MATLAB: How dwt and wavedec are different ? here why cA1 and C have diffrent values

Question

data=xlsread('E:\color\neha.xlsx');

data= data';

value1=data(1,:);

chan1= value1-mean(value1);

[cA1,cD1] = dwt(chan1,'db4');

[cA2,cD2] = dwt(cA1,'db4');

[cA3,cD3] = dwt(cA2,'db4');

[cA4,cD4] = dwt(cA3,'db4');

[cA5,cD5] = dwt(cA4,'db4');

[cA6,cD6] = dwt(cA5,'db4');

[cA7,cD7] = dwt(cA6,'db4');

[cA8,cD8] = dwt(cA7,'db4');

[cA9,cD9] = dwt(cA8,'db4');

[cA10,cD10] = dwt(cA9,'db4');

[C,L] = wavedec(chan1,10,'db4');

Answer 1

As you see, dwt() gives only a level 1 DWT, while wavedec gives you multiple levels. But you are correct that wavedec() simply iterates on the approximation coefficients of the previous level as expected.

Why do you say they are different? I do not see it. The first L(1) elements of wavedec should equal cA10 above

chan1 = randn(1024,1);
[cA1,cD1] = dwt(chan1,'db4');
[cA2,cD2] = dwt(cA1,'db4');
[cA3,cD3] = dwt(cA2,'db4');
[cA4,cD4] = dwt(cA3,'db4');
[cA5,cD5] = dwt(cA4,'db4');
[cA6,cD6] = dwt(cA5,'db4');
[cA7,cD7] = dwt(cA6,'db4');
[cA8,cD8] = dwt(cA7,'db4');
[cA9,cD9] = dwt(cA8,'db4');
[cA10,cD10] = dwt(cA9,'db4');
[C,L] = wavedec(chan1,10,'db4');

Now compare:

   C(1:L(1))

with

   cA10

Likewise, compare

C(L(1)+1:L(1)+L(2))

with

cD10