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R语言 SpatialVx包 metrV()函数中文帮助文档(中英文对照)

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发表于 2012-9-30 12:57:40 | 显示全部楼层 |阅读模式
metrV(SpatialVx)
metrV()所属R语言包:SpatialVx

                                         Calculate the binary location metric proposed in Zhu et al. (2011)
                                         计算Zhu等人提出的二进制文件的位置的度量。 (2011)

                                         译者:生物统计家园网 机器人LoveR

描述----------Description----------

Calculate the metric metrV proposed in Zhu et al (2011), which is a linear combination of the square root of the sum of squared error between two binary fields, and the mean error distance (Peli and Malah, 1982); or the difference in mean error distances between two forecast fields and the verificaiton field, if the comparison is performed between two forecast models against the same verification field.
计算的度量metrV Zhu等人(2011),这是两个二进制字段之间的平方误差的总和的平方根,平均误差距离(Peli和马拉,1982)的一个线性组合中提出;或差平均误差的两种预测领域和verificaiton的字段之间的距离,如果对相同的验证“字段中,两个预测模式之间进行比较。


用法----------Usage----------


metrV(object1, object2 = NULL, lam1 = 0.5, lam2 = 0.5, distfun = "distmapfun", verbose = FALSE, ...)



参数----------Arguments----------

参数:object1
list object as returned from the locmeasures2dPrep function.  
作为返回locmeasures2dPrep功能的列表对象。


参数:object2
(optional) list object returned from the locmeasures2dPrep function containing information for a second forecast model to be compared against the first forecast model (object1) against the same verification field, taken from object1.  
(可选)列表对象返回的locmeasures2dPrep函数的第二个预测模型进行比较,对相同的验证领域的第一个预测模型(object1),从object1包含的信息。


参数:lam1
numeric giving the weight to be applied to the square root of the sum of squared errors of binary fields term in metrV.  
数值给出的重量要施加到术语在metrV的二进制字段的平方误差的总和的平方根。


参数:lam2
numeric giving the weight to be applied to the mean error distance term in metrV.  
数字给予的权重被应用到的平均误差距离术语metrV。


参数:distfun
character naming a function with which to calculate the shortest distances between each point x in the grid and the set of events.  Default is the Euclidean distance metric (see the help file for locperf for more information).  
字符命名的函数,计算网格中的每个点x的事件集之间的最短距离。默认值是欧几里德距离度量(locperf更多信息,请参阅帮助文件)。


参数:verbose
logical, should progress information be printed ot the screen.  
逻辑,应该进步信息被打印ot的屏幕。


参数:...
Optional arguments to the distfun function.  
distfun功能的可选参数。


Details

详细信息----------Details----------

The binary location metric proposed in Zhu et al. (2011) is a linear combination of two measures: the amount of overlap between events in two fields, given by distOV (simply the square root of sum of squared errors between two binary fields), and (if there are events in both fields) the mean error distance described in Peli and Malah (1982); see also Baddeley (1992).  The metric can be computed between a forecast field, M1, and the verificaiton field, V, or it can be compared between two foreast models M1 and M2 with reference to V.  That is,
Zhu等人提出的二进制位置度量。 (2011)的线性组合的两个措施:在两个领域的事件之间的重叠量,给定者distOV(简单的两个二进制字段之间的平方误差的总和的平方根),和(如果有在这两个字段中的事件)平均误差距离Peli和马拉(1982),,巴德利(1992)。度量可以被计算之间的预测字段,M1,和verificaiton字段,V,或它可以比两个foreast模型M1和M2之间的参照五,即,

metrV(M1,M2) = lam1*distOV(I.M1,I.M2) + lam2*distDV(I.M1,I.M2),
metrV(M1,M2)= lam1 * distOV(I.M1,I.M2)+ lam2 * distDV(I.M1,I.M2),

where I.M1 (I.M2) is the binary field determined by M1 >= threshold (M2 >= threshold), distOV(I.M1,I.M2) = sqrt( sum( (I.M1 - I.M2)^2)), distDV(I.M1,I.M2) = abs(distob(I.V,I.M1) - distob(I.V,I.M2)), where distob(A,B) is the mean error distance between A and B, given by:
,在那里I.M1(I.M2)二进制字段由M1> =阈值(M2> =阈值)distOV的(I.M1,I.M2)= SQRT(SUM((I.M1  -  I. M2)^ 2)),distDV(I.M1,I.M2)= ABS(distob(IV,I.M1) -  distob(IV,I.M2),),,在那里distob(A,B)的平均误差A和B之间的距离,由下式给出:

e(A,B) = 1/(N(A))*sqrt( sum( d(x,B)), where the summation is over all the points x corresponding to events in A, and d(x,B) is the minimum of the shortest distance from the point x to each point in B.  e(A,B) is calculated by using the distance transform as calculated by the distmap function from package spatstat for computational efficiency.
E(A,B)= 1 /(N(A))* SQRT(SUM(D(X,B)),其中求和是对所有的点X对应中的事件,和D(X,B) B. E(A,B)中的每个点的点x的最短距离的最小值是通过使用所计算的距离变换从包装distmap函数计算spatstat为了计算效率。

