RXridge(RXshrink)
RXridge()所属R语言包:RXshrink
Maximum Likelihood Shrinkage in Regression
在回归的最大似然收缩
译者:生物统计家园网 机器人LoveR
描述----------Description----------
Identify and display TRACEs for the Q-shaped shrinkage path, including the M-extent of shrinkage along that path, that are most likely under normal distribution theory to yield optimal reducions in MSE Risk.
识别和显示的Q型收缩路径的痕迹,其中包括M-程度的收缩沿着这条道路,是最有可能根据正态分布理论,以产生最佳的reducions在MSE风险。
用法----------Usage----------
RXridge(form, data, rscale = 1, Q = "qmse", steps = 8, nq = 21,
qmax = 5, qmin = -5, omdmin = 9.9e-13)
参数----------Arguments----------
参数:form
A regression formula [y~x1+x2+...] suitable for use with lm().
回归公式Y~X1 + X2 + ...]适合使用LM()。
参数:data
Data frame containing observations on all variables in the formula.
数据框包含公式中的所有变量的观察。
参数:rscale
One of three possible choices (0, 1 or 2) for rescaling of variables as they are being "centered" to remove non-essential ill-conditioning: 0 implies no rescaling; 1 implies divide each variable by its standard error; 2 implies rescale as in option 1 but re-express answers as in option 0.
三种可能的选择(0,1或2)的调整,也变量,因为他们正在“中心”,以消除非必要的病态:0意味着没有重新定标1表示将每个变量的标准错误;意味着重新调整选项1,但重新明确答案选项0。
参数:Q
Shape parameter that controls the curvature of the shrinkage path through regression-coefficient likelihood space (default = "qmse" implies use the value found most likely to be optimal.) Use Q = 0 to specify Hoerl-Kennard "ordinary" ridge regression.
形状参数,控制曲率的收缩路径,通过回归系数的可能性空间(默认值=“qmse”意味着使用最有可能成为最佳的价值。)使用Q = 0,以指定,肯纳德Hoerl“普通”脊回归。
参数:steps
Number of equally spaced values per unit change along the horizontal M-extent-of-shrinkage axis for estimates to be calculated and displayed in TRACES (default = 8.)
等距值单位变化的估计进行计算和显示的痕迹(默认值= 8 M-程度的收缩沿水平轴数)。
参数:nq
Number of equally spaced values on the lattice of all possible values for shrinkage Q-shape between the "qmin" and "qmax" parameter settings (default = 21.)
数量收缩的Q形“Qmin的”和“qmax个”参数设定(缺省值= 21之间的晶格上的所有可能值的相等间隔的值。)
参数:qmax
Maximum allowed Q-shape (default = +5.)
允许的最大Q-型(默认值= 5)。
参数:qmin
Minimum allowed Q-shape (default = -5.)
允许的最小Q-型(默认值= -5)。
参数:omdmin
Strictly positive minimum allowed value for one-minus-delta (default = 9.9e-013.)
严格为正一负增量(默认的最小允许值= 9.9E-013)。
Details
详细信息----------Details----------
Illconditioned and/or nearly multicollinear regression models are unlikely to produce Ordinary Least Squares (OLS) regression coefficient estimates that are very close, numerically, to their unknown true values. Specifically, OLS estimates can then tend to have "wrong" numerical signs and/or unreasable relative magnitudes, while shrunken (generalized ridge) estimates chosen to maximize their likelihood of reducing Mean Squared Error (MSE) Risk (expected loss) can be much more stable and reasonable, numerically. On the other hand, because only OLS estimates are quaranteed to be minimax when risk is matrix valued (truly multivariate), no guarantee of an actual reduction in MSE Risk is necessarily associated with shrinkage.
Illconditioned和/或近的多重共线性回归模型是不可能产生普通最小二乘法(OLS)回归系数估计值非常接近,数值模拟,对未知的真值。具体而言,OLS估计往往有“错误”的数字标志和/或unreasable的相对大小,而萎缩(广义岭)估计选择,以最大限度地降低风险(预期损失)的均方根误差(MSE)的可能性是多少更稳定,更合理的数值。另一方面,因为只有OLS估计是quaranteed的,是极大极小风险矩阵值(真正的多元),但不保证实际减少在MSE的风险是必然的联系与收缩。
值----------Value----------
An output list object of class RXridge:
输出列表对象类RXridge:
参数:form
The regression formula specified as the first argument.
作为第一个参数指定的回归公式。
参数:data
Name of the data.frame object specified as the second argument.
作为第二个参数指定的数据框对象的名称。
参数:p
Number of regression predictor variables.
数回归预测变量。
参数:n
Number of complete observations after removal of all missing values.
完整的观测搬迁后的所有缺失值数。
参数:r2
Numerical value of R-square goodness-of-fit statistic.
R-平方善良的拟合统计量的数值。
参数:s2
Numerical value of the residual mean square estimate of error.
剩余均方误差估计的数值。
参数:prinstat
Listing of principal statistics.
上市的主要统计数据。
参数:crlqstat
Listing of criteria for maximum likelihood selection of path Q-shape.
上市准则,选择最大似然路径Q的形状。
参数:qmse
Numerical value of Q-shape most likely to be optimal.
Q-形状的最有可能是最优的数值。
参数:qp
Numerical value of the Q-shape actually used for shrinkage.
实际使用的数值的Q-形收缩。
参数:coef
Matrix of shrinkage-ridge regression coefficient estimates.
收缩岭回归系数矩阵的估计。
参数:risk
Matrix of MSE risk estimates for fitted coefficients.
矩阵的的MSE风险估计拟合系数。
参数:exev
Matrix of excess MSE eigenvalues (ordinary least squares minus ridge.)
多余的MSE矩阵特征值(普通最小二乘法减去脊)。
参数:infd
Matrix of direction cosines for the estimated inferior direction, if any.
估计下方向的方向余弦矩阵,如果有的话。
参数:spat
Matrix of shrinkage pattern multiplicative delta factors.
矩阵的收缩模式乘法Delta因素。
参数:mlik
Listing of criteria for maximum likelihood selection of M-extent-of-shrinkage.
上市M-收缩程度最大似然选择的标准。
参数:sext
Listing of summary statistics for all M-extents-of-shrinkage.
上市的汇总统计所有M-程度的收缩。
(作者)----------Author(s)----------
Bob Obenchain <wizbob@att.net>
参考文献----------References----------
Ridge-type estimators for regression analysis. J. Roy. Stat. Soc. B 36, 284-291. (2-parameter shrinkage family.)
Biased Regression: The Case for Cautious Application. Technometrics 47, 284-296.
Shrinkage Regression: ridge, BLUP, Bayes, spline and Stein. Electronic book-in-progress (200+ pages.) http://members.iquest.net/~softrx/.
参见----------See Also----------
RXtrisk and RXtsimu.
RXtrisk和RXtsimu。
实例----------Examples----------
data(longley2)
form <- GNP~GNP.deflator+Unemployed+Armed.Forces+Population+Year+Employed
rxrobj <- RXridge(form, data=longley2)
rxrobj
names(rxrobj)
plot(rxrobj)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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