Group the values of a graph in four

I need to group in 4 the values of these two vectors of 1500 numbers ranging from -100 to 100, so that the following graph divided into 4 sections appears. I do not know whether to use axes or what procedure to execute

x=-100+(100+100)*rand(1500,1);   
y=-100+(100+100)*rand(1500,1);   
plot(x,y,'or')

[Walter Roberson]

What should be the criteria to divide them?

The graph already appears, so it is not clear what you are asking for?

[Dionisio Mendoza]

I want to divide that graph like this

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Walter Roberson]

group = (x <= 0) * 2 + (y <= 0) + 1;
pointsize = 15;
scatter(x, y, pointsize, group);
colormap(jet(4))

[Dionisio Mendoza]

Thanks,It's pretty similar to what I'm looking for, but how can I define the chords of each section and its character?

[Walter Roberson]

I do not know what you mean by a "chord" of a section, or "character" of a section.

[Dionisio Mendoza]

i mean colors of each section

[Walter Roberson]

You can create a 4 x 3 matrix of color values and colormap() that matrix.