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TMX Transmultiplexer (MATLAB Version)

David Valencia ● February 2, 2011●6 comments ● Coded in Matlab 
% UPIITA IPN 2010
% Procesamiento Digital de Señales
% Grupo 6TM1  Equipo #8
% Team members
%   Rogelio Baeza Nieves
%   Ponce Mosso Catarina
%   Valencia Pesqueira José David

% TMX Transmultiplexer -> Chain processing

close all;clear all;clc;

n_stages = 2;
n_branches = 2^n_stages;
dec_factor = 2^n_stages;
niter = 500;

N = 16;
input = zeros(2^n_stages,N);
for(k = 0:2^n_stages-1)
    input(k+1,:) = (1 + k * N ):((k+1)*N);
end
input;
in_cnt = 1;

typeofbasis = 'o';
typbior = 'bior2.2';
typor = 'db2';

if(typeofbasis == 'b')
    [Rf,Df] = biorwavf(typbior);
    [h0,h1,g0,g1] = biorfilt(Df,Rf);
elseif (typeofbasis == 'o')
    [h0,h1,g0,g1] = wfilters(typor);
end;

L = length(h0);

try
    sinc_factor = getsinc(n_stages,L) - 1;
catch
    disp('Error');
    return
end

for i = 1:1
hx = fliplr(formafiltrosdwpt(n_stages,2^n_stages,h0,h1));
Lhx = length(hx);
H = zeros(2^n_stages, Lhx);
for i=0:(2^n_stages)-1
    H(i+1,:)=fliplr(formafiltrosdwpt(n_stages,2^n_stages-i,h0,h1));
end
La = length(H(1,:));

G = zeros(2^n_stages, Lhx);
for i=0:(2^n_stages)-1
    G(i+1,:)=fliplr(formafiltrosdwpt(n_stages,2^n_stages-i,g0,g1));
end
Ls = length(G(1,:));

double2cfloat(H,'h', G,'g',sinc_factor);

analysisbuffer = zeros(1,La);

y = zeros(2^n_stages,1);

sbuffer = zeros(2^n_stages, Ls);
xnbuff = zeros(2^n_stages,1);
chanbuffer = [0];
outputbuffer = zeros(2^n_stages,1);
end

for i=1:niter %General iteration counter
    
    %% Synthesis stage
    i
    % Vector shifting (CLK/1)
    for j = 1:(2^n_stages)
        sbuffer(j,:) = recorreder(sbuffer(j,:),1);
    end
    
% Input interpolation
    if (mod(i,2^n_stages) == 1)&&(in_cnt<N-1)
        sbuffer(:,1) = input(:,in_cnt);
        in_cnt = in_cnt + 1;
    else
        sbuffer(:,1) = zeros(2^n_stages,1);
    end
    
    disp('inputs: ');
    disp(sbuffer)
    
    xnbuff = zeros(2^n_stages,1);
    for j=0:(2^n_stages)-1
        for k = 1 : Ls %convolution
            xnbuff(j+1,1) = xnbuff(j+1,1) + sbuffer(j+1,k)*G(j+1,k);
        end
    end
    
    chanbuffer = sum(xnbuff)   
    
    %% Analysis stage
    analysisbuffer = recorreder(analysisbuffer,1);    
    analysisbuffer(1)=chanbuffer;
    analysisbuffer;
   
    if (i>sinc_factor && mod(i-sinc_factor,2^n_stages) == 1)
    % If the counter is a multiply of the decimating factor, then compute
        y = zeros(2^n_stages,1);
        for j = 0:(2^n_stages)-1
            for k=1:La %convolución
                y(j+1,1) = y(j+1,1) + analysisbuffer(k)*H(j+1,k);
            end;
        end
        outputbuffer = y;
    end
    input;
    i
    outputbuffer
    pause;
end
  	return;

TMX formafiltrosdwpt.m - Integrated version

David Valencia ● February 2, 2011 ● Coded in Matlab 
function [hx] = formafiltrosdwpt(n_stages,branch,h0,h1)
p = branch;

