hi, i have problem with my program. How do i resolve waverec error? need help

[Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('db6');

[C,L] = wavedec(ecgsmooth,8,Lo_D,Hi_D);

[d1,d2,d3,d4,d5,d6,d7,d8]=detcoef(C,L,[1,2,3,4,5,6,7,8]);

A8 = wrcoef('a',C,L,Lo_R,Hi_R,8);

A6 = wrcoef('a',C,L,Lo_R,Hi_R,6);

A7 = wrcoef('a',C,L,Lo_R,Hi_R,7);

A5 = wrcoef('a',C,L,Lo_R,Hi_R,5);

A4 = wrcoef('a',C,L,Lo_R,Hi_R,4);

A3 = wrcoef('a',C,L,Lo_R,Hi_R,3);

A2 = wrcoef('a',C,L,Lo_R,Hi_R,2);

A1 = wrcoef('a',C,L,Lo_R,Hi_R,1);

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

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

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

D4 = wrcoef('d',C,L,Lo_R,Hi_R,4);

D5 = wrcoef('d',C,L,Lo_R,Hi_R,5);

D6 = wrcoef('d',C,L,Lo_R,Hi_R,6);

D7 = wrcoef('d',C,L,Lo_R,Hi_R,7);

D8 = wrcoef('d',C,L,Lo_R,Hi_R,8);

[Loo_D,Hii_D,Loo_R,Hii_R] = wfilters('db6');

[C,L] = wavedec(ppgsmooth,8,Loo_D,Hii_D);

[d1,d2,d3,d4,d5,d6,d7,d8]=detcoef(C,L,[1,2,3,4,5,6,7,8]);

A_8 = wrcoef('a',C,L,Loo_R,Hii_R,8);

A_6 = wrcoef('a',C,L,Loo_R,Hii_R,6);

A_7 = wrcoef('a',C,L,Loo_R,Hii_R,7);

A_5 = wrcoef('a',C,L,Loo_R,Hii_R,5);

A_4 = wrcoef('a',C,L,Loo_R,Hii_R,4);

A_3 = wrcoef('a',C,L,Loo_R,Hii_R,3);

A_2 = wrcoef('a',C,L,Loo_R,Hii_R,2);

A_1 = wrcoef('a',C,L,Loo_R,Hii_R,1);

D_1 = wrcoef('d',C,L,Loo_R,Hii_R,1);

D_2 = wrcoef('d',C,L,Loo_R,Hii_R,2);

D_3 = wrcoef('d',C,L,Loo_R,Hii_R,3);

D_4 = wrcoef('d',C,L,Loo_R,Hii_R,4);

D_5 = wrcoef('d',C,L,Loo_R,Hii_R,5);

D_6 = wrcoef('d',C,L,Loo_R,Hii_R,6);

D_7 = wrcoef('d',C,L,Loo_R,Hii_R,7);

D_8 = wrcoef('d',C,L,Loo_R,Hii_R,8);

tr = 'sqtwolog';

thr_D1 = thselect(D1,tr);

thr_D2 = thselect(D2,tr);

thr_D3 = thselect(D3,tr);

thr_D4 = thselect(D4,tr);

thr_D5 = thselect(D5,tr);

thr_D6 = thselect(D6,tr);

thr_D7 = thselect(D7,tr);

thr_D8 = thselect(D8,tr);

tD1 = wthresh(D1,'h',thr_D1);

tD2 = wthresh(D2,'h',thr_D2);

tD3 = wthresh(D3,'h',thr_D3);

tD4 = wthresh(D4,'h',thr_D4);

tD5 = wthresh(D5,'h',thr_D5);

tD6 = wthresh(D6,'h',thr_D6);

tD7 = wthresh(D7,'h',thr_D7);

tD8 = wthresh(D8,'h',thr_D8);

thr_D1_ = thselect(D_1,tr);

thr_D2_ = thselect(D_2,tr);

thr_D3_ = thselect(D_3,tr);

thr_D4_ = thselect(D_4,tr);

thr_D5_ = thselect(D_5,tr);

thr_D6_ = thselect(D_6,tr);

thr_D7_ = thselect(D_7,tr);

thr_D8_ = thselect(D_8,tr);

tD1_ = wthresh(D1,'h',thr_D1_);

tD2_ = wthresh(D2,'h',thr_D2_);

tD3_ = wthresh(D3,'h',thr_D3_);

tD4_ = wthresh(D4,'h',thr_D4_);

tD5_ = wthresh(D5,'h',thr_D5_);

tD6_ = wthresh(D6,'h',thr_D6_);

tD7_ = wthresh(D7,'h',thr_D7_);

tD8_ = wthresh(D8,'h',thr_D8_);

ApECG = A3 - A7;

ECSignal = waverec((ApECG + tD3 + tD4 + tD5 + tD6),8,Lo_R,Hi_R);

ApPPG = A_8;

PPSignal = waverec((ApPPG + tD3_ + tD4_ + tD5_ + tD6_),8,Loo_R,Hii_R);

ERROR

Error using appcoef

Expected N to be a scalar with value <= -1.

Error in appcoef (line 59)

validateattributes(n,{'numeric'},...

Error in waverec (line 23)

x = appcoef(c,l,varargin{:},0);

Error in Ekstraksi (line 84)

ECSignal = waverec((ApECG + tD3 + tD4 + tD5 + tD6),8,Lo_R,Hi_R);

Answer 1

[Pruthvi Charka]

Hi,

I understand that you are trying to use waverec function and encountered an error. The code you have provided is not executable since it contains undefined variables “ecgsmooth” and “ppgsmooth”.

However, it looks like you have passed incorrect value as the second input argument. The waverec function expects bookkeeping vector as the second argument. This vector is used to parse the wavelet coefficients passed in the first argument.

Please refer the waverec function documentation linked below for more details:

https://in.mathworks.com/help/wavelet/ref/waverec.html

Hope this helps!