Plot shifting between two values in if statement

Question

Rock Rocky 2017-9-6

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/355401-plot-shifting-between-two-values-in-if-statement

回答： dpb 2017-9-6

Hello there I have if statement contain two equations as shown in the attached picture. This algorithm have two step size values represented by c and d respectively. The algorithm will shift between these two values according to the if statement. how can I plot the shifting between c and d. Thanks in advance.

if true
 echo on
r=0;
N=500;
K=5;
num=0;
sum=0;
actual_isi=[0.05 -0.063 0.088 -0.126 -0.25 0.9047 0.25 0.126 0.038 0.088];
sigma=0.01;
delta=0.09;
deviation=0.004;
Num_of_Realizations = 1000;
mse_av=zeros(1,N-2*K);
c=delta+deviation;
d=delta-deviation
for j=1:Num_of_Realizations,
  %information sequence
  for i=1:N,
      if (rand<0.5),
          info(i)=-1;
      else
          info(i)=1;
      end;
      echo off;
  end;
  if (j==1);echo on ; end
  %The Channel Output
  y=filter(actual_isi,1,info);
  for i=1:2:N, [noise(i) noise(i+1)]=gngauss(sigma); end;
  y=y+noise;
  %Now the Equalization part follows
  estimated_c=[0 0 0 0 0 1 0 0 0 0 0]; %Initial Estimate of ISI
  e_k1=0;
  cnt = 1;  % Loop counter.
  for k=1:N-2*K,
      y_k=y(k:k+2*K);
      z_k=estimated_c*y_k.';
      e_k=info(k)-z_k; 
      n=norm(y_k);
      if(e_k>e_k1)
          estimated_c=estimated_c+(c)*e_k*y_k/n;
        elseif(e_k<=e_k1)
            estimated_c=estimated_c+(d)*e_k*y_k/n;
        end
        e_k1=e_k;  
%         estimated_c=estimated_c+delta*e_k*y_k;
        mse(k)=e_k^2;
        echo off;
    end;
    if (j==1); echo on; end
    mse_av = mse_av + mse;
    echo off;
end; 
  end
-----------------------

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Guillaume 2017-9-6

编辑：Guillaume 2017-9-6

To provide a meaningful answer, we would have to retype the code you've provided in your screenshot, since it's not possible to copy text from a picture. That's a large burden you're putting onto us.

Instead of an image, copy/paste your code as text, using the {}Code button to format it as code.

As for the question, I'm not sure what you mean by plotting the shifting. What do you want to see in your plot? What's on the x axis, what's on the y axis?

Rock Rocky 2017-9-6

I would like to plot c and d of the if statement with respect to the filter length. in order to prove that the algorithm is working and shifting between the two step size values c and d according to the if statement

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Answer 1

dpb 2017-9-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/355401-plot-shifting-between-two-values-in-if-statement#answer_280452

在 MATLAB Online 中打开

...
for k=1:N-2*K,
   ...
   if(e_k>e_k1)
     estimated_c=estimated_c+(c)*e_k*y_k/n;
     plot(k,estimated_c,'rx')
   elseif(e_k<=e_k1)
     estimated_c=estimated_c+(d)*e_k*y_k/n;
     plot(k,estimated_c,'go')
   end
   if k==1,hold on,end
   ...