% Integrated version for DWPT/TMX filter generation

hx = 0;
hx(1) = 1;

switch n_stages
    case 1
        if mod(branch,2) ~= 0
            hx = h0;
        else
            hx = h1;
        end
    case 2
        switch branch
            case 1
                hx = conv(h0,upsample(h0,2));
            case 2
                hx = conv(h0,upsample(h1,2));
            case 3
                hx = conv(h1,upsample(h0,2));
            case 4
                hx = conv(h1,upsample(h1,2));
            otherwise
                beep;
                fprintf('\nERROR');
        end
        
    otherwise
        
        for i=0:n_stages-2
            q = floor(p /(2^(n_stages-1-i)));
            if (q == 1)
                hx = conv(hx,upsample(h1,2^i));
            else
                hx = conv(hx,upsample(h0,2^i));
            end
            p = mod(p,2^(n_stages-1-i)); %For DWPT and TMX
        end
        
        t = mod(branch,2);
        if(t == 1)
            hx = conv(hx,upsample(h0,2^(n_stages-1)));
        else
            hx = conv(hx,upsample(h1,2^(n_stages-1)));
        end
        
        
end

getsinc.m - TMX Transmultiplexer (MATLAB version)

David Valencia ● February 2, 2011 ● Coded in Matlab 
function [sf] = getsinc(n_etapas, L)

% Experimentally obtained synchronization factors

if(n_etapas == 1)
    sf = 2;

elseif (n_etapas == 2)
    sf = L;

elseif L == 4    
    if(n_etapas == 3) % 8 branches
        sf = 22;
    elseif(n_etapas == 4) % 16 branches
        sf = 36;
    elseif(n_etapas == 5) % 32 branches
        sf = 82;
    end
    
elseif L == 6
    if n_etapas == 3 % 8 branches
        sf = 20;
    elseif n_etapas == 4 % 16 branches
        sf = 30;
    elseif n_etapas == 5 % 32 branches
        sf = 80;
    end
    
elseif L == 8
    if(n_etapas == 3) % 8 branches
        sf = 26;
    elseif(n_etapas == 4) % 16 branches
        sf = 32;        
    end
    
elseif L == 10
    if(n_etapas == 1)
        sf = 2;
    elseif(n_etapas == 2)
        sf = 10;
    end
end

double2cfloat.m - TMX Filter formatting for C compilers

David Valencia ● February 2, 2011 ● Coded in Matlab 
% UPIITA IPN 2010
% José David Valencia Pesqueira

% This program is useful to convert numbers in MATLAB's Double
% format to a text file in float format for C compilers

% You should copy the resulting text to a file and save it with .h
% extension

% THIS PROGRAM RECEIVES AN UNIDIMENTIONAL VECTOR OF DOUBLE NUMBERS

% close all; clear all; clc;

function double2cfloat(x , namex, y, namey, sinc_factor)
[m,n] = size(x);
fprintf('// Begin of file\n\n');
fprintf('#define sinc %d // Sincronization factor\n',sinc_factor);
fprintf('#define N %d // Filter length\n',n);
if m~=0
    fprintf('#define M %d // Number of filters(branches)\n\n',m);
    fprintf('float %s[M][N]=',namex);    
else
    fprintf('float %s[N]=',namex);
end
disp('');
disp('{');
for i=0:m-1 %Rows
    if m~=1
        disp('{');
    end
    for j=0:n-1 %columns
        fprintf('%1.4e,\n',x(i+1,j+1));
    end
    if m~=1 
        fprintf('},\n');
    end
end
disp('};');
fprintf('\n\n');

if m~=0
    fprintf('float %s[M][N]=',namey);    
else
    fprintf('float %s[N]=',namey);
end
disp('');
disp('{');
for i=0:m-1 %Rows
    if m~=1
        disp('{');
    end
    for j=0:n-1 %columns
        fprintf('%1.4e,\n',y(i+1,j+1));
    end
    if m~=1 
        fprintf('},\n');
    end
end
disp('};');

fprintf('\n// EOF\n\n');

