how to change the markers and line style, for 'findpeaks' ?

Hello, According to the next code, how can I change the ‘markers’ and line style using the ‘findpeaks’ function? Thank you.

[pks,locs,widths,proms] = findpeaks(pws(:,end),y,'MinPeakHeight',trd); 
findpeaks(pws(:,end),y,'Annotate','extents','WidthReference','halfprom'); 
text(locs+0.5,pks,num2str((1:numel(pks))'));
legend('Filtered Data','Peak','Prominence','Width','FontSize',5);

Answer 1

[Walter Roberson]

ax = gca;
sig_h = findobj(ax, 'tag', 'Signal');
peak_h = findobj(ax, 'tag', 'Peak');

As you are asking to plot Extents as well, you will also have entries with tag 'Height', 'HalfHeightWidth', 'Border' (multiple); or 'Prominence', 'HalfProminenceWidth', 'Border' (multiple)

You can then set the LineStyle and Marker properties according to your preferences.

[Fercho_Sala]

@Walter Roberson Apparently it doesn’t work if you’re using a loop, here is the complete code. Thanks.

for cv6=1:N
     
    ax6=subplot(4, 6, cv6, 'Parent', tab6);
    sgtitle('Layering 30 minutes (2)');
    [pks2{cv6},locs2{cv6},widths2{cv6},proms2{cv6}]= findpeaks((smt2{1,cv6}(:,end)),y,'MinPeakHeight',trd); 
    findpeaks((smt2{1,cv6}(:,end)),y,'Annotate','extents','WidthReference','halfprom');
    text((locs2{cv6})+0.2,(pks2{cv6}),num2str((1:numel(pks2{cv6}))'));
    legend('Filtered Data','Peak','Prominence','Width','FontSize',2);
    
    ax6.YAxisLocation = 'right';
    ax6.XDir = 'reverse';
    ax6.XGrid = 'on';
    ax6.YGrid = 'off';
    name = sprintf('Layering (second) 30 minutes (%d)', cv6); 
    ylabel(name,'FontSize',5,'FontName','Arial','color','default');
    xlabel('Altitude/km','FontSize',5,'color','default');
    yticklabels('');
    xlim(ax6,[75 95]);
    ylim(ax6,[-inf inf]);
    camroll(-90);
end

[Walter Roberson]

for cv6=1:N
    ax6=subplot(4, 6, cv6, 'Parent', tab6);
    sgtitle(tab6, 'Layering 30 minutes (2)');
    [pks2{cv6},locs2{cv6},widths2{cv6},proms2{cv6}]= findpeaks((smt2{1,cv6}(:,end)),y,'MinPeakHeight',trd); 
    findpeaks((smt2{1,cv6}(:,end)),y,'Annotate','extents','WidthReference','halfprom');
    text(ax6, (locs2{cv6})+0.2,(pks2{cv6}),num2str((1:numel(pks2{cv6}))'));
    
    sig_h = find(ax6, 'tag', 'Signal');
    peak_h = find(ax6, 'tag', 'Peak');
    prom_h = find(ax6, 'tag', 'Prominence');
    hp_h = find(ax6, 'tag', 'HalfProminenceWidth');
    line_h = [sig_h, peak_h, prom_h, hp_h];
    set(line_h, 'LineStyle', '--', 'Marker', '+');
    
    legend(line_h, 'Filtered Data','Peak','Prominence','Width','FontSize',2);
    
    ax6.YAxisLocation = 'right';
    ax6.XDir = 'reverse';
    ax6.XGrid = 'on';
    ax6.YGrid = 'off';
    name = sprintf('Layering (second) 30 minutes (%d)', cv6); 
    ylabel(name,'FontSize',5,'FontName','Arial','color','default');
    xlabel('Altitude/km','FontSize',5,'color','default');
    yticklabels('');
    xlim(ax6,[75 95]);
    ylim(ax6,[-inf inf]);
    camroll(-90);
end

[Fercho_Sala]

ok, I got the next message:

Error using find

Undefined function 'find' for input arguments of type 'matlab.graphics.axis.Axes'.

