I am not able to do, sum of data of last 10 days, please help, it only displays data of 10 days. i want to add all the datas and display the total sum.

% Enter your MATLAB Code below
% Enter your MATLAB Code below
% Read Output Water Quantity over the past month from a ThingSpeak channel and write

% the average to another ThingSpeak channel.

% Channel 1035265 contains data from the MathWorks water supply station, located

% in Natick, Massachusetts. The data is collected once every day. Field

% 3 contains output liquid quantity data.

% Channel ID to read data from

readChannelID = 1035265;

% Output Liquid Quantity Field ID

outputliquidqantityFieldID = 3;

% Channel Read API Key

% If your channel is private, then enter the read API Key between the '' below:

readAPIKey = '';

% Get Output Liquid Quantity data for the last 30 days from the MathWorks water supply

% station channel. Learn more about the THINGSPEAKREAD function by going to

% the Documentation tab on the right side pane of this page.

meter_reading = thingSpeakRead(readChannelID,'Fields', outputliquidqantityFieldID,'NumDays',10,'ReadKey',readAPIKey);

% Calculate the Cost
Billing_cost = 5*(meter_reading/1000);
display(Billing_cost,'Total Billing Cost (INR)');

% Start by setting the channel ID and Alert key. All alert key start with TAK.

formatSpec = "The Water consumption bill is: %d,%d";
A1 = 5*(meter_reading/1000);
A2 = meter_reading
apiKey = 'TAK14ZOZGAXZQMR05';
alertURL = "https://api.thingspeak.com/alerts/send";
options = weboptions("HeaderFields", ["ThingSpeak-Alerts-API-Key", apiKey ]);
alertBody = sprintf(formatSpec,A1,A2)
alertSubject = sprintf(" Water consumption exceeded 100 l!");
if meter_reading >= 100
    webwrite(alertURL, "body", alertBody, "subject", alertSubject, options);
end 

[dpb]

Does

meter_reading = thingSpeakRead(readChannelID,'Fields', outputliquidqantityFieldID,'NumDays',10,'ReadKey',readAPIKey);

return 10 values I presume?

If so, why doesn't sum(meter_reading) serve the purpose?

[Aman Kumar]

I tried sum(meter_reading), it still displays all the entries of 10 days. Dosen't display the sum total of all entries.

[KALYAN ACHARJYA]

whos meter_reading?

[Christopher Stapels]

sum(meter_reading) worked for me. THere were 64 values, summing to 49321.