matlab中，如何用wavefun画dbN、Morlet、MexicanHat、sym小波基图？

更改小波基的名称，dbN，symN和coifN是正交小波基，是有尺信亮度函数的，只更改N就行，如

[phi,psi,x] = wavefun('sym4',10)%建议使用10次以上迭代计算，比较精确

subplot(211),plot(x,phi)%尺度函数

subplot(212),plot(x,psi)%小波函数

Morlet(Morl)、MexicanHat(mexh)是没有尺度函数定义的小波基，只能显示其小波函数，

[psi,x] = wavefun('Morl',10)

subplot(212),plot(x,psi)%小庆悔波函数

参看matlab对wavefun的帮助文档即可，对各种类型的小波基的誉坦正格式有很详细的说明。

在EDIT控件内只需按照普通矩阵输入方法进行输入，例如：1，2，3；1，2，3 然后在进行处理即可得到做袭数组。 MATLAB内面的变量都是矩阵，无论是族备一个数还是数组，还是多维数组，都是矩阵组成的，所以MATLAB中强烈建议不要使用FOR循环之类的兆胡毁，直接矩阵...

Matlab之小波滤波函数 :

1 wfilters函数

[Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('wname') computes four filters associated with the orthogonal or biorthogonal wavelet named in the string 'wname'. The four output filters are

Lo_D, the decomposition low-pass filter Hi_D, the decomposition high-pass filter Lo_R, the reconstruction low-pass filter

　备雹　Hi_R, the reconstruction high-pass filter

2 biorfilt函数

The biorfilt command returns either four or eight filters associated with biorthogonal wavelets.

3 orthfilt函数咐肢

[Lo_D,Hi_D,Lo_R,Hi_R] = orthfilt(W) computes the four filters associated with the scaling filter W corresponding to a wavelet

4 biorwaef函数

[RF,DF] = biorwavf(W) returns two scaling filters associated with the biorthogonal wavelet specified by the string W.

5 coifwavf函数

F = coifwavf(W) returns the scaling filter associated with the Coiflet wavelet specified by the string W where W = 'coifN'. Possible values for N are 1, 2, 3, 4, or 5

6 dbaux函数

W = dbaux(N,SUMW) is the order N Daubechies scaling filter such that sum(W) = SUMW. Possible values for N are 1, 2, 3, ...

W = dbaux(N) is equivalent to W = dbaux(N,1) W = dbaux(N,0) is equivalent to W = dbaux(N,1)

7 dbwavf函数衡滚世

F = dbwavf(W) returns the scaling filter associated with Daubechies wavelet specified by the string W where W = 'dbN'. Possible values for N are 1, 2, 3, ..., 45.

8 mexihat函数

[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.

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