/ref/thingspeakwrite.html

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