following code is used for filter? if yes, what is the type of filter can u help me ? wavedec and appcoef use for filter?

if flag==2
                      flag=3;
                      [c,l]=wavedec(nfile,8,'db8');
                      ca1=appcoef(c,l,'db8',1);
                      ca2=appcoef(c,l,'db8',2);
                      ca3=appcoef(c,l,'db8',3);
                      ca4=appcoef(c,l,'db8',4);
                         figure(2),plot(ca1,'-k'),title('Cofficients of Signal At l Level Decomposition')
                          figure(3),plot(ca2,'-k'),title('Cofficients of Signal At 2 Level Decomposition')
                           figure(4),plot(ca3,'-k'),title('Cofficients of Signal At 3 Level Decomposition')
                            figure(5),plot(ca4,'-r'),title('Cofficients of Signal At 4 Level Decomposition')
                            flag=3 ;
                  else
                      errordlg('First select ECG Signal')
                  end