Mexican hat wavelet


[PSI,X] = mexihat(LB,UB,N)


[PSI,X] = mexihat(LB,UB,N) returns values of the Mexican hat wavelet on an N point regular grid, X, in the interval [LB,UB].

Output arguments are the wavelet function PSI computed on the grid X.

This wavelet has [-5 5] as effective support. Although [-5 5] is the correct theoretical effective support, a wider effective support, [-8 8], is used in the computation to provide more accurate results.

This function is proportional to the second derivative function of the Gaussian probability density function.


% Set effective support and grid parameters. 
lb = -5; ub = 5; n = 1000; 

% Compute and plot Mexican hat wavelet. 
[psi,x] = mexihat(lb,ub,n); 
plot(x,psi), title('Mexican hat wavelet')

See Also

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