V-system is a kind of complete orthogonal piecewise polynomial function system on L2[0,1], because of the discontinuous nature of its basis functions, it has significant advantages in the expression and analysis of discontinuous signals. However, in the current V-system transformation algorithm, for a signal with a length of N, it not only needs to generate and store an N-order orthogonal matrix in advance, but also its time complexity is as high as Ο(N3). Therefore, in order to adapt to the efficient processing needs, this paper designs and implements a fast decomposition and reconstruction algorithm for V-systems from the perspective of multi-resolution analysis of V-systems. This fast algorithm does not need to store additional information, and its time complexity is only Ο(N2). The test results show that the fast algorithm proposed in this paper can meet the requirements of high-efficiency processing of large-scale data, which lays the foundation for the application of V-system in more fields.
Wei CHEN,Jinwen QI,Jian LI,Ruixia SONG. A fast algorithm for V-system. Journal of Zhejiang University (Science Edition), 2023, 50(6): 761-769.
https://www.zjujournals.com/sci/EN/Y2023/V50/I6/761
V-系统是L2[0,1]上的一类完备正交分段多项式函数系,由于其基函数的间断特性,在非连续信号的表达与分析上优势显著。然而,在目前的V-系统变换算法中,对于一个长度为N的信号,不仅需要事先生成并存储一个N阶的正交矩阵,而且其时间复杂度高达Ο(N3)。为实现对大规模数据的高效处理,从V-系统的多分辨率分析角度出发,设计并实现了V-系统的快速分解与重构算法,不仅无须存储额外信息,而且其时间复杂度仅为Ο(N)。测试结果表明,提出的快速算法能够满足大规模数据高效处理要求,为V-系统在更多领域的应用奠定了基础。
尺度空间V0
?k0x,?k1x,?????,?kkx
小波空间W0
ψk,00,0x,ψk,00,1x,?????,ψk,00,kx
小波空间W1
ψk,1j,ix=2ψk,00,i(2x-j),????x∈j2,j+12,0,????其他,
i=0,1,2,?,k;j=0,1
小波空间W2
ψk,2j,ix=2ψk,00,i(4x-j),????x∈j4,j+14,0,????其他,
i=0,1,2,?,k;j=0,1,2,3
小波空间Wn
ψk,nj,ix=2ψk,00,i(2nx-j),????x∈j2n,j+12n,0,????其他,
i=0,1,2,?,k;j=0,1,3,?,2n-1
Cited