CODEWITHSUNDEEP
matlabmatlab-figure
Gze
Gze

Reputation: 408

Color some samples of MATLAB figure with different color

I have a discrete signal x of length N traced in MATLAB using the command

stem(abs(x)); axis([0 N+6 0 4]);

The resulted figure is shown below:

enter image description here

My question I need only some values corresponding for example to index [7 10 11 12 15 18 48 50 52 60] to be colored with different color , let's say with red. How can I do that into my figure ?

Upvotes: 0

Views: 152

Answers (2)

Kenneth Boyd
Kenneth Boyd

Reputation: 667

This code makes just the circles red and not the stems

plot with selected red circles

%Vector relating to the sample/data point number
Sample = linspace(1,70,70);

%Random test data
X = randi([0,2],1,70);
stem(Sample,X);

%Key indices to change color
Key_Indices = [7 10 11 12 15 18 48 50 52 60];

line(Sample(Key_Indices), X(Key_Indices), 'linestyle', 'none', 'marker', 'o', 'color', 'r')

axis([0 70 0 3])
grid on

Upvotes: 0

MichaelTr7
MichaelTr7

Reputation: 4767

Using Multiple Plots by hold on and Matrix Indexing

You could possibly and alternatively place a plot on top of plot by using hold on. This does require an adjustment where you need a vector in this case Sample and Indices which specify the sample number/data point index. You can also use matrix indexing to get the amplitude/data points corresponding to the key point, Indicies.

Using Two Plots

%Vector relating to the sample/data point number%
Sample = linspace(1,70,70);

%Random test data%
X = randi([0,2],1,70);
stem(Sample,X);

hold on
%Key indices to change colour%
Key_Indices = [7 10 11 12 15 18 48 50 52 60];

%Matrix indexing to get values/amplitudes corresponding to key indices%
X_Prime = X(Key_Indices);

stem(Key_Indices,X_Prime,'r');

axis([0 70 0 3]);
hold off

Ran using MATLAB R2019b

Upvotes: 1

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