I am getting Error using l1eq_pd

??? Undefined function or method 'l1eq_pd' for input arguments of type
'double'.

Error in ==> dspproject at 53
xp = l1eq_pd(x0,A,[],y,1e-2);

My code is

clc;
clear all;
Fs=10000;
x=wavread('speech3_10k');
figure(1)
stem(x)
title( 'input speech signal(recorded)');
xlabel('Length of the input speech signal');
ylabel('Amplitude of the input speech signal');
% Reecorded signal DCT
drec=dct(x);
figure(2)
stem(drec)
axis([0 3000 -1 1]);
title('Discrete cosine transform of the recorded signal');
xlabel('DCT Length');
ylabel('DCT amplitude');
% Making a signal sparse (Thresholding)
for i=1:1:3000;
if drec(i,1)<=0.08 && drec(i,1)>=0.04
drec(i,1)=0;
else
drec(i,1)=drec(i,1);
end
end
drec;
figure(3)
stem(drec)
axis([0 3000 -1 1]);
title('The Threshold spectrum');
xlabel('threshold spectrum length');
ylabel('threshold spectrum amplitude');
% K=>sparsity & N=>length)
K=64;
N=320;
% Random measurement matrix
A = randn(2,24006);
A = orth(A')';
figure(4)
imagesc(A)
colorbar;
colormap('lines');
title('Random Measurement matrix');
% observations vector
y = A*drec; 
figure(5)
plot(y)
title('Observation Vector');
%initial guess = min energy
x0 = A'*y;
%solve the LP
tic
xp = l1eq_pd(x0,A,[],y,1e-2);
toc
figure(6)
plot(xp)
axis([0 3000 -0.6 0.6]);
title(' Reconstructed Spectrum using l1-minimization');
% Inv dicrete cosine transform of reconstructed signal
Xrec=idct(xp);
wavplay(Xrec,Fs)
figure(7)
stem(Xrec)
title('Reconstructed signal at the receiver');
xlabel('Length of the reconstructed signal');
ylabel('Amplitude of the reconstructed signl');
% Absolute error between the reconstructed and actual signal
err=(max(abs(Xrec-x)));
stem(err);
title(' Absolute Error');
xlabel('Maximum Absolute Error length');
ylabel('Maximum Absolute error')

[Geoff Hayes]

Hi Manipal,

It almost sounds like your are missing the function l1eq_pd which is typically what this error implies. From the command line type:

help l1eq_pd

What is returned? Is there a description for this function? If not, then the function is missing.

Geoff

[Manipal Reddy Kuchakuntla]

I got to use the l1eq function. But the code I am trying execute isn't going good. Can anyone help me out.

When I am playing Xrec{wavplay(Xrec)};it is not the desired output. Its just a beep sound.

[Manipal Reddy Kuchakuntla]

I got to use the l1eq function. But the code I am trying execute isn't going good. Can anyone help me out.

When I am playing Xrec{wavplay(Xrec)};it is not the desired output. Its just a beep sound.

Answer 1

[Star Strider]

Go here: MATLAB Compressive Sensing Tutorial or here: SPARSE ESTIMATION Sparse signal recovery via L_1 minimization.

[Manipal Reddy Kuchakuntla]

I got some code from the links you gave me. But are they true for all. Or there is separate code for each and every equation.

Thank You

[Star Strider]

My pleasure!

I did an Internet search for the file you were missing, and at least one of those promised to have it.

[Manipal Reddy Kuchakuntla]

I got to use the l1eq function. But the code I am trying execute isn't going good. Can anyone help me out.

When I am playing Xrec{wavplay(Xrec)};it is not the desired output. Its just a beep sound.

Answer 2

[Shreyas Shenoy]

If you want to use the l1eq_pd function without errors, here's what you have to do!

Step 1:

• Go to http://statweb.stanford.edu/~candes/l1magic/
• Download the code.
• Unzip the folder into one of your choice. (For reference to the next step, mine is in D:\BIT ETSIT UPM\06.18)

Step 2:

• Open MATLAB. Click on 'Set path' option.

Step 3:

• Click on the option "Add with sub folders" and then select the folder "l1 magic" in the new window that opens.

Finally : Click on save once this window opens.

And now, you are good to go! :-)

Answer 3

[Manipal Reddy Kuchakuntla]

Hi Geoff

Yes I have a problem with the function. There is no such function.

What is that I can do. Help me out. Thank You Manipal

Answer 4

[Manipal Reddy Kuchakuntla]

I got to use the l1eq function. But the code I am trying execute isn't going good. Can anyone help me out.

When I am playing Xrec{wavplay(Xrec)};it is not the desired output. Its just a beep sound.