Circular Convolution Matrix

● February 1, 2011 ● Coded in Matlab 
function HC = convmtx_circ(h, N);
% CONVMTX_CIRC Circular Convolution Matrix.
%    CONVMTX_CIRC(h,N) returns the circular convolution matrix for vector h.
%    h must be a column vector. If X is a column vector of length N,
%    then CONVMTX_CIRC(h,N)*X is the same as the circular convolution h * X.
%
% by Danilo Zanatta - 01.02.2011

h = h(:);
Nh = length(h);
Nc = N + Nh - 1;

if N < Nh,
    error('The circular convolution matrix size must be greater or equal the channel length');
end

H = convmtx(h,N);

HC = H(1:N, 1:N);
HC(1:(Nh-1), 1:N) = HC(1:(Nh-1), 1:N) + H((N+1):Nc, 1:N);

return

This function helps in converting linear phase fir filter transfer function to min phase fir filter transfer function

● January 31, 2011●1 comment ● Coded in Matlab 
function [hn_min] = lp_fir_2_mp_fir(hn_lin)

% This function helps in converting the linear phase 
% FIR filter to minimum phase FIR filter. It essentially 
% brings all zeros which are outside the unit circle to 
% inside of unit circle.

r 	= roots(hn_lin);
k	= abs(r) > 1.01;
r1  	= r(k);		% roots outside of unit circle.
r2	= r(~k);% roots on or within the unit circle
s	= [1./r1; r2];
hn_min	= poly(s);
hn_min	= hn_min*sqrt(sum(hn_lin.^2))/sqrt(sum(hn_min.^2));

Fourier Trigonometric Series Approximation

David Valencia ● January 31, 2011 ● Coded in Matlab 
%Trigonometric Fourier Series Approximation
%José David Valencia Pesqueira - UPIITA-IPN
%As posted for Dsprelated.com
 
close all; clear all; clc;
syms t k;

fprintf('\n ### FOURIER TRIGONOMETRICAL SERIES###');

fprintf('\nSpecify the range (t1,t2) for the approximation:\n');
t1=input('t1= ');
t2=input('t2= ');

% Getting the period

fprintf('\nIs there a repeating patterin in this range? (Y/N): ');
resp1=input('','s');

switch resp1
    case 'Y'
        fprintf('\nWhat is the period for the function?\n');
        T=input('T= ');
        omega0=(2*pi)/T;
    case 'N'
        T=t2-t1;
        omega0=(2*pi)/T;
    otherwise
        fprintf('\nInvalid Option');
        fprintf('\nEnd of program>>>');
        return
end

fprintf('\nThe approximation will be generated in a trigonometrical series: \n\n');
fprintf('f(t)=a0+a1*cos(omega0*t)+a2*cos(2*omega0*t)+...+b1*sen(omega0*t)+b2*sen(2*omega0*t)');
 
fprintf('\n\nUntil what coefficient ak,bk should I compute? (positive integer) n= ');
n=input('');
if n<=0
    fprintf('Invalid n');
    fprintf('\nProgram Stop >>>');
    return
end

fprintf('\nIs the function defined by parts? (Y/N): ');
resp1=input('','s');

switch resp1
    case 'N'
        fprintf('\nWrite the function in terms of t\nf(t)= ');
        f=input('');
        
        faprox=0;

        a0=(1/T)*int(f,t,t1,(t1+T));
 
        faprox=a0;
 
        for k=1:n
            a(k)=(2/T)*int((f*cos(k*omega0*t)),t,t1,(t1+T));
            faprox=faprox+a(k)*cos(k*omega0*t);
        end
 
        for k=1:n
            b(k)=(2/T)*int((f*sin(k*omega0*t)),t,t1,(t1+T));
            faprox=faprox+b(k)*sin(k*omega0*t);
        end

