Plotting (threshold, peaks etc.) in Signal Analyzer App

Hello everybody out there using MATLAB,

Despite doing elaborate analyzes by coding with text, I like the Signal Analyzer App for visual exploration of a signal.

However, I quickly hit the limits of what is offered by the GUI and was wondering, whether there is a convenient way to plot a certain threshold as a line, to put labels at the output of the findpeaks functions etc.

Answer 1

[Umar]

Hi Priesemut,

It's great to hear that you are utilizing the Signal Analyzer App for signal exploration. To address your specific needs beyond the GUI limitations, there are several ways you can enhance your analysis within MATLAB.

Plotting a Threshold Line: You can easily plot a threshold line on your signal plot by using the `yline` function in MATLAB. Simply specify the threshold value as an argument to `yline` to add a horizontal line at that level on your plot. This can help visualize certain thresholds and make it easier to interpret your data. For example,

>> % Define your threshold value threshold = 0.5;

% Define or load your signal data signal = [0.1, 0.3, 0.6, 0.4, 0.7];

% Plot your signal plot(signal); hold on;

% Add a threshold line yline(threshold, 'r--', 'Threshold');

Please see attached plot.

Adding Labels at Findpeaks Output: If you want to label the peaks detected by the `findpeaks` function, you can use the `text` function in MATLAB to add text annotations at specific data points on your plot. This can provide additional context to your analysis and make it easier to identify key features in your signal. For example,

>> % Define a sample signal signal = [1, 2, 3, 2, 5, 2, 1, 6, 2, 1];

% Find peaks in the signal [peaks, locs] = findpeaks(signal);

% Plot the signal plot(signal); hold on;

% Add labels at peak locations for i = 1:length(peaks) text(locs(i), peaks(i), num2str(peaks(i)), 'VerticalAlignment', 'bottom'); end

Please see attached plot.

By incorporating these techniques into your MATLAB workflow, you can overcome the limitations of the Signal Analyzer App's GUI and enhance your signal analysis with custom visualizations and annotations.

I hope this helps you take your signal analysis to the next level! Let me know if you have any more questions or need further assistance.

[Priesemut]

Thanks, this works of course for standard plots. I was wondering whether I can insert the threshold line or the peaks into the Signal Analyzer App.

Answer 2

[Umar]

Hi Priesemut,

You can indeed add threshold lines or highlight peaks within the Signal Analyzer App. Here's a step-by-step guide to help you accomplish this:

1. Open the Signal Analyzer App in MATLAB. 2. Load your signal data into the app by importing your desired signal file or generating a sample signal within the app. 3. Once your signal is loaded, navigate to the plot where you want to insert the threshold line or highlight peaks. 4. To insert a threshold line: - Click on the "Analysis" tab in the Signal Analyzer App. - Select the "Threshold" option from the dropdown menu. - Specify the threshold value you want to set. - The threshold line will be displayed on the plot at the specified value.

Note1: To add a threshold line, you can use the addThreshold function. This function allows you to specify a threshold value and visualize it on the plot.

5. To highlight peaks: - Click on the "Analysis" tab in the Signal Analyzer App. - Select the "Find Peaks" option from the dropdown menu. - Adjust the peak detection parameters as needed (such as peak prominence, height, etc.). - The identified peaks will be highlighted on the plot.

Note2: Utilize Matlab's built-in functions like findpeaks to detect peaks in your signal.

By following these steps, you can easily insert threshold lines or highlight peaks within the Signal Analyzer App in MATLAB.

For example, if you have a time-series signal and want to identify peaks above a certain threshold for further analysis, this functionality can be incredibly useful. By setting a threshold line and highlighting peaks, you can visually inspect and analyze important features of your signal data with ease.

Additionally, incorporating these visual aids can enhance your data interpretation and facilitate more informed decision-making based on your signal analysis results.

I hope this explanation and step-by-step guide help you effectively utilize threshold lines and peak highlighting features within the Signal Analyzer App in MATLAB. If you have any further questions or need additional assistance, feel free to ask!

[Priesemut]

Thanks for your answer. I can't find an "Analysis" tab in the Signal Analyzer App and thus also not a drop-down menu with a "Threshold" or "Findpeaks" item.

Typing "addThreshold" into the MATLAB console (REPL) results in

>> addThreshold
Unrecognized function or variable 'addThreshold'.

[Umar]

Hi Priesemut,

I did some research and found the function “ threshold”. For more information on this function, probably it was a typo, please refer to

https://www.mathworks.com/help/econ/threshold.html

Regarding “findpeaks” function, please refer to

https://www.mathworks.com/help/signal/ref/findpeaks.html

To help you with signal analyzer tool used in matlab, I would recommend follow the instructions listed below and let me know if this helps resolve your problem. I created my own custom signal analyzer in matlab and thought you might have created one as well. So, that might cause confusion.

1. Open the Signal Analyzer App on your device. 2. Load the signal data that you want to analyze into the app. 3. Once the signal is loaded, look for an option that allows you to customize the display settings or add annotations. This may be located in a menu or toolbar within the app. 4. Find the option to insert a threshold line. This could be labeled as "Add Threshold Line" or something similar. 5. Click on the option to add a threshold line and specify the desired threshold value. This line will then appear on the signal plot at the specified level. 6. To insert peaks into the signal display, look for a feature that enables peak detection or identification. This may be found in a separate menu or tool within the app. 7. Activate the peak detection feature and adjust any settings related to peak identification sensitivity or display preferences. 8. Once peaks are identified, they should be displayed on the signal plot as markers or indicators.

By following these steps, you should be able to easily insert a threshold line or peaks into the Signal Analyzer App for more detailed analysis of your signal data. If you encounter any difficulties or need further assistance, refer to the app's user manual or help documentation for additional guidance.