ThingSpeak Data Analysis answer is always NaN

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Nipuna on 5 Jul 2020
Commented: Nipuna on 6 Jul 2020
When I use following code the answer I receive is always
Average Humidity = NaN
What is the reason? Is there a way to set data type in Channel fields?
readChannelID = 1094383;
% Humidity Field ID
humidityFieldID = 1;
% Channel Read API Key
% If your channel is private, then enter the read API Key between the '' below:
readAPIKey = 'xxxxxxxxxxxxxx'; %removed the API key
% Get humidity data for the last 60 minutes from the MathWorks weather
% station channel. Learn more about the THINGSPEAKREAD function by going to
% the Documentation tab on the right side pane of this page.
humidity = thingSpeakRead(readChannelID,'Fields',humidityFieldID,'NumMinutes',120,'ReadKey',readAPIKey);
% Calculate the average humidity
avgHumidity = mean(humidity);
display(avgHumidity,'Average Humidity');

Answers (1)

Christopher Stapels
Christopher Stapels on 6 Jul 2020
If there is no data in the last 120 minutes, this will return empty, and make the average NaN.
humidity = thingSpeakRead(readChannelID,'Fields',humidityFieldID,'NumMinutes',120,'ReadKey',readAPIKey);
You could add a line to check humitidy to be sure there was data read before calculating the average, or increase the time range.
  1 Comment
Nipuna on 6 Jul 2020
Thanks for the answer it helped to identify the problem

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