how can i write the number of line?

Hi!

I have a 2D plot and I want to appear on each point of the graph, the number of lines corresponding to the matrix of data.

Is there any way?

Thank you!

[Matz Johansson Bergström]

Can you provide us with an example?

[Giorgos Papakonstantinou]

Hi Thodoris. Can you explain a bit more your question? I don't understand which lines you want to show in the 2D plot?

[Thar]

my data are in two columns:

 300 3.345
 301 4.456
 303 5.789

I have the plot from these data. I want to each point in the graph to write the number of line. for example, in the point (300, 3.345) to write 1.

Answer 1

[Geoff Hayes]

Thodoris - if you want to write the row (or line) that each point corresponds to, try using the text function. Something like

 figure;

 data = [300 3.345
         301 4.456
         303 5.789];

 xlim([min(data(:,1))-1,max(data(:,1))+1]);
 ylim([min(data(:,2))-1,max(data(:,2))+1]);

 sRows = num2str([1:size(data,1)]');
 text(data(:,1),data(:,2),sRows);

The xlim and ylim are just used for illustration purposes to ensure that we can see the area we are interested in (that given by data). We then create a vector of strings, one for each row number using

 sRows = num2str([1:size(data,1)]');

and then label each point in data with those strings using text.

Try the above and see what happens!

Answer 2

[Image Analyst]

Try this:

m=[...
  300 3.345
  301 4.456
  303 5.789]
for row = 1 : size(m, 1)
  x = m(row, 1);
  y = m(row, 2);
  plot(x, y, 'b*', 'MarkerSize', 15);
  hold on;
  caption = sprintf('(%.3f, %.3f)', x, y);
  text(x+0.8, y, caption, 'FontSize', 15);
end
grid on;
xlim([296, 315]);