Error using wavedec Expected X to be finite. Error in wavedec (line 34) validateat​tributes(x​,{'numeric​'},{'vecto​r','finite​','real'},​'wavedec',​'X');

I am using wavedec to discritize my signal using 'db4' wavelet.

my X = acceleration vector(9000 x 1)

My X is finite. But I am getting a error that ' Error using wavedec Expected X to be finite'

My code :

[a,l] = wavedec(acc,3,'db4');

approx = appcoef(a,l,'db4');

[acd1,acd2,acd3] = detcoef(a,l,[1 2 3]);

figure

subplot(4,1,1)

plot(approx)

title('Approximation Coefficients')

subplot(4,1,2)

plot(acd3)

title('Level 3 Detail Coefficients')

subplot(4,1,3)

plot(acd2)

title('Level 2 Detail Coefficients')

subplot(4,1,4)

plot(acd1)

title('Level 1 Detail Coefficients')

please help me. Where I am wrong. I am unable to solve this problem.