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clc; clear; close all;

load sumsin;
x = sumsin(1:500);
x = x + randn(1, length(x));
Fs = 10;
figure;     cwt(x, 'amor');     % 不指定Fs
figure;     cwt(x, 'amor', Fs);     % 指定Fs

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clc; clear; close all;

load sumsin;
x = sumsin(1:500);
x = x + randn(1, length(x));
Fs = 10;
[wt, f] = cwt(x, 'amor', Fs);     % 指定Fs
xrec1 = icwt(wt, 'amor');       % 反变换，指定小波基
xrec2 = icwt(wt, f, [0.06, 0.31]);       % 反变换，指定频率范围可实现滤波效果。

subplot(311);   plot(x);        title('x');
subplot(312);   plot(xrec1);    title('全频率小波逆变换')
subplot(313);   plot(xrec2);    title('针对部分频率范围进行小波逆变换')

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clear all;
load sumsin;
x = sumsin(1:500);
[cA, cD] = dwt(x, 'db2');
x_idwt = idwt(cA, cD, 'db2');

subplot(411);   plot(x);    title('x');
subplot(412);   plot(cA);   title('cA of dwt'); xlim([1, length(x)]);
subplot(413);   plot(cD);   title('cD of dwt'); xlim([1, length(x)]);
subplot(414);   plot(x_idwt);   title('idwt'); xlim([1, length(x)]);

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clear; 

load sumsin;
x = sumsin(1:500);
[c, l] = wavedec(x, 3, 'db3');
subplot(521);	plot(x);    title('x');   xlim([1, length(x)]);

xx = waverec(c,l,'db3');
subplot(522);	plot(x);    title('waverec重构信号');   xlim([1, length(x)]);

subplot(523);   plot(c);    title('wavedec-3个尺度分解结果');   xlim([1, length(x)]);

for i=1:3
    a1 = wrcoef('a', c, l, 'db3', i);      % a-低频重构，d-高频重构
    subplot(5,2, 2*i + 3);   plot(a1);    
    title(['wrcoef-从第', num2str(i),'个尺度的低频分量重构到0级']);   xlim([1, length(x)]);
end

for i=1:3
    a1 = wrcoef('d', c, l, 'db3', i);      % a-低频重构，d-高频重构
    subplot(5,2, 2*i + 4);   plot(a1);    
    title(['wrcoef-从第', num2str(i),'个尺度的高频分量重构到0级']);   xlim([1, length(x)]);
end