As per my understanding you want to plot the points(roots) using different colors according to sign of both the roots. One of the ways do to this is use “scatter” and pass a vector indicating different colors as an input argument to it. Here is the sample code by assuming data x,y:
x = 1:10;
y = 2:2:20;
cmap = jet(length(x)); % generates 10 colors (RGB values)
scatter(x, y, 10, cmap);
You can define a color vector accordingly and use “scatter” to achieve desired plot.
Refer the following link for more details on ”scatter”:
