make dot and count them

how to make dots (points) in an axes and count them.. may I use "ginput".. how i can make it..?? thank you.. ^^

[Jan]

The question is not clear yet. How do you define where the dots appear? If you draw the plots in a program, there is no reason to count them afterwards, because the number of dots is known already.

[Rahma Yeni]

i'm so sorry, if my question is not clear yet.. ^^

i want to make some dots in an axes..

because, sometimes i make much dots in an axes, so i must calculated how much dots that i has made.. value of the number of dots will be appear in a edit ...

[Rahma Yeni]

I would prefer to explain it in pictures

http://www.flickr.com/photos/rye_ni/7070715047/

thank you before.. ^^

[Jan]

How do you "make some dots in an axes"? Isn't it possible to count the dots during creation already?

Answer 1

[Thomas]

Is this what you want

E.G.

close all
  clear variables %changed from clear all on Jan's suggestion

   disp('Hit return (enter) to stop entering points');
    [x,y]=ginput;  % hit return(enter) to stop entering points
    plot(x,y,'MarkerFaceColor',[0 0 0],'MarkerEdgeColor',[0 0 0],'Marker','o','LineStyle','none');
  num_points=(length(x))

[Jan]

Is "close all; clear all" really helpful here?! Is it ever?!

[Thomas]

not really helpful, but try, running this code twice without the 'close all' , you'll come to know, why I put it in..

[Jan]

I'd rather create the AXES explicitely than letting GINPUT do this implicitely and force colosing of all open figures.

"clear all" removes all loaded functions from the memory. Reading and parsing them again wastes a lot of time. Perhaps you want "clear variables".

[Thomas]

I agree, that clear all removes all functions loaded from memory, but it is easier to type 'clear all' than 'clear variables' for small snipets of code :) .. As for the question of creating axes explicitly rather than have GINPUT create it, I would leave that up to the user.. I was just demonstrating a proof of concept based on an ambiguous question.

[Jan]

@Thomas, I would not have mentioned the problems of "clear all", if this appears less frequently in this forum. It does not cause any problems in your example. But I see it in so many examples, even as first line inside functions -where it is even weird-, that I suggest repeatedly to avoid it. A lot of FEX submissions contain "clear all, close all" and testing them can destroy my current work.

[Rahma Yeni]

Thank you all..

i can applied the code to my problem.. ^^