Plot label with text function

Hi everyone, please help debug the error in the code below

I made a plot in which I added a text to each peaks (peak assignment with label) but the alignment of the text are not well placed accordingly. See below my script and the plot generated with the script. I want the text label to be close to each of the peaks identified. I also attached the data I plotted. Thanks

NB: 'Si_layer1_ExpN' is my experimental data which represent intensity, 'wv1' is the wavelenght of my experimental data and 'matched data' (struct) is the result of the comparison I did with my experimental data using a database.

script

figure;
plot(wv1, Si_layer1_ExpN, 'b', 'LineWidth', 1);
hold on
for i = 1:length(matched_data)
    plot(matched_data(i).wavelength, matched_data(i).intensity, 'ko', 'MarkerSize', 5);
    text(matched_data(i).wavelength, matched_data(i).intensity, matched_data(i).labels, 'VerticalAlignment', 'bottom', 'HorizontalAlignment', 'left', 'Color', 'k');
end
xlabel('Wavelength (nm)');
ylabel('Intensity');
legend('Experimental Data', 'Matched Peaks');

The script return first plot below

I want the peak labelling to look like the below plot. Labels placed close to each peaks.

Answer 1

[Star Strider]

All the ‘matched_data.intensity’ entries are all set to 1, so they all plot at 1 rather than the peak values. A way to correct for that is to add this interp1 call to the loop before the others:

matched_data(i).intensity = interp1(wv1, Si_layer1_ExpN, matched_data(i).wavelength);

That interpolates the correct values, based on the ‘matched_data.wavelength’ values. No other changes to your code are necessary.

Try this —

load('matlab_data.mat')
% whos

figure;
plot(wv1, Si_layer1_ExpN, 'b', 'LineWidth', 1);
hold on
for i = 1:length(matched_data)
    matched_data(i).intensity = interp1(wv1, Si_layer1_ExpN, matched_data(i).wavelength);
    plot(matched_data(i).wavelength, matched_data(i).intensity, 'ko', 'MarkerSize', 5);
    text(matched_data(i).wavelength, matched_data(i).intensity, matched_data(i).labels, 'VerticalAlignment', 'bottom', 'HorizontalAlignment', 'left', 'Color', 'k');
end
xlabel('Wavelength (nm)');
ylabel('Intensity');
legend('Experimental Data', 'Matched Peaks');

.

[Doyinsola]

Thank you. This really solved my many trial and errors with ease. Thank you once again.

[Star Strider]

As always, my pleasure!

Answer 2

[the cyclist]

The intensities in your structure do not line up with the variable Si_layer1_ExpN.

I show this below by splitting figure into two subplots, and making your plot markers bigger:

load("matlab_data.mat")

figure
tiledlayout(2,1)

nexttile
plot(wv1, Si_layer1_ExpN, 'b', 'LineWidth', 1);

nexttile
hold on
for i = 1:length(matched_data)
    plot(matched_data(i).wavelength, matched_data(i).intensity, 'ko', 'MarkerSize', 8);
    text(matched_data(i).wavelength, matched_data(i).intensity, matched_data(i).labels, 'VerticalAlignment', 'bottom', 'HorizontalAlignment', 'left', 'Color', 'k');
end
xlabel('Wavelength (nm)');
ylabel('Intensity');

Notice that the two y-axes have very different ranges.

I'm not sure how you want to solve that, so I'll leave it at that.

[Doyinsola]

Thank you for your attempt and help. I have been able to solve the problem with the code shared by star strider.