小波函數(shù)及Matlab常用指令

1、( )x、和其他012/ 112/ 101xxH在命令窗口輸入waveinfo(haar)2、db系列小波2/2cos5xxCex（ ）2/224/1)1 (32xexx）（lo_d,hi_d,lo_r,hi_r=wfilters(db2);ca,cd=dwt(s,lo_d,hi_d);x2=idwt(ca,cd,lo_r,hi_r);subplot(6,2,9);plot(x2);title(濾波器重構(gòu))errx2max=max(abs(s-x2)errx2=s-x2;subplot(6,2,10);plot(errx2)title(濾波器重構(gòu)誤差);axis(0,1000,-2e-11,2

2、e-11);11,jjjca cd cdcd11,jjjcacdcdcd的長(zhǎng)度的長(zhǎng)度的長(zhǎng)度的長(zhǎng)度xca1cd1ca2cd2ca3cd3ca3cd3cd2cd1C:L:ca3的長(zhǎng)度 cd3的長(zhǎng)度 cd2的長(zhǎng)度 cd1的長(zhǎng)度 x的長(zhǎng)度L= 125 125 250 500 1000等效于NL=250 250 500 1000L= 125 125 250 500 1000Tree Decomposition(0,0)(1,0)(1,1)(2,0)(2,1)(2,2)(2,3)(3,0)(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)(3,7)2004006008001000-10-8-6-

3、4-20246810data for node: (0) or (0,0).Tree Decomposition(0,0)(1,0)(1,1)(2,0)(2,1)(2,2)(2,3)(3,0)(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)(3,7)100200300400500-15-10-5051015data for node: (1) or (1,0).Tree Decomposition(0,0)(1,0)(1,1)(2,0)(2,1)(2,2)(2,3)(3,0)(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)(3,7)100200300400500-4-3

4、-2-10123data for node: (2) or (1,1).Tree Decomposition(0,0)(1,0)(1,1)(2,0)(2,1)(2,2)(2,3)(3,0)(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)(3,7)50100150200250-15-10-505101520data for node: (3) or (2,0).Tree Decomposition(0,0)(1,0)(1,1)(2,0)(2,1)(2,2)(2,3)(3,0)(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)(3,7)50100150200250-4-3-2

5、-1012345data for node: (4) or (2,1).Tree Decomposition(0,0)(1,0)(1,1)(2,0)(2,1)(2,2)(2,3)(3,0)(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)(3,7)50100150200250-4-3-2-10123data for node: (5) or (2,2).Tree Decomposition(0,0)(1,0)(1,1)(2,0)(2,1)(2,2)(2,3)(3,0)(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)(3,7)50100150200250-3-2-10123

6、4data for node: (6) or (2,3).Tree Decomposition(0,0)(1,0)(1,1)(2,0)(2,1)(2,2)(2,3)(3,0)(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)(3,7)20406080100120-25-20-15-10-505101520data for node: (7) or (3,0).subplot(323);plot(cfs21);title(小波包2,1的系數(shù));subplot(324);plot(cfs22);title(小波包2,2的系數(shù));subplot(325);plot(cfs31);title(小波包3,1的系數(shù));subplot(326);plot(cfs32);title(小波包3,2的系數(shù));020040060080010001200-10-50510原 始 信 號(hào)050100150200250300-20-1001020小 波 包 2,0的 系 數(shù)050100150200250300