Matlab Analysis won't update my field!

Hi

I used this code to show last 20 field1 datas in field2 chart:

% Enter your MATLAB Code below
readChId = XXX;
readKey = 'XXXXX';
writeChId = YYY;  
writeKey = 'YYYYY'; 
[Data,t] = thingSpeakRead(readChId,'Fields',1,'NumPoints',20,'readkey',readKey);
thingSpeakWrite(writeChId,Data,'Fields',2,'Timestamps',t,'Writekey',writeKey);
display (Data)

when i click save an run i can see Data in output box but i can't see anything in field2 chart!

i activate timecontrol for every 30 minuts but still i can't see any data in field2 chart :(

what is my problem?

Answer 1

[Vinod]

If you want a plot of your values, you need to use a MATLAB visualization and add the output to the view of your channel.

[Esmaeil Chehrehnama]

i can't use timecontrol to matlab visualization while i want to update my plot

so how can i update my matlabvisualization plot automatically?

[Vinod]

The MATLAB visualization auto updates if you have a paid ThingSpeak license. Also, it auto updates when the channel page is loaded if it has been 5 minutes since it was last updated.

[Esmaeil Chehrehnama]

Thank u for your answer. So what does the function "thingSpeakWrite" in Matlab Analysis do? Doesn't it write Data on my field?

[Esmaeil Chehrehnama]

Actually I am looking for a way to show only the last 20 data or the last 30 minuts of data on my field! How can i do that?

[Christopher Stapels]

thingSpeakRead(12397,'NumMinutes',20);