Question

I have a signal that is created from 0 to 1 for the square,rectangle and the sawtooth signals on the y axis how can I shift the signal down (vertical offset) so the signal will go from -0.5 to 0.5 on the y axis, and change the triangle signal from 0.5 to 1.0 to -0.5 to 0.5?

clear all
% SCRIPT BEGINS
t=linspace(0,1,22050)
freq=5%how many times it repeats in 1 sec
A = 1; % amplitude
T = 1/freq; % period of the signal

% square
square = mod(t * A / T, A) > A / 2;
plot(t, square)
title('Square');

% rectangle
l = 0.2; % percentage the signal spends on low value
rectangle = mod(t * A / T, A) > A * l;
figure;
plot(t, rectangle);
title('Rectangle');

% sawtooth
sawtooth = mod(t * A / T, A);
figure;
plot(t, sawtooth);
title('Sawtooth');

% triangle
triangle = (mod(t * A / T, A) > 0.5).*mod(t * A / T, A) + (mod(t * A / T, A) <= 0.5).*(1 - mod(t * A / T, A));
figure;
plot(t, triangle);
title('triangle');

thanks I’m using octave/matlab

Answer 1

function x_new = rescale(x, new_min, new_max)

x_min = min(x);
x_max = max(x);

x_new = new_min + (new_max - new_min) * (x - x_min) / (x_max - x_min);

(BTW this is very basic math that could have been easily googled)