diff --git a/App/app.mlapp b/App/app.mlapp
index 85352a0..2aea4c0 100644
Binary files a/App/app.mlapp and b/App/app.mlapp differ
diff --git a/src/Generators/generate_pulse.m b/src/Generators/generate_pulse.m
new file mode 100644
index 0000000..2f9c316
--- /dev/null
+++ b/src/Generators/generate_pulse.m
@@ -0,0 +1,33 @@
+function x = generate_pulse(amplitude, frequency, phase, fs, duration, duty)
+% GENERATE_puse: returns a matrix of sampled pulse wave
+
+% CONTRIBUTORS:
+% Brian Tran: Created the wave
+
+% DOCUMENTATION:
+% phase shift is in number of periods
+% fs is the sampling frequency: how many sample points per second
+% duration is time in seconds
+% duty is a number between 0 and 1
+
+    % initialize local variables from input arguments
+    n = fs * duration; % number of samples (length of matrix)
+    dt = 1 / fs; % sampling period: time between two sample points
+    % initialize a one dimensional zero matrix to be populated
+    x = zeros(1, n);
+    f0=1e+6;  % 1MHz
+    Fs=3e+6;
+    Tf=0.001;  % 1 millisecond
+    t=0:1/Fs:Tf-1/Fs;
+    td=0.1;   % duty cycle 
+    A0=10; % 10 Volts
+    F=0;
+    N=1000; % Number of points 
+
+    % populate the matrix
+    for n = 1:N
+        F=F+(1/n)*cos(n*2*pi*f0*t).*sin(n*pi*td);
+    end
+    F=F*(2*A0/pi);
+    F=F+A0*td;
+end
\ No newline at end of file
diff --git a/src/NotWorking/fade_in.m b/src/Helper/fade_in.m
similarity index 70%
rename from src/NotWorking/fade_in.m
rename to src/Helper/fade_in.m
index 22bef76..bebb07f 100644
--- a/src/NotWorking/fade_in.m
+++ b/src/Helper/fade_in.m
@@ -12,16 +12,30 @@ function output = fade_in(input, time)
     
     len = length(input);
     
+    % need to use whole number for time
+    time = round(time);
+    
     % if time parameter longer than signal, treat time as
     % the duration of original signal
     if time > len
-        time = len
+        time = len;
+    end
+    
+    % in order to create array, time >=1
+    % if not, it's arbitrarily set to 1
+    % in which case the fade_in effect
+    % is virtually nonexistent
+    if time < 1
+        time = 1;
     end
 
     % set multiplier as 1D array
     % fade in effect: from no volume to full volume of signal
     multiplier = (1 : time) / time;
-
+    
+    while length(multiplier) < len
+        multiplier = [multiplier 1];
+    end
     % the resulting fade-in output  
     output = input .* multiplier;
 end
diff --git a/src/NotWorking/fade_out.m b/src/Helper/fade_out.m
similarity index 70%
rename from src/NotWorking/fade_out.m
rename to src/Helper/fade_out.m
index f50812b..954a1bb 100644
--- a/src/NotWorking/fade_out.m
+++ b/src/Helper/fade_out.m
@@ -11,18 +11,33 @@ function output = fade_out(input, time)
     
     len = length(input);
     
+    % need to use time as a whole number
+    time = round(time);
+    
     % if time parameter longer than signal, treat time as
     % the duration of original signal
     if time > len
         time = len
     end
 
+    % in order to create array, time >=1
+    % if not, it's arbitrarily set to 1
+    % in which case the fade_in effect
+    % is virtually nonexistent
+    if time < 1
+        time = 1;
+    end
+    
     % set multiplier as 1D array
 
     multiplier = (1 : time) / time;
 
     % fade out effect: from full volume of signal to no volume
-    multiplier = flip(multiplier)
+    multiplier = flip(multiplier);
+    
+    while length(multiplier) < len
+        multiplier = [multiplier 0];
+    end 
 
     % the resulting fade-in output  
     output = input .* multiplier;
diff --git a/src/NotWorking/distortion_filter.m b/src/NotWorking/distortion_filter.m
new file mode 100644
index 0000000..e60f7cd
--- /dev/null
+++ b/src/NotWorking/distortion_filter.m
@@ -0,0 +1,26 @@
+% An audio is distorted based on the value of HIGH. Nothing of a certain
+% threshold should be played above this constant, or they are simply clipped to this 
+% value. Inspired from Meghaj_Echo.m and epic_effect_schluep.m.
+% Author: Jason Liang
+
+function y = distortion_filter(x, HIGH)
+  len = length(X);
+  X = fft(x);
+  X = fftshift(X);
+  Y = zeros(1, len);
+  
+  for ind = 1:len
+    if (X(ind) > HIGH) 
+       Y(ind) = HIGH;
+    elseif (X(ind) < -HIGH)
+      Y(ind) = -HIGH;
+    else 
+      Y(ind) = X(ind);
+    end
+  end
+  
+  Y = fftshift(Y);
+  y = ifft(Y);
+  y = real(y);
+
+end
diff --git a/src/generate_heartbeat.m b/src/NotWorking/generate_heartbeat.m
similarity index 100%
rename from src/generate_heartbeat.m
rename to src/NotWorking/generate_heartbeat.m
diff --git a/src/Select/SoundGeneratorSelect.m b/src/Select/SoundGeneratorSelect.m
index 3fe715a..f99f4f2 100644
--- a/src/Select/SoundGeneratorSelect.m
+++ b/src/Select/SoundGeneratorSelect.m
@@ -1,26 +1,26 @@
-%Written by Darell 
+%Written by Darell, edited by Arthur Lu
 
