how to normalize a signal to zero mean and unit variance

i'm trying to normalize EHG signal's wavelet components to zero mean and unit variance,and i have used

 cA3=reshape(zscore(cA3(:)),size(cA3,1),size(cA3,2));

this matlab expression,and got an answer like this

>> mean2(cA3(:))

ans =

       -2.84121591248158e-16
  >> var(cA3(:))

ans =

                           1

[sahana kp]

how can i normalize the wavelet component with respect to other wavelet components to zero mean and unit variance..

term_dat1=importdata('tpehg1022m.mat');

term_dat1=term_dat1';
tdat1=term_dat1(:,1);
[cA1,cH1,cV1,cD1] = dwt2(tdat1,'db4');
[cA2,cH2,cV2,cD2] = dwt2(cA1,'db4');
[cA3,cH3,cV3,cD3] = dwt2(cA2,'db4');
DWT_feat = [cA3,cH3,cV3,cD3];

 cA3=reshape(zscore(cA3(:)),size(cA3,1),size(cA3,2));
 cH3=reshape(zscore(cH3(:)),size(cH3,1),size(cH3,2));
 cV3=reshape(zscore(cV3(:)),size(cV3,1),size(cV3,2));
 cD3=reshape(zscore(cD3(:)),size(cD3,1),size(cD3,2));

is this code enough ?

Answer 1

[Walter Roberson]

Those values are normalized. The 1e-16 is due to limitations in floating point calculation