Matlab Plots Very Small dots

Hi

I am facing this problem and it is getting quite annoying at the moment. Basically my matlab plots dots that are very small, it is so small that makes it hard to even see them. I used markersize property with value 10,20,10000.... and doesn't make any difference. Anyone knows what could have gone wrong ?

plot(data(i,1),data(i,2),'blue','markersize',200);

See if you can even spot it in this image :D

[Walter Roberson]

I see you edited the question, but the current version of the question is the same as what I remember the original being.

Your edit was after my Answer. Did you try the steps in my Answer?

Answer 1

[Jan]

The MarkerSize matters only, when a marker is used:

plot(1, 1, 'Marker', 'o', 'MarkerSize', 4, ...
     'MarkerFaceColor', 'b', 'MarkerEdgeColor', 'b');

The size of a single dot does not depend on the LineWidth:

axes('NextPlot', 'add', 'YLim', [0, 3]);
plot(1, 1, 'LineWidth', 4);
plot([0.5, 1.5], [2, 2], 'LineWidth', 4)

Answer 2

[Walter Roberson]

Try

set(gcf, 'Renderer', 'painters')

and also

set(gcf, 'Renderer', 'opengl')

if opengl is the one that fails, then try

opengl software

and see if it works then

[Pourya saber]

By Try do you mean to put them in my script or just run them in command window? I have tried both but didn't make any difference! Are there other things I could try ?

Also I Edited my topic because I realized it didn't make sense.

[Walter Roberson]

Ah. Your problem is that you are not specifying any marker, and the default is to use no markers.

[HYEWON HWANG]

Thank you so much

Answer 3

[Image Analyst]

I don't know why you're just plotting one data point, and you're not using the format description like I would. Try taking it out of your loop over i and plotting it after the loop like this:

plot(data(:,1), data(:,2), 'bo-','MarkerSize', 15);

For me, this certainly does let you change the marker size. You can leave it in the loop if you use hold on:

for k = 1 : size(data, 1)
  plot(data(k,1), data(k,2), 'bo-','MarkerSize', 15);
  if k == 1
    hold on;
  end
end

though this is less efficient/slower.

[Pourya saber]

I am actually plotting a whole dataset like this

for i = 1 : 20
    if i < 11
        rnd = mvnrnd(Mu1,Sigma1);
        data(i,1) = rnd(1,1);
        data(i,2) = rnd(1,2);
        data(i,3) = 1;
        plot(data(i,1),data(i,2),'red','markersize',20);
        hold on;
    else
        rnd = mvnrnd(Mu2,Sigma2);
        data(i,1) = rnd(1,1);
        data(i,2) = rnd(1,2);
        data(i,3) = -1;
        plot(data(i,1),data(i,2),'blue','markersize',20);
        hold on;
    end
end

I want to be able to distinguish between two set of data through their colors.

Interestingly this

plot(data(:,1), data(:,2), 'bo-','MarkerSize', 15);

allow me to change the size of those circles which is good. How can I add color to this ?

[Image Analyst]

Add the input parameter pair

, 'Color', [r g b]

where r, g, and b are numbers in the range 0-1. Alternatively if you want standard colors (r, g, b, y, m, c, k) you can just put those in instead of b (blue) in the 'bo-' argument, or after the 'Color' argument. You can also choose different standard markers (e.g. d=diamond, s = square, etc.) instead of o (for circles).