    % If the function is defined in many parts
    case 'Y'
        fprintf('\nHow many ranges do you want to define (positive integer): ');
        numinterv=input('');
        numinterv=round(numinterv);
        for k=1:numinterv
            fprintf('\n## Range #%d definition',k);
            fprintf('\n Write the range in the form of t(%d)<t<t(%d) : ',k-1,k);
            fprintf('\nt(%d)= ',k-1);
            a(k,1)=input(''); %Initial limits vector
            fprintf('\nt(%d)= ',k);
            a(k,2)=input(''); %Final limit vector
            fprintf('\nThe range # %d has a start in %d and ends in %d',k,a(k),a(k+1));
            fprintf('\nPlease define f(t) for the %d th interval:\nf(t)= ',k);
            ft(k)=input('');
            fprintf('\nEnd of definition of the function f%d',k);
        end
        
        faprox=0;
        a0=0
        for j=1:numinterv
            a0=a0+(1/T)*int(ft(j),t,a(j,1),a(j,2));
        end
 
        faprox=a0;
 
        % ak coefficient
        ak=0;
        for j=1:numinterv
            acumulador=(2/T)*int((f(j)*cos(k*omega0*t)),t,a(j,1),a(j,2));
            ak=ak+acumulador;
        end

        return
        
        fprintf('\n## End of Debug Execution');
        return    
    otherwise
        fprintf('\nEND OF PROGRAM>>');
        return
end

%% Salida de datos
fprintf('\nThe resulting coeficcients are: ');
a0
a
b
 
fprintf('\n Do you wish to plot the graph of f(t) against the approximate series? (Y/N): ');
resp1=input('','s');
 
if resp1=='Y'
    ezplot(f,[t1,t2]);
    hold on
    ezplot(faprox,[t1,t2]);
    grid;
end
 
fprintf('\nEND OF PROGRAM');

Resampling based on FFT

Vashishth ● December 16, 2010●2 comments ● Coded in Matlab 
% FFTRESAMPLE Resample a real signal by the ratio p/q
function y = fftResample(x,p,q)

% --- take FFT of signal ---
f = fft(x);

% --- resize in the FFT domain ---
% add/remove the highest frequency components such that len(f) = len2
len1 = length(f);
len2 = round(len1*p/q);
lby2 = 1+len1/2;
if len2 < len1
  % remove some high frequency samples
  d = len1-len2;
  f = f(:);
  f(floor(lby2-(d-1)/2:lby2+(d-1)/2)) = [];
elseif len2 > len1
  % add some high frequency zero samples
  d = len2-len1;
  lby2 = floor(lby2);
  f = f(:);
  f = [f(1:lby2); zeros(d,1); f(lby2+1:end)];
end

% --- take the IFFT ---
% odd number of sample removal/addition may make the FFT of a real signal
% asymmetric and artificially introduce imaginary components - we take the
% real value of the IFFT to remove these, at the cost of not being able to
% reample complex signals
y = real(ifft(f));

2-D Ping Pong Game.

Vashishth ● December 16, 2010 ● Coded in Matlab 
%By vkc
function RunGame

    hMainWindow = figure(...
        'Color', [1 1 1],...
        'Name', 'Game Window',...
        'Units', 'pixels',...
        'Position',[100 100 800 500]);

    
    
    img = imread('ball.bmp','bmp');
    [m,n,c] = size(img);
    hBall = axes(...
        'parent', hMainWindow,...
        'color', [1 1 1],...
        'visible', 'off',...
        'units', 'pixels',...
        'position', [345, 280, n, m] );
    hBallImage = imshow( img );
    set(hBallImage, 'parent', hBall, 'visible', 'off' );
    ballSpeed = 3;
    ballDirection = 0;
    hTempBall = axes( ...
        'parent', hMainWindow,...
        'units', 'pixels',...
        'color', 'none',...
        'visible', 'off',...
        'position', get(hBall, 'position' ) );
    
    
    img = imread('paddle.bmp','bmp');
    [m,n,c] = size(img);
    
    hRightPaddle = axes(...
        'parent', hMainWindow,...
        'color', 'none',...
        'visible', 'off',...
        'units', 'pixels',...
        'position', [650 - 10, 250 - 50, n, m] );
    hRightPaddleImage = imshow( img );
    set(hRightPaddleImage, 'parent', hRightPaddle, 'visible', 'off' );
    targetY = 200;
    t = timer(  'TimerFcn', @UpdateRightPaddleAI,...
                'StartDelay', 10 );
            start(t)
    
