Show temperature difference (delta) between 2 temps in a graph

Hi peeps, new to matlab, i want to show in my channel a graph showing the delta difference between 2 temperatures as a bar graph, so its easy to see where the difference is not optimal for my heat pump, ie between 4 and 5 degrees c.

Can anyone help with some sample code pls?

ta

steve

[the cyclist]

% Make up some data. (Use your real data instead)
rng default
T1 = rand(1,7);
T2 = rand(1,7);

plot(T2-T1)

Now, explain why that doesn't work for you, and I'll explain that you should have given us a lot more detail in your original question. :-)

[Steven Langston]

Cool, i must learn some code in matlab! Itd be nice to anotate 11pm 4am and other bits. Another language to learn lol

% Enter your MATLAB code below
% Channel ID to read data from 
readChannelID = 123456; 
% Channel Read API Key   
% If your channel is private, then enter the read API 
% Key between the '' below:   
readAPIKey = ''; 
% Read Temperature Data. Learn more about the THINGSPEAKREAD function by 
% going to the Documentation tab on the right side pane of this page. 
temperaturefield1 = thingSpeakRead(readChannelID,'Fields',2,'NumMinutes', 360); 
temperaturefield2 = thingSpeakRead(readChannelID,'Fields',5,'NumMinutes', 360); 
bar(temperaturefield1-temperaturefield2)

Answer 1

[Steven Langston]

What id like to do here, is to super impose a average of the these peaks and draw a line across and also show in digits in the space to the top right of the graph the figure of this average.

Something like this - (but i havent added a figure, in the left graph it shold say 4.8C and in the right hand one, about 9.8C)

Any pointers?

Cheers

Steve

Answer 2

[the cyclist]

Here is an example similar to what posted in my comment, but added line and text:

rng default

x = rand(1,5);
mean_x = mean(x);

figure
bar(x)
yline(mean_x,'r')
text(0.05,0.95,sprintf('Mean x value is %7.3f',mean_x))

You can read the documentation of all the commands I used, to see more details on how to use MATLAB. This forum is really the best for learning MATLAB from the ground up. I would suggest watching the MATLAB Onramp tutorial, and perhaps take a look at the code in the MATLAB Plot Gallery for ideas on making different types of plot.

[Steven Langston]

thanks for that, this ideal for watching during my exercise (stepping), 20mins a time!

Answer 3

[Steven Langston]

getting somewhere but cant find much guid on how to ignore values below say 3c and above 6c?

[the cyclist]

% Example temperature input
T = [1 2 3 4 5 6 7 8];

% True/false vector corresponding to elements greater than 3
T > 3

ans = 1×8 logical array
   0   0   0   1   1   1   1   1

% True/false vector corresponding to elements greater than 3 and less than 6
(T>3) & (T<6)

ans = 1×8 logical array
   0   0   0   1   1   0   0   0

% The elements of T that are >3 and <6
T((T>3) & (T<6))

ans = 1×2

4 5