detcoef - One Dimension Detail Coefficent Extraction
detcoef is for extraction of detail coeffient at different level after a multiple level decompostion. Extension mode is stored as a global variable and could be changed with dwtmode. If N is omitted, maximum level approximation will be obtained.
x=rand(1,100); [C,L]=wavedec(x,3,'db2'); D2=appcoef(c,l,2);
Roger Liu and Isaac Zhi