    

    hLeftPaddle = axes(...
        'parent', hMainWindow,...
        'color', 'none',...
        'visible', 'off',...
        'units', 'pixels',...
        'position', [50, 250 - 50, n, m] );
    hLeftPaddleImage = imshow( img );
    set(hLeftPaddleImage, 'parent', hLeftPaddle, 'visible', 'off' );

    hBottomWall = axes(...
        'parent', hMainWindow,...
        'color', [1 1 1],...
        'units', 'pixels',...
        'visible', 'off',...
        'position', [0 40 700 10] );
    patch( [0 700 700 0], [0 0 10 10], 'b' );    
    
    hTopWall = axes(...
        'parent', hMainWindow,...
        'color', [1 1 1],...
        'units', 'pixels',...
        'visible', 'off',...
        'position', [0 450 700 10] );
    patch( [0 700 700 0], [0 0 10 10], 'b' );
    
    rightScore = 0;
    leftScore = 0;
    hRightScore = axes(...
        'parent', hMainWindow,...
        'color', 'none',...
        'visible', 'off',...
        'units', 'pixels',...
        'position', [650 485 50 10] );
    hLeftScore = axes(...
        'parent', hMainWindow,...
        'color', 'none',...
        'visible', 'off',...
        'units', 'pixels',...
        'position', [30 485 50 10] );
    hRightScoreText = text( 0, 0, '0', 'parent', hRightScore,...
        'visible', 'on', 'color', [1 1 1] );
    hLeftScoreText = text( 0, 0, '0', 'parent', hLeftScore,...
        'visible', 'on', 'color', [1 1 1] );
    
    
    
    hQuitButton = uicontrol(...
        'string', 'Quit',...
        'position', [325 475 50 20],...
        'Callback', @QuitButton_CallBack );
    
    hStartButton = uicontrol(...
        'string', 'Start',...
        'position', [325 240 50 20],...
        'Callback',@StartButton_CallBack );

    playing = true; 
    

    while playing == true
        

        UpdateBall()
        UpdateLeftPaddle()
        UpdateRightPaddle()

        CheckForScore()

        pause( 0.01 )
    end
    stop(t)
    close( hMainWindow )
    
    
    
    
    
    
    
    

    
    
    function UpdateBall
        
       pos = get( hBall, 'position' );
       ballX = pos(1,1);
       ballY = pos(1,2);
       
       ballDirection = NormalizeAngle( ballDirection );
      
       
       % check for collisions with the walls
       if ( ballY > 450 - 10 ) && ( ballDirection > 0 ) && ( ballDirection < 180 )
            if ( ballDirection > 90 )
                ballDirection = ballDirection + 2 * ( 180 - ballDirection );
            else
                ballDirection = ballDirection - 2 * ballDirection;
            end
       elseif ( ballY < 50 ) && ( ballDirection > 180 ) && ( ballDirection < 360 )
            if ( ballDirection > 270 )
                ballDirection = ballDirection + 2 * ( 360 - ballDirection );
            else
                ballDirection = ballDirection - 2 * ( ballDirection - 180 );
            end
       end
       
