Resultados de
% Sample data from channels
channel1Data = 2226948; % Your data for channel 1
% Threshold values for each alert level
threshold1 = 100;
threshold2 = 200;
threshold3 = 300;
% Initialize alert level to 0 (no alert)
alertLevel = 0;
% Check thresholds and determine alert level
if channel1Data >= threshold1 && channel1Data <= threshold2
alertLevel = 1; % Yellow Alert
elseif channel1Data >= threshold2 && channel1Data <= threshold3
alertLevel = 2; % Orange Alert
elseif channel1Data >= threshold3
alertLevel = 3; % Red Alert
end
% Define alert message based on alert level
if alertLevel == 1
alertMessage = 'Threshold exceeded for channel 1!';
elseif alertLevel == 2
alertMessage = 'Threshold exceeded for channel 2!';
elseif alertLevel == 3
alertMessage = 'Threshold exceeded for channel 3!';
else
alertMessage = 'No alert for channel 1.';
end
% Call SMS integration function with the alert message
sendMessage('+639319217695', alertMessage);
function sendMessage(number, message)
% Replace with your SMS service API endpoint and API key
apiUrl = 'https://api.semaphore.co/api/v4/messages';
apiKey = '-----';
% Compose the message payload
payload = struct('apikey', apiKey, 'number', number, 'message', message);
try
% Send the SMS using the SMS service API
response = webwrite(apiUrl, payload);
% Process the response as needed
disp('SMS sent successfully');
catch
disp('Error sending SMS');
end
end
Summary:
Dynamically accessing variable names can negatively impact the readability of your code and can cause it to run slower by preventing MATLAB from optimizing it as well as it could if you used alternate techniques. The most common alternative is to use simple and efficient indexing.
Explanation:
Sometimes beginners (and some self-taught professors) think it would be a good idea to dynamically create or access variable names, the variables are often named something like these:
- matrix1, matrix2, matrix3, matrix4, ...
- test_20kmh, test_50kmh, test_80kmh, ...
- nameA, nameB, nameC, nameD,...
Good reasons why dynamic variable names should be avoided:
- Slow
- Buggy
- Security Risk
- Difficult to Work With
- Obfuscated Code Intent
- Confuses Data with Code
- Code Helper Tools do not Work
- Magically Making Variables Appear in a Workspace is Risky
There are much better alternatives to accessing dynamic variable names:
- Indexing into Cell Array or ND-Array
- Non-scalar Structures (with Indexing)
- Dynamic Field-Names in a Structure
- load into a Structure, not into the Workspace
- save the Fields of a Scalar Structure
- Use a table or timetable Array
- Use more Efficient Ways to Pass Variables Between Workspaces
Note that avoiding eval (and assignin, etc.) is not some esoteric MATLAB restriction, it also applies to many other programming languages as well:
MATLAB Documentation:
If you are not interested in reading the answers below then at least read MATLAB's own documentation on this topic Alternatives to the eval Function, which states "A frequent use of the eval function is to create sets of variables such as A1, A2, ..., An, but this approach does not use the array processing power of MATLAB and is not recommended. The preferred method is to store related data in a single array." Data in a single array can be accessed very efficiently using indexing.
Note that all of these problems and disadvantages also apply to functions load (without an output variable), assignin, evalin, and evalc, and the MATLAB documentation explicitly recommends to "Avoid functions such as eval, evalc, evalin, and feval(fname)".
The official MATLAB blogs explain why eval should be avoided, the better alternatives to eval, and clearly recommend against magically creating variables. Using eval comes out at position number one on this list of Top 10 MATLAB Code Practices That Make Me Cry. Experienced MATLAB users recommend avoiding using eval for trivial code, and have written extensively on this topic.
