dwpt.sim(waveslim)
dwpt.sim()所属R语言包:waveslim
Simulate Seasonal Persistent Processes Using the DWPT
模拟季节性持久的过程,使用DWPT
译者:生物统计家园网 机器人LoveR
描述----------Description----------
A seasonal persistent process may be characterized by a spectral density function with an asymptote occuring at a particular frequency in [0,1/2). It's time domain representation was first noted in passing by Hosking (1981). Although an exact time-domain approach to simulation is possible, this function utilizes the discrete wavelet packet transform (DWPT).
由谱密度函数,其特征在于一个季节性的持久性过程可与渐近线在[0,1/2)在某一特定频率发生。通过霍斯金(1981)首先注意到的时域表示。虽然确切的时域模拟的方法是可行的,该功能采用了离散小波包变换(DWPT“)。
用法----------Usage----------
参数----------Arguments----------
参数:N
Length of time series to be generated.
要生成的时间序列的长度。
参数:wf
Character string for the wavelet filter.
小波滤波器的字符串。
参数:delta
Long-memory parameter for the seasonal persistent process.
术语记忆参数的季节性持续的过程。
参数:fG
Gegenbauer frequency.
盖根堡的频率。
参数:M
Actual length of simulated time series.
模拟时间序列的实际长度。
参数:adaptive
Logical; if TRUE the orthonormal basis used in the DWPT is adapted to the ideal spectrum, otherwise the orthonormal basis is performed to a maximum depth.
逻辑;如果TRUE的标准正交基用于在DWPT的适应的理想光谱,否则标准正交基进行的最大深度。
参数:epsilon
Threshold for adaptive basis selection.
阈值自适应的基础上选择。
Details
详细信息----------Details----------
Two subroutines are used, the first selects an adaptive orthonormal basis for the true spectral density function (SDF) while the second computes the bandpass variances associated with the chosen orthonormal basis and SDF. Finally, when \code{M} > \code{N} a uniform random variable is generated in order to select a random piece of the simulated time series. For more details see Whitcher (2001).
两个子程序被使用时,首先选择的自适应功能(SDF)的真正的谱密度的标准正交基,而第二计算与所选择的标准正交基和SDF相关的带通方差。最后,当\code{M} > \code{N}产生一个均匀分布的随机变量,以便选择一个随机的一块上的模拟时间系列。有关详细信息,请参阅Whitcher(2001年)。
值----------Value----------
Time series of length N.
时间序列长度N。
(作者)----------Author(s)----------
B. Whitcher
参考文献----------References----------
Fractional Differencing, Biometrika, 68, No. 1, 165-176.
Simulating Gaussian Stationary Time Series with Unbounded Spectra, Journal of Computational and Graphical Statistics, 10, No. 1, 112-134.
参见----------See Also----------
hosking.sim for an exact time-domain method and wave.filter for a list of available wavelet filters.
hosking.sim一个确切的时域法和wave.filter的列表,可用的小波滤波器。
实例----------Examples----------
## Generate monthly time series with annual oscillation[#生成月度时间序列,每年振荡]
## library(ts) is required in order to access acf()[#库(TS)是必需的,以便访问ACF()]
x <- dwpt.sim(256, "mb16", .4, 1/12, M=4, epsilon=.001)
par(mfrow=c(2,1))
plot(x, type="l", xlab="Time")
acf(x, lag.max=128, ylim=c(-.6,1))
data(acvs.andel8)
lines(acvs.andel8$lag[1:128], acvs.andel8$acf[1:128], col=2)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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