       % check for collisions with the paddles
       
       if ( ballDirection > 90 && ballDirection < 270 )
           
            leftPaddlePos = get( hLeftPaddle, 'position' );
            leftX = leftPaddlePos(1,1);
            leftY = leftPaddlePos(1,2);
          
            if(     (ballX < leftX + 10)...
                &&  (ballX > leftX + 5)...
                &&  (ballY + 10 > leftY)...
                &&  (ballY < leftY + 100)     )
                
                if ( ballDirection < 180 )
                    ballDirection = 180 - ballDirection;
                elseif( ballDirection > 180 )
                    ballDirection = 180 - ballDirection;
                end
            end
       else
            rightPaddlePos = get( hRightPaddle, 'position' );
            rightX = rightPaddlePos(1,1);
            rightY = rightPaddlePos(1,2);
            
            if(     (ballX + 10 > rightX)...
                &&  (ballX + 10 < rightX + 5)...
                &&  (ballY > rightY)...
                &&  (ballY < rightY + 100)  )
                
                if ( ballDirection < 90 )
                    ballDirection = 180 - ballDirection;
                elseif( ballDirection > 270 )
                    ballDirection = 180 - ballDirection;
                end
            end
       end
           
       MoveObject( hBall, ballSpeed, ballDirection );
        
    end

    
    function UpdateRightPaddle()

         
         speed = 5;
         pos = get( hRightPaddle, 'position' );
         rightY = pos(1,2);
         
         
         
         if( rightY + 5 < targetY - 50 && rightY < 400 - 50 )
             MoveObject( hRightPaddle, speed, 90 )
         elseif( rightY - 5 > targetY - 50 && rightY > 50 )
             MoveObject( hRightPaddle, speed, 270 )
         end
      
         pos = get( hRightPaddle, 'position' );
         rightY = pos( 1,2);
         if( rightY > 400 - 50 )
             rightY = 350;
         elseif( rightY < 50 )
             rightY = 50;
         end
         
         
        if( strcmp( get( t, 'Running' ), 'off' ) )
            start(t)
        end
    
    end

    function UpdateRightPaddleAI( ob, data )
        
        % calculate where the ball will colide.
        tempBallDirection = NormalizeAngle( ballDirection ); 
        if( tempBallDirection < 90 || tempBallDirection > 270 && ballSpeed > 0 )
           
            ballPos = get( hBall, 'position' );
            set( hTempBall, 'position', ballPos );
            ballX = ballPos(1,1);            
            while( ballX < 650 - 10  )
                
                ballPos = get( hTempBall, 'position' );
                ballX = ballPos(1,1); 
                ballY = ballPos(1,2);
                MoveObject( hTempBall, 20, tempBallDirection )

               % check for temp ball collision with walls.
               if ( ballY > 450 - 10 ) 
                   if ( tempBallDirection > 0 ) 
                       if ( tempBallDirection < 180 )    
                            tempBallDirection = 360 - tempBallDirection;
                       end
                   end
               elseif ( ballY < 60 ) 
                   if( tempBallDirection > 180 ) 
                       if( tempBallDirection < 360 )
                            tempBallDirection = 360 - tempBallDirection;
                       end
                   end
               end

%                     line( 0, 0, 'marker', '*', 'parent', hTempBall )
%                     pause( 0.0005 )
            end

            pos = get( hTempBall, 'position' );
            ballY = pos(1,2);
            targetY = ballY + ( rand * 150 ) - 75;
            
        end
    end

    function UpdateLeftPaddle()    
        scr = get( hMainWindow, 'position' );
        screenX = scr(1,1);
        screenY = scr(1,2);
        screenH = scr(1,4);
        
        mouse = get(0, 'PointerLocation' );
        y = mouse(1,2) - screenY;
        
        if( y > 100 && y < 400 )
            paddlePos = get( hLeftPaddle, 'position' ); 
            paddlePos(1,2) = y - 50; 
            set( hLeftPaddle, 'position', paddlePos );
        elseif( y > 400 )
            paddlePos = get( hLeftPaddle, 'position' ); 
            paddlePos(1,2) = 400 - 50; 
            set( hLeftPaddle, 'position', paddlePos ); 
        elseif( y < 100 )
            paddlePos = get( hLeftPaddle, 'position' ); 
            paddlePos(1,2) = 100 - 50; 
            set( hLeftPaddle, 'position', paddlePos );
        end
        
