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