SAS 转换和缺失数据

Question

我在 SAS 中使用 boxcox 转换和 proc transreg 过程，我想知道 SAS 如何处理丢失的数据。我有一个数据集，其中每个参与者每月一行，每个月都有一个连续变量。有几个月，这个变量不见了。 Box-Cox 变换的公式不使用变量的分布或其他任何东西。 SAS 是如何工作的，它是否排除了丢失的数据？

下面是我将 boxcox 转换应用于我的变量的代码：

PROC TRANSREG DATA=myfile DETAILS;
MODEL BOXCOX(myvariable/ parameter=0.1) = identity(month);
OUTPUT OUT= transformed_myfile;
RUN;

谢谢！

Answer 1

来自documentation：

PROC TRANSREG can estimate missing values, with or without category or monotonicity constraints, so that the regression model fit is optimized. Several approaches to missing data handling are provided. All observations with missing values in IDENTITY, CLASS, POINT, EPOINT, QPOINT, SMOOTH, PBSPLINE, PSPLINE, and BSPLINE variables are excluded from the analysis. When METHOD=UNIVARIATE (specified in the PROC TRANSREG or MODEL statement), observations with missing values in any of the independent variables are excluded from the analysis. When you specify the NOMISS a-option, observations with missing values in the other analysis variables are excluded. Otherwise, missing data are estimated, and the variable means are the initial estimates.

（强调）。您可以根据需要添加各种转换，或使用 SAS 的默认估计。

SAS 转换和缺失数据

SAS transformation and missing data

transformation

sas

normalization