How to plot it?

20 views (last 30 days)
Ara
Ara on 13 Jul 2022
Commented: Ara on 16 Jul 2022
Dear All,
We have
a=1,2,3,4,5; (in a column 1)
b=-1000,10,0,20,-20; (in a column 2)
b_filtered=b(:,2)>=0;
plot (a,b_filtered);
How to plot these two values that after filtered they have two different dimensions?
Best,

Accepted Answer

Chunru
Chunru on 13 Jul 2022
a = [1,2,3,4,5];
b = [-1000,10,0,20,-20];
idx = b>=0;
plot(a(idx), b(idx), 'o-');
  3 Comments
Chunru
Chunru on 16 Jul 2022
plot(a.a(idx,1), a.a(idx,2), 'o-');
Ara
Ara on 16 Jul 2022
Thank you.
your plot is different with the other answeres. I do not know which one is correct to adapt it to my code. Do you know?

Sign in to comment.

More Answers (3)

Mathieu NOE
Mathieu NOE on 13 Jul 2022
hello
simply replace the negative values of b by NaN so the vector size remains the same
a=[1;2;3;4;5];
b= [-10;10;0;20;-20];
b_filtered=b;
b_filtered(b<0) = NaN;
plot (a,b,a,b_filtered,'dr');
  3 Comments
Mathieu NOE
Mathieu NOE on 13 Jul 2022
hello
both answers are correct and will display the exact same plot
I wanted to have both b and b_filtered the same size as a , because it seemed to me that you wanted it this way.
the other options as suggested by @Chunru works also , and if you want to have both b and b_filtered displayed , you can slightly modify his code :
it's up to you to pick the one you prefer
a = [1,2,3,4,5];
b = [-10,10,0,20,-20];
idx = b>=0;
plot(a,b,a(idx), b(idx), 'or');
Ara
Ara on 16 Jul 2022
Hello Mathieu,
The plot you provided is different with the plot above provided by another expert who response to my question. I am confuse as I do not know which one is correct and how to modify my code based on which solution. Would you please tell me which one is correct?

Sign in to comment.


Ruchika P Barman
Ruchika P Barman on 13 Jul 2022
It is my understanding that you are trying to plot a and b_filtered. I believe b_filtered is supposed to contain the non-negative elements of b, please correct me if I'm wrong on this, I did not understand what exactly is (b(:,2)>=0) supposed to do? If I'm not wrong, we can retain the elements of a at the indices where b is not negative and plot a and b accordingly.
a=[1;2;3;4;5];
b= [-10;10;0;20;-20];
b(b<0)=NaN;
a(b<0)=NaN;
b_filtered=b;
p=plot (a,b_filtered,"red");

Ara
Ara on 13 Jul 2022
Thank you Ruchika, for your response.
it means second column of my data should be greater than zero. I do not know which answer is correct as the figure for second answer isnot the same with yours. You and the first answer are the same output.
I have to modify it in a large set of data.
  3 Comments
Ara
Ara on 14 Jul 2022
Hello,
I meant second column of b, which is a column with many data.
Ara
Ara on 15 Jul 2022
Edited: Ara on 15 Jul 2022
I have "data" file. When I open it in matlab that consist of 12 coumns and one of them is b. So, b is a column that contain a full range of data in a one column.

Sign in to comment.

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!