How to Display certain time period of data

HI How can I disply certain data in thingspeak graph rather than display all data with time.

for example If the data start receiving from 10:00 to 11:00 AM , I need to see the data from 10:10AM-10:15AM (how can I make zoom to see only this part and disply it in the graph)?

Regards;

khalid

Answer 1

[Kiran Felix Robert]

Hi Khalid,

I assume that you are using thingSpeakRead function to read data from a ThingSpeak channel.

You can use following function syntax to obtain the timestamp along with the data. Refer the Documentation of thinkSpeakRead for examples.

[data,timestamps] = thingSpeakRead(__)

You can use logical comparisons on the timestamp data to plot the data from specific time intervals.

The following is an example.

 [data,timestamps,channelInfo] =   thingSpeakRead(12397,'Fields',[1,4],'NumMinutes',5);
 t = datestr(timestamps);
 HH = str2num(t(:,13:14)); % Hour
 MM = str2num(t(:,16:17)); % Minutes
 x = (HH == 10 & MM > 00 & MM <= 15);  % Range of data to be plotted
 % Plots data between 10:00 AM and 10:15 AM
 plot(timestamps(x),data(x))

Answer 2

[Niall]

I've a cheekier solution to this than Kiran has posted. Simply use the datetime function as limits for the plot. I'm using the same assumption that you're using a matlab vizualisation.

[vibration, time] = thingSpeakRead(readChannelID, 'Field', fieldID1, 'NumPoints', 1000, 'ReadKey', readAPIKey);
% t = datetime(Y,M,D,H,MI,S)
tmin = datetime(2021,5,6,13,48,0);
tmax = datetime(2021,5,6,13,57,0);
plot(time, vibration);
xlim([tmin tmax])