 % CONTRIBUTORS:
 % Person1: Darell
+% Person2: Arthur Lu
 
 % DOCUMENTATION:
 %Pass-through function used by app
 
 function output = SoundGeneratorSelect(amplitude, frequency, phase, fs, duration, duty,number)
-    if(number == "Option 1")
+    if(number == "Sine")
         output = generate_sine(amplitude, frequency, phase, fs, duration, duty);
-    elseif(number == "Option 2")
+    elseif(number == "Square")
         output = generate_square(amplitude, frequency, phase, fs, duration, duty);
-    elseif(number == "Option 3")
+    elseif(number == "Triangle")
         output = generate_triangle(amplitude, frequency, phase, fs, duration, duty);
-    elseif(number == "Option 4")
+    elseif(number == "Sawtooth")
         output = generate_sawtooth(amplitude, frequency, phase, fs, duration, duty);
-    elseif(number == "Option 5")
+    elseif(number == "WhiteNoise")
         output = generate_white(amplitude, fs, duration);
-    elseif(number == "Option 6")
+    elseif(number == "HalfCircle")
         output = generate_halfCircles(amplitude, frequency, phase, fs, duration, duty);
     else
-        output = 0;
+        output = zeros(1, fs * duration);
     end
-end 
-
+end
\ No newline at end of file
diff --git a/src/distortion_filter.m b/src/distortion_filter.m
new file mode 100644
index 0000000..869aab7
--- /dev/null
+++ b/src/distortion_filter.m
@@ -0,0 +1,30 @@
+% An audio is distorted based on the value of HIGH. Nothing of a certain
+% threshold should be played above this constant, or they are simply clipped to this 
+% value. Inspired from Meghaj_Echo.m and epic_effect_schluep.m.
+% Author: Jason Liang
+% Mekhi Ellington: Added some comments and editted formatting
+
+function y = distortion_filter(x, HIGH)
+  len = length(X);    %Storing length of X.
+  X = fft(x);         %X is the Fourier Transform of x.
+  X = fftshift(X);    %Shifts X.
+  Y = zeros(1, len);  %Matrix of length containing zeros.
+  
+  for ind = 1:len
+    if (X(ind) > HIGH) 
+       Y(ind) = HIGH;
+
+    elseif (X(ind) < -HIGH)
+      Y(ind) = -HIGH;
+
+    else 
+      Y(ind) = X(ind);
+
+    end
+  end
+  
+  Y = fftshift(Y); %Shifts Y.
+  y = ifft(Y); %Inverse Fourier Transform of Y.
+  y = real(y); %Stores only the real part of the complex y.
+
+end
\ No newline at end of file
diff --git a/src/generate_cosine.m b/src/generate_cosine.m
new file mode 100644
index 0000000..8a013ed
--- /dev/null
+++ b/src/generate_cosine.m
@@ -0,0 +1,25 @@
+function x = generate_cosine(amplitude, frequency, phase, fs, duration, duty)
+% GENERATE_WAVENAME: returns a matrix of sampled WAVENAME wave
+
+% CONTRIBUTORS:
+% Mekhi Ellington: Original Creator
+
+% DOCUMENTATION:
+% phase shift is in number of periods
+% fs is the sampling frequency: how many sample points per second
+% duration is time in seconds
+% duty is a number between 0 and 1
+
+    % initialize local variables from input arguments
+    n = fs * duration; % number of samples (length of matrix)
+    dt = 1 / fs; % sampling period: time between two sample points
+    
+    % initialize a one dimensional zero matrix to be populated
+    x = zeros(1, n);
+    
+    % populate the matrix
+    for i = 1:n
+        t = i * dt;
+        x(i) = amplitude * cos(2*pi*frequency*t-phase);
+    end
+end
\ No newline at end of file
diff --git a/src/generate_trapezoid.m b/src/generate_trapezoid.m
new file mode 100644
index 0000000..69ce591
--- /dev/null
+++ b/src/generate_trapezoid.m
@@ -0,0 +1,55 @@
+function x = generate_trapezoid(amplitude, frequency, phase, fs, duration, duty)
+% GENERATE_TRAPEZOID: returns a matrix of sampled square wave
+
+% CONTRIBUTORS:
+% Daniel Doan: Author
+
+% DOCUMENTATION:
+% phase shift is in number of periods
+% fs is the sampling frequency: how many sample points per second
+% duration is time in seconds
+% duty cycle should be a number between 0 and 1.
+    % duty of 0.5 would have 2 trapezoids in first half of each cycle
+    % example of wave with duty of 0.5, where the peaks are amplitude/2: 
+    % 
+    %   ____ 
+    %  /    \
+    % /      \        ________________
+    %         \      /
+    %          \____/
+    % 
+
+
+
+% initialize local variables from input arguments
+    n = fs * duration; % number of samples (length of matrix)
+    dt = 1 / fs; % sampling period: time between two sample points
+    
+    % initialize a one dimensional zero matrix to be populated
+    x = zeros(1, n);
+    
+    % populate the matrix
+    for i = 1:n
+        t = i * dt;
+        
+        % periodic ramp from 0 to 1
+        % progression through a cycle
+        st = mod(frequency * t - phase, 1);
+        slope = (amplitude/2) / (duty/8);
+        if(st < duty)
+            if(st < duty/8 || st > 7*duty/8)
+                x(i) = slope * st;
+            else
+                if(st < 5*duty/8)
+                    x(i) = amplitude/2 - slope * (st-(3*duty/8));
+                end
+                if(st < 3*duty/8)
+                    x(i) = amplitude/2;
+                end
+                if(st > 5*duty/8)
+                    x(i) = -amplitude/2;
+                end
+            end
+        end
+    end
+end
\ No newline at end of file