    end

    function CheckForScore()
        
       pos = get( hBall, 'position' );
       xpos = pos(1,1);
       ypos = pos(1,2);
       
       if ( xpos < 5 )
           set( hBallImage, 'visible', 'off' )
           rightScore = rightScore + 1;
           set ( hRightScoreText, 'string', num2str( rightScore ) )
           pause( .5 )
           ResetBall()
       elseif ( xpos + 10 > 695 )
           set( hBallImage, 'visible', 'off' )
           leftScore = leftScore + 1;
           set ( hLeftScoreText, 'string', num2str( leftScore ) )
           pause( .5 )
           ResetBall()
       end
       
    end
        
    function ResetBall
        
        pos = get( hBall, 'position' );
        pos(1,1) = 345;
        pos(1,2) = 255 + floor( rand*100 ) - 50;
        set( hBall, 'position', pos )
        ballSpeed = 4;
        ballDirection =  ( (rand(1) < 0.5) * 180 ) ...          % 0 or 180
                       + ( 45 + (rand(1) < 0.5) * -90 ) ...     % + 45 or - 45
                       + ( floor( rand * 40 ) - 20 );           % + -20 to 20
        set( hBallImage, 'visible', 'on' )
        pause(1)
        
    end
    

    function MoveObject( hInstance, speed, direction )

        p = get( hInstance, 'position' );

        x = p( 1, 1 );
        y = p( 1, 2 );
        
        x = x + cosd( direction ) * speed;
        y = y + sind( direction ) * speed;

        p( 1, 1 ) = x;
        p( 1, 2 ) = y;

        set( hInstance, 'position', p )

    end

    function SetObjectPosition( hObject, x, y )
       
       pos = get( hObject, 'position' );
       pos(1,1) = x;
       pos(1,2) = y;
       set( hObject, 'position', pos )
        
    end

    function a = NormalizeAngle( angle )
        
        while angle > 360
            angle = angle - 360;
        end
        
        while angle < 0
            angle = angle + 360;
        end
        a = angle;

    end

    function QuitButton_CallBack( hObject, eventData )
        playing = false;
    end

    function StartButton_CallBack( hObject, eventData )
        set( hObject, 'visible', 'off' );
        set( hLeftPaddleImage, 'visible', 'on' )
        set( hRightPaddleImage, 'visible', 'on' )
        ResetBall();
    end

end

Passive direction finding

● December 15, 2010 ● Coded in Matlab 
clc
clear all
close all

fs=20e7;
T=1/fs;

t=0:T:0.0000002;
f=10e6;
scanagle_deg=60;
step_deg=6;

theta=-deg2rad(scanagle_deg):deg2rad(step_deg):deg2rad(scanagle_deg);

for i=1:length(theta);

ant1=2*sin(2*pi*f*t);
ant2=2*sin(2*pi*f*t+theta(i));

[my,mx]=max(ant1);

sum_ant(i)=ant1(mx)+ant2(mx);
diff_ant(i)=ant1(mx)-ant2(mx);
ratio_ant(i)=diff_ant(i)/sum_ant(i);

% if diff_ant(i)==0
%     diff_ant(i)=0.1;
% end
% ratio1_ant(i)=sum_ant(i)/diff_ant(i);

end

% subplot(311)
% plot(t,ant1,t,ant2)
subplot(211)
plot(rad2deg(theta),sum_ant,rad2deg(theta),diff_ant)
subplot(212)
plot(rad2deg(theta),ratio_ant)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

sim_ant1=2*sin(2*pi*f*t);
sim_ant2=2*sin(2*pi*f*t+deg2rad(30));

[smy,smx]=max(sim_ant1);

%%%%also take for same sample value of data

sim_sum_ant=sim_ant1(mx)+sim_ant2(mx);
sim_diff_ant=sim_ant1(mx)-sim_ant2(mx);
sim_ratio_ant=sim_diff_ant/sim_sum_ant