fitspatgev(SpatialExtremes)
fitspatgev()所属R语言包:SpatialExtremes
MLE for a spatial GEV model
最大似然估计的空间GEV模型
译者:生物统计家园网 机器人LoveR
描述----------Description----------
This function derives the MLE of a spatial GEV model.
此功能派生的极大似然估计的空间GEV模型。
用法----------Usage----------
fitspatgev(data, covariables, loc.form, scale.form, shape.form,
temp.cov = NULL, temp.form.loc = NULL, temp.form.scale = NULL,
temp.form.shape = NULL, ..., start, control = list(maxit = 10000),
method = "Nelder", std.err.type = "score", warn = TRUE, corr = FALSE)
参数----------Arguments----------
参数:data
A matrix representing the data. Each column corresponds to one location.
矩阵表示数据。每一列对应于一个位置。
参数:covariables
Matrix with named columns giving required covariates for the GEV parameter models.
给予所需的的GEV参数模型的协变量的指定列的矩阵。
参数:loc.form, scale.form, shape.form
R formulas defining the spatial models for the GEV parameters. See section Details.
ŕ公式定义空间模型的GEV参数。请参见详细信息。
参数:temp.cov
Matrix with names columns giving additional *temporal* covariates for the GEV parameters. If NULL, no temporal trend are assume for the GEV parameters — see section Details.
矩阵的列名提供额外的时间*协变量的GEV参数的。如果NULL,没有时间趋势的假设的GEV参数 - 见章节详细信息“。
参数:temp.form.loc, temp.form.scale, temp.form.shape
R formulas defining the temporal trends for the GEV parameters. May be missing. See section Details.
ŕ公式定义的GEV参数的变化趋势。可能会丢失。请参见详细信息。
参数:start
A named list giving the initial values for the parameters over which the pairwise likelihood is to be minimized. If start is omitted the routine attempts to find good starting values - but might fail.
命名的列表,给出的参数成对的可能性是最小化的初始值。如果start省略的日常试图找到很好的起点值 - 但可能会失败。
参数:...
Several arguments to be passed to the optim functions. See section details.
几个参数被传递到optim功能。部分细节。
参数:control
The control argument to be passed to the optim function.
到传递给optim功能的控制参数。
参数:method
The method used for the numerical optimisation procedure. Must be one of BFGS, Nelder-Mead, CG, L-BFGS-B or SANN. See optim for details.
所使用的方法的数值优化程序。必须有一个BFGS,Nelder-Mead,CG,L-BFGS-B或SANN。见optim的详细信息。
参数:std.err.type
Character string. Must be one of "score", "grad" or "none". If none, no standard errors are computed.
字符的字符串。必须有一个“得分”,“研究生”或“无”。如果没有,没有标准的计算错误。
参数:warn
Logical. If TRUE (default), users will be warned if the starting values lie in a zero density region.
逻辑。如果TRUE(默认),用户将被警告说,如果初始值在于零密度区域。
参数:corr
Logical. If TRUE, the asymptotic correlation matrix is computed.
逻辑。如果TRUE,渐近相关矩阵的计算。
Details
详细信息----------Details----------
A kind of "spatial" GEV model can be defined by using response surfaces for the GEV parameters. For instance, the GEV location parameters are defined through the following equation:
可以定义一种“空间”GEV模型使用GEV参数的响应面。比如,GEV位置参数是通过下面的公式定义:
where X_μ is the design matrix and β_μ is the vector parameter to be estimated. The GEV scale and shape parameters are defined accordingly to the above equation.
X_μ是设计矩阵和β_μ的向量参数进行估计。 GEV规模和形状参数的相应定义的上述等式。
The log-likelihood for the GEV spatial model is consequently defined as follows:
为在GEV空间模型的对数似然因此定义如下:
where θ_i is the vector of the GEV parameters for the i-th site.
