Highlight a part of a plot by drawing it in a different color

Question

Given a plot with e.g. a curve like shown on the following figure I want to highlight the curve in the interval 150 <= x <= 200. I would prefer simply drawing this int

Answer 1

A quick example:

%# plot data
x = linspace(0,2*pi,75);
y = sin(x);
plot(x, y, 'b.')

%# higlight points of interest
idx = (4 <= x & x <= 6);
hold on, plot(x(idx), y(idx), 'r.')
hold off

Answer 2

The proper way to do it would be to provide an n*3 matrix of color values, for n data points.

C = zeros(size(x,2), 3);
C(x>=150 & x<=200,1) = 1; % red
C(x<150 | x>200,3) = 1; % blue
scatter(x, y, 25, C, 'd', 'filled');