limit the axes for plotting in Matlab [duplicate]

Answer 1

Yes you can specify the limits directly on the axes using set or by calling the xlim, ylim, and zlim functions

plot(rand(1,100));
set(gca,'XLim', [10 20] ); % set the xlims to 10,20

or

plot(rand(1,100));
xlim([10 20]); % set the xlims to 10,20

Answer 2

Well, this is probably too obvious to be the solution to your problem, but in this line:

scatter(x(1:end-1), y(1:end-1),5, lg);

If lg is the same size as x and y, then clearly this is wrong and you need to do:

scatter(x(1:end-1), y(1:end-1),5, lg(1:end-1));

If this does not solve your problem, then as I stated in my comment you must provide complete code that we can run to reproduce the problem, including sample data for the x, y, and lg vectors.