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R语言 tsDyn包 llar()函数中文帮助文档(中英文对照)

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发表于 2012-10-1 12:32:53 | 显示全部楼层 |阅读模式
llar(tsDyn)
llar()所属R语言包:tsDyn

                                        Locally linear model
                                         局部线性模型

                                         译者:生物统计家园网 机器人LoveR

描述----------Description----------

Casdagli test of nonlinearity via locally linear forecasts
通过局部线性预测的非线性Casdagli测试


用法----------Usage----------


llar(x, m, d = 1, steps = d, series, eps.min = sd(x)/2,
        eps.max = diff(range(x)), neps = 30, trace = 0)

llar.predict(x, m, d=1, steps=d, series, n.ahead=1,
eps=stop("you must specify a window value"),
onvoid=c("fail","enlarge"), r = 20, trace=1)

llar.fitted(x, m, d=1, steps=d, series, eps, trace=0)



参数----------Arguments----------

参数:x
time series  
时间序列


参数:m, d, steps
embedding dimension, time delay, forecasting steps  
嵌入维,时间延迟,预测的步骤


参数:series
time series name (optional)
时间序列的名称(可选)


参数:n.ahead
n. of steps ahead to forecast  
N。提前预测的步骤


参数:eps.min, eps.max
min and max neighbourhood size  
最小和最大邻域大小


参数:neps
number of neighbourhood levels along which iterate
附近水平,以及会遍历数


参数:eps
neighbourhood size  
邻域大小


参数:onvoid
what to do in case of an isolated point: stop or enlarge neighbourhood size by an r%
在一个孤立点的情况下该怎么做:停止或扩大邻域大小由R%


参数:r
if an isolated point is found, enlarge neighbourhood window by r%
如果发现一个孤立的点,扩大邻域窗口R%


参数:trace
tracing level: 0, 1 or more than 1 for llar, 0 or 1 for llar.forecast
跟踪级别:0,1或大于1llar,0或1llar.forecast


Details

详细信息----------Details----------

llar does the Casdagli test of non-linearity. Given the embedding state-space (of dimension m and time delay d) obtained from time series series, for a sequence of distance values eps, the relative error made by forecasting time series values with a linear autoregressive model estimated on points closer than eps is computed.  If minimum error is reached at relatively small length scales, a global linear model may be inappropriate (using current embedding parameters). This was suggested by Casdagli(1991) as a test for non-linearity.
llar做Casdagli的非线性度测试。由于嵌入状态空间(维m和时间延迟d)得到的距离值的序列的时间序列series,eps,相对误差作出的时间序列预测值的线性回归模型估计比eps计算。如果达到最小误差为一个全球性的线性模型可以在相对较小的尺度,是不恰当的(使用电流嵌入参数)。这建议者Casdagli(1991)作为试验为非线性。

llar.predict tries to extend the given time series by n.ahead points by iteratively  fitting locally (in the embedding space of dimension m and time delay d) a linear model. If the spatial neighbourhood window is too small, your time series last point would be probably isolated. You can ask to automatically enlarge the window eps by a factor of r% sequentially, until enough neighbours are found for fitting the linear model.
llar.predictn.ahead点尝试延长给定的时间序列,通过迭代地嵌合在本地(在嵌入空间的维数m和时间延迟d)一个线性模型。如果空间邻域窗口太小,时间序列的最后一点可能会分离出来。你可以要求自动放大窗口eps的r%,比上一季度的一个因素,直到有足够的邻居发现拟合的线性模型。

llar.fitted gives out-of-sample fitted values from locally linear models.
llar.fitted给出了样本的局部线性模型的拟合值。


值----------Value----------

llar gives an object of class 'llar'. I.e., a list of components:
llar给出了的对象类的llar“。即,组件的列表:


参数:RMSE
vector of relative errors
相对误差向量


参数:eps
vector of neighbourhood sizes (in the same order of RMSE)
矢量附近的大小(以相同的顺序,RMSE)


参数:frac
vector of fractions of the time series used for RMSE computation
用零碎的时间序列向量计算RMSE


参数:avfound
vector of average number of neighbours for each point in the time series  which can be plotted using the plot method, and transformed to a regular data.frame with the as.data.frame function.
矢量的时间序列中的可以使用plot方法绘制,并转化到定期data.frameas.data.frame函数平均数为每个点的邻居。

Function llar.forecast gives the vector of n steps ahead locally linear iterated forecasts.
函数llar.forecast给出的向量n步未来局部线性迭代预测。

Function llar.fitted gives out-of-sample fitted values from locally linear models.
功能llar.fitted给出了样本局部线性模型的拟合值。


警告----------Warning----------

For long time series, this can be slow, especially for relatively big neighbourhood sizes.
长的时间序列,这可能是缓慢的,尤其是对于比较大的区域的大小。


注意----------Note----------

The C implementation was re-adapted from that in the TISEAN package ("ll-ar" routine, see references). However, here the euclidean norm is used, in place of the max-norm.
C实现重新改编自,在TISEAN包(“LL-ar”的常规,请参阅参考资料)。然而,这里的欧几里德范数被使用,代替的最大范数。


(作者)----------Author(s)----------


Antonio, Fabio Di Narzo



参考文献----------References----------




实例----------Examples----------


res <- llar(log(lynx), m=3, neps=7)
plot(res)

x.new <- llar.predict(log(lynx),n.ahead=20, m=3, eps=1, onvoid="enlarge", r=5)
lag.plot(x.new, labels=FALSE)

x.fitted <-  llar.fitted(log(lynx), m=3, eps=1)
lag.plot(x.fitted, labels=FALSE)



转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。


注:
注1:为了方便大家学习,本文档为生物统计家园网机器人LoveR翻译而成,仅供个人R语言学习参考使用,生物统计家园保留版权。
注2:由于是机器人自动翻译,难免有不准确之处,使用时仔细对照中、英文内容进行反复理解,可以帮助R语言的学习。
注3:如遇到不准确之处,请在本贴的后面进行回帖,我们会逐渐进行修订。
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