This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English version of the page.

Note: This page has been translated by MathWorks. Please click here
To view all translated materials including this page, select Japan from the country navigator on the bottom of this 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.


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?