sm.variogram(sm)
sm.variogram()所属R语言包：sm
A test of spatial independence based on smoothing an empirical variogram.
空间独立的基础上平滑的经验变差函数的测试。
译者：生物统计家园网 机器人LoveR
描述----------Description----------
This function constructs an empirical variogram, using the robust form of construction based on square-root absolute value differences of the data. Nonparametric regression is used to assess whether the mean value of the empirical variogram changes with distance. A hypothesis test and a graphical reference band are both available, under the assumption that the errors in the data are approximately normally distributed.
此功能构建了一个经验的变异函数，利用强大的建筑形式的基础上平方根绝对值差异的数据。非参数回归是用来评估是否平均值的经验变异函数随距离的变化。甲假设检验和一个图形化的参考频带都是可用的，根据数据中的错误的假设大致正态分布。
用法----------Usage----------
sm.variogram(x, y, h, ...)
参数----------Arguments----------
参数：x
a vector or two-column matrix of spatial location values.
的空间位置的值的矢量或两列的矩阵。
参数：y
a vector of responses observed at the spatial locations.
的空间位置时观察到的响应的向量。
参数：h
a smoothing parameter to be used on the distance scale. A normal kernel function is used and h is its standard deviation. However, if this argument is omitted h will be selected by an approximate degrees of freedom criterion, controlled by the df parameter. See sm.options for details.
距离刻度上的要使用的平滑参数。一个普通的内核函数的使用和h是标准差。但是，如果省略该参数，h将选择的一种近似程度的自由标准，df参数控制。见sm.options的详细信息。
参数：...
other optional parameters are passed to the sm.options function, through a mechanism which limits their effect only to this call of the function; those relevant for this function are add, eval.points, ngrid, se, xlab, ylab, xlim, ylim, lty; see the documentation of sm.options for their description. See the details section below for a discussion of the display and se parameters in this setting. </table>
其他可选的参数传递给sm.options功能，通过一种机制，限制了它们的作用仅此呼叫的功能，此功能相关的是add，eval.points，<X >，ngrid，se，xlab，ylab，xlim，ylim;他们看到的文档lty描述。请参阅下面的细节部分sm.options和display参数在此设置的讨论。 </ TABLE>
Details
详细信息----------Details----------
The reference below describes the statistical methods used in the function.
参考下面介绍的函数中使用的统计方法。
The display argument has a special meaning for this function. Its default value is "binned", which plots the binned version of the empirical variogram. As usual, the value "none" will suppress the graphical display. Any other value will lead to a plot of the individual differences between all observations. This will lead to a very large number of plotted points, unless the dataset is small.
display参数，此功能具有特殊的意义。它的默认值是"binned"，它描绘了分级的经验变差函数的版本。像往常一样，值"none"将抑制图形显示。其他任何值都将导致一个图的所有观测值之间的个体差异。这将导致一个非常大的数量的标绘点，除非该数据集是小。
Setting se = TRUE produces standard errors for the binned values of the empirical variogram. They are constructed to account for the correlation which arises from the differencing involved in the variogram. However, the calculations assume spatial independence and they therefore simply give an indication of the variability under this assumption.
设置se = TRUE分级的经验变差函数值的标准误差。他们建造的占参与的变差函数的差异而产生的相关。然而，计算假设空间的独立性，因此，他们干脆放弃这个假设的指示下的变异。
值----------Value----------
a list containing the raw (sqrtdiff, distance) and binned (sqrtdiff.mean, distance.mean) differences and distances, the frequencies of the bins (weights), the values of the estimate (estimate) at the evaluation points (eval.points) the value of the smoothing parameter (h) used, an indicator (ibin) of the bin in which the distance between each pair of observations was placed and the indices (ipair) of the original observations used to construct each pair. If a test of spatial independence has been performed, the p-value (p) is returned. If se was set to TRUE then the standard errors (se) of the binned values, under the assumption of spatial independence, are returned. If a reference band has been requested, the standard error (se.band) of the difference between the smooth estimate and the mean of all the data points is also returned.
一个列表，其中包含原始（sqrtdiff，distance）和分级（sqrtdiff.mean，distance.mean）的差异和距离，垃圾箱的频率（weights），在评价点（estimate）的值的平滑参数（eval.points）使用，指示器（h）的bin的值的估计（ibin）在每个观测对之间的距离被放置和使用的指数（ipair）原始观测构造每对。已被执行，如果测试的空间独立的p值（p）被返回。如果se设置为TRUE的标准误差（se）的分级值，空间独立的假设下，被返回。如果已被请求的参考带，标准误差（se.band）顺利预算和所有数据点的平均值之间的差异也被返回。
副作用----------Side Effects----------
a plot on the current graphical device is produced, unless the option display="none" is set.
对当前图形设备的图，，除非选项“display="none"设置。
参考文献----------References----------
Diblasi, A. and Bowman, A.W. (2001). On the use of the variogram for checking independence in a Gaussian spatial process. Biometrics, 57, 211-218.
参见----------See Also----------
sm.regression, sm.options
sm.regression，sm.options
实例----------Examples----------
provide.data(coalash)
Position <- cbind(East, North)
sm.options(df = 6)
par(mfrow=c(2,2))
sm.variogram(Position, Percent, band = FALSE)
sm.variogram(Position, Percent)
sm.variogram(East, Percent)
sm.variogram(North, Percent)
par(mfrow=c(1,1))
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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发表于 2012-9-30 10:47:40