Note that if there are no events in both fields, then by definition, the term distob(A,B) = 0, and if there are no events in one and only one of the two fields, then a large constant (here, the maximum dimension of the field), is returned.  In this way, distob differs from the mean error distance described in Peli and Malah (1982).
请注意,如果在这两个字段中没有任何事件,然后根据定义,术语distob(A,B)= 0,并且如果有一个且只有一个的两个字段中没有事件,那么一个大的常数(在这里,最大尺寸领域),被返回。以这种方式,distob不同于Peli和马拉(1982)中所述的距离的平均误差。

If comparing between the verification field and one forecast model, then the distDV term simplifies to just distob(I.V,I.M1).
如果比较验证字段和一个预测模型,然后distDV术语简化了到刚刚distob(IV,I.M1)。

One final note is that Eq (6) that defines distOV in Zhu et al. (2011) is correct (or rather, what is used in the paper).  It is not, as is stated below Eq (6) in Zhu et al. (2011) the root *mean* square error, but rather the root square error.  This is function computes Eq (6) as written.
最后要注意的是,式(6)定义distOV朱等人。 (2011年)是正确的(或者更确切地说,用的是什么纸)。实在不行,朱等人,则按公式(6)。 (2011)的根的意思*方的错误,而是平方根错误。这是一个函数计算式(6)作为写入。


值----------Value----------

list object of class "metrV" with components:
列表对象类“metrV”的组件:


参数:prep.obj1
character giving the name of the locmeasures2dPrep object as in the argument object1.
字符给locmeasures2dPrep在参数object1对象的名称。


参数:prep.obj2
If supplied, character giving the name of the locmeasures2dPrep object as in the argument object2.
如果提供,字符的名称locmeasures2dPrep对象的参数object2的。


参数:OvsM1
k X 3 matrix whose rows represent thresholds and columns give the component distOV, distob and metrV between the verification field and the forecast model 1.
K X 3矩阵的行表示阈值和列给组件distOV的,distob和metrV之间的的验证字段和预测模型1。


参数:OvsM2
If object2 supplied, k X 3 matrix whose rows represent thresholds and columns give the component distOV, distob and metrV between the verification field and the forecast model 2.
如果object2的提供的,K X 3矩阵的行表示阈值和列给组件distOV的,distob和metrV之间的的验证字段和预测模型2。


参数:M1vsM2
If object2 supplied, k X 3 matrix whose rows represent thresholds and columns give the component distOV, distob and metrV between model 1 and model 2.
如果object2的提供的,K X 3矩阵的行表示阈值和列给组件distOV的,distob和metrV,模式1和模式2之间。


(作者)----------Author(s)----------



Eric Gilleland




参考文献----------References----------





参见----------See Also----------

distob, distmap, im, solutionset, deltametric, locmeasures2d, locmeasures2dPrep
distob,distmap,im,solutionset,deltametric,locmeasures2d,locmeasures2dPrep


实例----------Examples----------


A <- B <- B2 <- matrix( 0, 10, 12)
A[2,3] <- 3
B[4,7] <- 400
B2[10,12] <- 17
hold <- locmeasures2dPrep("A", "B", thresholds=c(0.1,3.1,500))
metrV(hold)

hold2 <- locmeasures2dPrep("A", "B2", thresholds=c(0.1,3.1,500))
metrV( hold, hold2)

## Not run: [#不运行:]
data( pert000)
data(pert001)
testobj <- locmeasures2dPrep( "pert001", "pert000", thresholds=1e-8)
metrV( testobj) # compare to results in Fig. 3 (top right panel) of Zhu et al. (2011).[比较的结果图。 3(顶部右侧面板)Zhu等人。 (2011年)。]

data( geom000)
data( geom001)
testobj <- locmeasures2dPrep( "geom001", "geom000", thresholds=0)
metrV( testobj)
# compare above to results in Fig. 2 (top right panel) of Zhu et al. (2011).[比较上述中所示的结果。 2(顶部右侧面板)Zhu等人。 (2011年)。]
# Note that they differ wildly.  Perhaps because an actual elliptical area[需要注意的是它们之间的区别疯狂。也许是因为实际的椭圆形区域]
# is taken in the paper instead of finding the values from the fields themselves?[的文件,而不是找到自己的领域吗?]

## End(Not run)[#(不执行)]


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。
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