wrcoef('ty​pe',C,L,'w​name',N) When 'type' = 'd', is N allowed to be 0？？？

 When 'type' = 'a', N is allowed to be 0; 
when ‘type'='d'  ,N ??

Answer 1

[Wayne King]

In that case, you are asking for a reconstruction based on the wavelet coefficients, so the level, N, has to be >= 1

Of course, how large N can be depends on the level you used in obtaining C,L from wavedec()