IoT Data Explorer for ThingSpeak and MATLAB

I am unable to get the Visualization plot. I am getting this "Not enough fields selected" error window. I am using the Online Matlab. The Thingspeak Channel ID is 1829694 and the ReadAPIKy is "VZK8QZDLZQBQPBUQ". There are 1000 entries in each of the 6 fields from 7/2/2023 9.58 PM to 14/2/2023 9.11 PM.

I tried various dates for selecting the data range but unable to get the plot. kindly suggest to get the plot.

Answer 1

[Christopher Stapels]

The app was made assuming you have a relatively continuous data stream. Your data is very sparse with respect to time. I was able to get it to work with the properties shown in the picture here, since you have more regular data over this range (today). If either the section you select for comparison or the base region is empty of data, the comparison will fail. Thanks for the feedback on the app though! Ill have to think how to accommodate your use case given the architecture I’ve used in the app. The code is there in File Exchange though, so feel free to suggest a good solution if you have one.

[Syed]

I really appreciate your response. I tried with the SAME properties shown in the picture that you sent. But I still face the same issue i.e. "Not enough fields selected" error window.

[Christopher Stapels]

It could be your timezone? MATLAB will read data into your own timezone. What I did to get it working was to read you data into MATLAB and look at the timestamps. Then I chose the time in the app to see your data. Both the range you request in the app and the range that is comparing to need to have data.

Can you tell me about your final goal? Are you exploring the app, or exploring your data, or getting ready to create improvements to the app? If you are testing the app, i suggest reading data from a public channel (like the traffic monitor channel).

If you are trying to view your specific data, I think you could use MATLAB until you get data that is regular over a longer period.

[Syed]

I am exploring my data. As you suggested, I'll try to use MATLAB until I get data that is regular over a longer period. Thanks

[Syed]

Just to observe the graph or you can say to test the output of your app, I tried to use your app to read data from a public channel (Traffic monitor). Still I am not able to get the plot. I'm getting the same error. Where am I doing wrong? Is it due to the online Matlab software that I am using or something else? Kindly guide. I want to see that your app is working from my side.

[Christopher Stapels]

oh wow, are you running on MATLAB online? I wrote that app before we could test in MATLAB online. Ill definitely try it soon. I've been testing in desktop MATLAB. I'm glad to hear you are trying it out, sorry its not working out of the box. Let me know if you get anywhere looking at it in debug mode in appdesigner before I get a chance.

[Christopher Stapels]

I got it to work in MATLAB online, though I wasnt able to debug in app designer in MATLAB online. Here are my settings.

[Syed]

Dear Christopher, sorry to say. Still I am facing with the same problem i.e "Not enough Fields selected" even for the public channel. I put the same properties as shown in your figure. I even tried by toggling the time stamp (AM as well as PM).

[Christopher Stapels]

Thanks so much for sticking with me on this. Its a strange bug. I just double checked on a second computer using MATLAB online and it works. If you have any more time to work on this, can you try opening the app in appdesigner? I found you need to 'save as' locally in your MATLAB drive in order to debug it. If that works, I can show you where to put break points to see why there is no data being returned.

[Syed]

Yes Christopher, I am able to open n AppDesigner