This is machine translation

Translated by Microsoft
Mouse over text to see original. Click the button below to return to the English verison of the page.


Mexican hat (Ricker) 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]. The Mexican hat wavelet is also known as the Ricker wavelet.

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.

    Note:   You can use gauswavf to obtain a second order derivative of a Gaussian wavelet. If you use the negative of this normalized derivative, the resulting wavelet resembles the Mexican hat wavelet.


collapse all

Create a Mexican hat wavelet with support on [-5,5]. Use 1,000 sample points. Plot the result.

lb = -5;
ub = 5;
N = 1000;
[psi,xval] = mexihat(lb,ub,N);
title('Mexican Hat Wavelet');

See Also

Introduced before R2006a

Was this topic helpful?