is my code are correct?? multilevel wavelet and feature extraction

i want to use wavelet to decomposed the signal at certain detail then classify the detail of signal using parseval theorm.

. The proposed classification method is doneusing unique patterns. The difference be-tween the discrete wavelet coefficients of theanalyzed signal and a pure signal at each levelwill be computed, and the result will bedivided by the total energy of the correspond-ing pure signal for normalization purposes,and then multiplied by 100 to have apercentage ratio. but i keep getting error for my coding. is anyone can point out what is the problem with this code??

% multilevel wavelet

x = (voltage(:,1:718));

l_s = length (x)

[C,L] = wavedec( x, 3, 'db1');

% extract level 3 approximation

cA3 = appcoef(C,L,'db1',3);

%extract the levels 4,3, 2, and 1 detail coefficients from C, type:

[cD1,cD2,cD3] = detcoef(C,L,[1,2,3]);

figure (1);

figure(1); subplot(211);

plot(x); title('Original signal');

subplot(1,2,1); plot(D1); title('Detail D1')

subplot(1,2,1); plot(D2); title('Detail D2')

subplot(1,2,1); plot(D3); title('Detail D3')

%reconstruct the details at levels 1, 2 and 3, from C, type:

D1 = wrcoef('d',C,L,'db1',1);

D2 = wrcoef('d',C,L,'db1',2);

D3 = wrcoef('d',C,L,'db1',3);

%display the results of the level 3 decomposition, type:

subplot(2,2,1); plot(A3);

title('Approximation A3')

subplot(2,2,2); plot(D1);

title('Detail D1')

subplot(2,2,3); plot(D2);

title('Detail D2')

subplot(2,2,4); plot(D3);

title('Detail D3')

--------------------------------------------------------------------- %apply parseval theorm

% N= no. of sample

% J = no. of approximate level

% aj = approximate version signal

% dj = detail version signal

symsum((cA3),k,1,N)= symsum((cA^2),k,1,N)+ symsum((symsum((cD^2),k,1,N)),i,1,J);

[Image Analyst]

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