其中θ_i是i第网站的GEV参数矢量。
Most often, there will be some dependence between stations. However, it can be seen from the log-likelihood definition that we supposed that the stations are mutually independent. Consequently, to get reliable standard error estimates, these standard errors are estimated with their sandwich estimates.
大多数情况下,会有一些站之间的依赖。然而,可以看出,从对数似然的定义,我们假定站是相互独立的。因此,为了得到可靠的标准误差估计,这些标准的错误估计他们的三明治估计。
There are two different kind of covariates : "spatial" and "temporal".
有两种不同类型的协变量的“空间”和“时间”。
A "spatial" covariate may have different values accross station but does not depend on time. For example the coordinates of the stations are obviously "spatial". These "spatial" covariates should be used with the marg.cov and loc.form, scale.form, shape.form.
“空间”的协变量可能有不同的价值观,对面站,但不依赖于时间。例如站的坐标是明显的“空间”。这些“空间”的协变量,应使用与marg.cov和loc.form, scale.form, shape.form。
A "temporal" covariates may have different values accross time but does not depend on space. For example the years where the annual maxima were recorded is "temporal". These "temporal" covariates should be used with the temp.cov and temp.form.loc, temp.form.scale, temp.form.shape.
一个“时间”的协变量可能有不同的价值跨越时间,但不依赖于空间。例如,年的年度最大值记录的是“时间”。这些“时间”的协变量,应使用与temp.cov和temp.form.loc, temp.form.scale, temp.form.shape。
As a consequence note that marg.cov must have K rows (K being the number of sites) while temp.cov must have n rows (n being the number of observations).
因此说明这marg.cov必须有K行(K的网站数量),而temp.cov必须有n行(n为观测值的数量)。
值----------Value----------
An object of class spatgev. Namely, this is a list with the following arguments:
对象的类spatgev。也就是说,这是一个用下面的参数列表:
参数:fitted.values
The parameter estimates.
参数估计。
参数:param
All the parameters e.g. parameter estimates and fixed parameters.
所有的参数例如参数估计和固定的参数。
参数:std.err
The standard errors.
标准的错误。
参数:var.cov
The asymptotic MLE variance covariance matrix.
MLE的渐近方差协方差矩阵。
参数:counts,message,convergence
Some information about the optimization procedure.
的优化过程中的一些信息。
参数:logLik,deviance
The log-likelihood and deviance values.
对数似然值和偏差值。
参数:loc.form, scale.form, shape.form
The formulas defining the spatial models for the GEV parameters.
公式定义的空间模型,的GEV参数的。
参数:covariables
The covariables used for the spatial models.
的协变量用于空间模型。
参数:ihessian
The inverse of the Hessian matrix of the negative log-likelihood.
的负对数似然的Hessian矩阵的逆。
参数:jacobian
The variance covariance matrix of the score.
方差协方差矩阵的成绩。
(作者)----------Author(s)----------
Mathieu Ribatet
实例----------Examples----------
## 1- Simulate a max-stable random field[#1 - 模拟一个最大稳定的随机场]
n.site <- 35
locations <- matrix(runif(2*n.site, 0, 10), ncol = 2)
colnames(locations) <- c("lon", "lat")
data <- rmaxstab(50, locations, cov.mod = "whitmat", nugget = 0, range =
3, smooth = 0.5)
## 2- Transformation to non unit Frechet margins[#2 - 非单位的Frechet空间的转换]
param.loc <- -10 + 2 * locations[,2]
param.scale <- 5 + 2 * locations[,1]
param.shape <- rep(0.2, n.site)
for (i in 1:n.site)
data[,i] <- frech2gev(data[,i], param.loc[i], param.scale[i],
param.shape[i])
## 3- Fit a ''spatial GEV'' mdoel to data with the following models for[#3 - 装上一个“空的GEV”mdoel到以下车型]
## the GEV parameters[#GEV参数]
form.loc <- loc ~ lat
form.scale <- scale ~ lon
form.shape <- shape ~ 1
fitspatgev(data, locations, form.loc, form.scale, form.shape)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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