%% prog20230616Distorsion

clearvars;
clear all;
close all;
clc;

%% lectura de audio y variables principales

%audio y frecuencia de muestreo
[x,fs] = audioread('violin.wav');

N = length(x);      %longitud del arreglo
dt = 1/fs;          %intervalo de muestreo
t = (0:N-1)*dt;     %tiempo

%grafico

figure(1)
plot(t,x,'b');
title('violin');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('x(t)');
axis([min(t),max(t),-1.25*max(abs(x)),1.25*max(abs(x))]);
grid on;
box on;

%sonido
sound(x,fs);

%% distorsion arcotangente
g1 = input('ganancia g1 = ');
y1 = (2/pi)*atan(g1*x);

figure(2)
plot(t,y1,'r');
title('violin distorsion1');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('y_1(t)');
axis([min(t),max(t),-1.25*max(abs(y1)),1.25*max(abs(y1))]);
grid on;
box on;

%sonido
sound(y1,fs);

figure(3)
plot(t,y1,'r',t,x,'b');
title('violin distorsion1');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('y_1(t)','x(t)');
axis([min(t),max(t),-1.25*max(abs(y1)),1.25*max(abs(y1))]);
grid on;
box on;


figure(4)
plot(x,y1,'r');
title('funcion de transferencia no lineal');
xlabel('x(t) (Pa)');
ylabel('y_1(t) (Pa)');
legend('H_{G1}');
axis([-1.25*max(abs(x)),1.25*max(abs(x)),-1.25*max(abs(y1)),1.25*max(abs(y1))]);
grid on;
box on;

%% uso de subplot
%subplot sirve para presentar varios graficos dentro de una misma ventana
%su uso es el siguiente

%figure(k)      "k" es un numero natural

%subplot(n,m,j)   "m","n" y "j" son numeros naturales donde m es fila   (horizontal)
%                                                           n es columna(vertical)
%                                                           j es numero de grafico
%                                                           j = 1,2,3,...m*n
%despues del comando subplot vienen los comando plot, semilogy,etc

figure(5)

subplot(2,2,1)
plot(t,x,'b');
title('violin');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('x(t)');
axis([min(t),max(t),-1.25*max(abs(x)),1.25*max(abs(x))]);
grid on;
box on;

subplot(2,2,2)
plot(t,y1,'r');
title('violin distorsion1');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('y_1(t)');
axis([min(t),max(t),-1.25*max(abs(y1)),1.25*max(abs(y1))]);
grid on;
box on;

subplot(2,2,3)
plot(t,y1,'r',t,x,'b');
title('violin distorsion1');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('y_1(t)','x(t)');
axis([min(t),max(t),-1.25*max(abs(y1)),1.25*max(abs(y1))]);
grid on;
box on;

subplot(2,2,4)
plot(x,y1,'r');
title('funcion de transferencia no lineal');
xlabel('x(t) (Pa)');
ylabel('y_1(t) (Pa)');
legend('H_{G1}');
axis([-1.25*max(abs(x)),1.25*max(abs(x)),-1.25*max(abs(y1)),1.25*max(abs(y1))]);
grid on;
box on;

%% distorsion sigmoide
g2 = input('ganancia g2 = ');
y2 = 1./(1 + exp(-g2*x))  - 0.5 ;

%normalizacion entre -1 y 1
y2 = y2/max(abs(y2));

sound(y2,fs);

figure(6)
plot(t,y2,'r');
title('violin distorsion2');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('y_2(t)');
axis([min(t),max(t),-1.25*max(abs(y2)),1.25*max(abs(y2))]);
grid on;
box on;

figure(7)

subplot(1,2,1)
plot(t,x,'b');
title('violin');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('x(t)');
axis([min(t),max(t),-1.25*max(abs(x)),1.25*max(abs(x))]);
grid on;
box on;

subplot(1,2,2)
plot(t,y2,'r');
title('violin distorsion2');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('y_2(t)');
axis([min(t),max(t),-1.25*max(abs(y2)),1.25*max(abs(y2))]);
grid on;
box on;

figure(8)

subplot(2,1,1)
plot(t,x,'k');
title('violin');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('x(t)');
axis([min(t),max(t),-1.25*max(abs(x)),1.25*max(abs(x))]);
grid on;
box on;

subplot(2,1,2)
plot(t,y2,'g');
title('violin distorsion2');
xlabel('tiempo t (s)');
ylabel('presion sonora p(t) (Pa)');
legend('y_2(t)');
axis([min(t),max(t),-1.25*max(abs(y2)),1.25*max(abs(y2))]);
grid on;
box on;