@Walter Roberson

[Walter Roberson]

for cv6=1:N
    ax6=subplot(4, 6, cv6, 'Parent', tab6);
    sgtitle(tab6, 'Layering 30 minutes (2)');
    [pks2{cv6},locs2{cv6},widths2{cv6},proms2{cv6}]= findpeaks((smt2{1,cv6}(:,end)),y,'MinPeakHeight',trd); 
    findpeaks((smt2{1,cv6}(:,end)),y,'Annotate','extents','WidthReference','halfprom');
    text(ax6, (locs2{cv6})+0.2,(pks2{cv6}),num2str((1:numel(pks2{cv6}))'));
    
    sig_h = findobj(ax6, 'tag', 'Signal');
    peak_h = findobj(ax6, 'tag', 'Peak');
    prom_h = findobj(ax6, 'tag', 'Prominence');
    hp_h = findobj(ax6, 'tag', 'HalfProminenceWidth');
    line_h = [sig_h, peak_h, prom_h, hp_h];
    set(line_h, 'LineStyle', '--', 'Marker', '+');
    
    legend(line_h, 'Filtered Data','Peak','Prominence','Width','FontSize',2);
    
    ax6.YAxisLocation = 'right';
    ax6.XDir = 'reverse';
    ax6.XGrid = 'on';
    ax6.YGrid = 'off';
    name = sprintf('Layering (second) 30 minutes (%d)', cv6); 
    ylabel(name,'FontSize',5,'FontName','Arial','color','default');
    xlabel('Altitude/km','FontSize',5,'color','default');
    yticklabels('');
    xlim(ax6,[75 95]);
    ylim(ax6,[-inf inf]);
    camroll(-90);
end

[Fercho_Sala]

@Walter Roberson yes, that's the answer,, it worked so good, thanks a lot !!

[AStro]

@Walter Roberson I have tried to use the solution you proposed:

ax = gca;
sig_h = find(ax, 'tag', 'Signal');
peak_h = find(ax, 'tag', 'Peak');

Using it I am only able to change the style of peaks but I can not change the colour of the lines for prominence and halfprom

[Walter Roberson]

x = 1 : 50;
y = sin(x*2*pi/22);
findpeaks(y,x,'Annotate','extents','WidthReference','halfprom');
ax = gca;
sig_h = findobj(ax, 'tag', 'Signal');
peak_h = findobj(ax, 'tag', 'Peak');
prom_h = findobj(ax, 'tag', 'Prominence');
half_prom_h = findobj(ax, 'tag', 'HalfProminenceWidth');

prom_h.Color = [1 .3 1];
half_prom_h.Color = [.3 .8 .2];

[AStro]

For some reason the Prominence and HalfProminenceWidth tag is not recognized in my code

[pks_wc,locs_wc,widths,proms] = findpeaks(ampl_bgcorr,freq,'MinPeakDistance',p,'MinPeakProminence',10,'Annotate','extents','WidthReference','halfheight');
figure(1)
findpeaks(ampl_bgcorr,freq,'MinPeakDistance',p,'MinPeakProminence',10,'Annotate','extents','WidthReference','halfheight')
ax = gca;
sig_h = findobj(ax, 'tag', 'Signal');
peak_h = findobj(ax, 'tag', 'Peak');
proms_h = findobj(ax, 'tag', 'Prominence');
halfProm_h = findobj(ax, 'tag', 'HalfProminenceWidth');
peak_h.Marker = '.';
peak_h.MarkerSize = 10;
peak_h.Color = 'r';
sig_h.Color = 'b';
proms_h.Color = 'r';
halfProm_h.Color = 'r';

Change of the style of sig_h and peak_h are executed properly but for proms_h I get error message:

Property assignment is not allowed when the object is empty.  Use subscripted assignment to create an array element.
Error in CWT_software_v4 (line 142)
proms_h.Color = 'r';

[Walter Roberson]

I think I will need your data to test with

Answer 2

[Image Analyst]

I always plot the results myself:

[peakValues, indexesOfPeaks] = findpeaks(................)
plot(x, y, 'b-', 'LineWidth', 2); % Plot original data.
hold on;
% Extract peak locations from x and y.
xp = x(indexesOfPeaks);
yp = y(indexesOfPeaks);
plot(xp, yp, 'rv', 'LineWidth', 2, 'MarkerSize', 10); % Plot triangles atop the peaks.

Or you could skip creating xp and yp and have for the last line

plot(x(indexesOfPeaks), peakValues, 'rv', 'LineWidth', 2, 'MarkerSize', 10); % Plot triangles atop the peaks.