MATLAB Answers

## How to plot index number of a data in the graph?

Asked by Luan Gloria

### Luan Gloria (view profile)

on 14 Feb 2019
Latest activity Commented on by Luan Gloria

### Luan Gloria (view profile)

on 26 Mar 2019
Accepted Answer by Mark Sherstan

### Mark Sherstan (view profile)

Dear MatLab community members,
Let's say I have two vectors, A and B, with ten entries each. B = A*2; Let's say that A=1:1:10;
I want to plot A and B, but instead of ploting circles, crosses etc, I want to plot the index numbers of A and B to show that the content in the position 1 of A is doubled in B. In the picture below I show what I want: The red dots are the two first entries of vector A, and the blue dots are the two first entries of vector B, however, I cannot correlate these dots among each other (let's say I have a more complicated relationship between A and B, this relation would not be that easily seen). What I want to obtain, is a graph with the vector indexes as in the right side of the graph. Thank you!

madhan ravi

### madhan ravi (view profile)

on 14 Feb 2019
N=2;
text(1:N,A(1:N),"A index no"+(1:N))% like this?
text(1:N,B(1:N),"B index no"+(1:N))
Luan Gloria

### Luan Gloria (view profile)

on 14 Feb 2019
Dear Ravi, thank you for your reply.
No, I do not want to add a description to a ploted marker. Instead of a marker, I wanna plot a number, which is equivalent to the index of my data point. So, in the pictures below, instead of ploting the circles (or markers as 'o', 'x', '*', etc), I want my markers to be the data point equivalent indexes.  Sign in to comment.

## 1 Answer

Answer by Mark Sherstan

### Mark Sherstan (view profile)

on 14 Feb 2019
Accepted Answer

The following should get you going in the right direction. If you need more help please post your actual data set.
x = [1 2 3]
y = [4 5 6]
plot(x,y,'.','MarkerEdgeColor','w')
xlim([0 5])
ylim([0 10])
for ii = 1:length(x)
t = text(x(ii),y(ii),num2str(ii));
t.Color = [1 0 0];
end

Luan Gloria

### Luan Gloria (view profile)

on 26 Mar 2019
Thank you Mark! That's exactly what I was looking for.

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