ThingSpeak Data Analysis answer is always NaN

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'); 

Answer 1

[Christopher Stapels]

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.

[Nipuna]

Thanks for the answer it helped to identify the problem