How to show dot graph in specific range

How can I show the dot that occour above 1

Answer 1

[Star Strider]

I am not certain what you want.

Adapt this to your data:

x = linspace(0, 7200, 250);                                 % Create ‘x’
y = rand(size(x))*4.5E+4;                                   % Create ‘y’

figure
plot(x, y, 'r.')
hold on
Lv = y>1E+4;                                                % Set Threshold At 1E+4
plot(x(Lv), y(Lv), '.b')
hold off
legend('All Data', 'Data Above Threshold')

.

[Phudit Kanittasut]

I want to show the dot that occour above 1

[Star Strider]

Change the threshold to 1:

Lv = y>1;                                                   % Set Threshold At 1E+4

then plot it as:

plot(x(Lv), y(Lv), '.r')

Choose whatever colour you want the dots to be.

[Phudit Kanittasut]

Is there any error in my code ?

[Star Strider]

I do not have your data, and I cannot run images of code in my version of MATLAB.

So, I have no idea if there are any errors in it, other than that the data you are loading is ‘pure_liver’. and you are plotting ‘pure_brain’ that apparently does not exist in your workspace. That would appear to me to be an error.

[Phudit Kanittasut]

Oh I already change it and nothing happen

[Star Strider]

I would need the data and your code (as text, not an image) to see what the problem is.

[Phudit Kanittasut]

pure_liver  = importdata('Pure Liver Spectra.csv');
[pks,locs] = findpeaks(pure_liver(:,2));  
x = 1:size(pure_liver,1);

%Pure brain peak
%figure
%plot(x, pure_brain(:,2))
%hold on
%plot(x(locs), pure_brain(locs,2), '^r')
%hold off
%grid


%Pure Brain Dot
figure
Lv = y>1;
plot(x(Lv), pure_liver(Lv), '.r')
grid
title('Pure Liver peak');



%save files
%dlmwrite('pks_data.csv',pks);

[Phudit Kanittasut]

This is my code and my data

[Star Strider]

All the ‘pks’ values are greater than 1, and range from 102 to 45448:

pure_liver = readmatrix('Pure Liver Spectra.csv');
[pks,locs] = findpeaks(pure_liver(:,2));  
x = 1:size(pure_liver,1);
[pks_min,pks_max] = bounds(pks)                                         % Minimum & Maximum Values Of ‘pks’

figure
Lv = pure_liver(locs,2)>1E+4;                                           % Set Threshold = 1E+4
% Lv = pure_liver(locs,2)>1;                                              % Set Threshold = 1
plot(x(locs(Lv)), pure_liver(locs(Lv),2), '.r')
grid
title('Pure Liver peak');

Note that what appears to be ‘1’ on the plot is actually . Choose the ‘Lv’ assignment that does what you want.