未排序数据上带有 BY 变量的 SAS 数据步骤

问题描述

我正在执行 SAS data step with by variable。当数据按键排序(在我的例子中为X)时,我理解输出。但是,当数据未排序时,我得到以下输出

SAS Output

我正在使用来自 AFRICA 库的 SAS ODAMAPS 数据集,它有 52824 行。 Here 是 CSV 文件链接

data  AFRICA_NEW12;
set Maps.AFRICA;
by X;
firstX = FirsT.X;
lastX = LAST.X;
run;

我不明白数据未排序时如何选择行。为什么输出有 14 行?

解决方法

您的日志中有错误,因为您没有对其进行排序。请务必阅读您的日志。

这可能会给您带来同样的问题:

data cars;
set sashelp.cars;
by model;
run;

proc print data=cars;
var make model origin;
run;

输出为:

Obs Make    Model   Origin
1   Acura   MDX Asia
2   Acura   RSX Type S 2dr  Asia

日志显示:

 ERROR: BY variables are not properly sorted on data set SASHELP.CARS.
 Make=Acura Model=TSX 4dr Type=Sedan Origin=Asia DriveTrain=Front MSRP=$26,990 Invoice=$24,647 EngineSize=2.4 Cylinders=4
 Horsepower=200 MPG_City=22 MPG_Highway=29 Weight=3230 Wheelbase=105 Length=183 FIRST.Model=1 LAST.Model=1 _ERROR_=1 _N_=3
 NOTE: The SAS System stopped processing this step because of errors.
 NOTE: There were 4 observations read from the data set SASHELP.CARS.
 WARNING: The data set WORK.CARS may be incomplete.  When this step was stopped there were 2 observations and 15 variables.
 WARNING: Data set WORK.CARS was not replaced because this step was stopped.

特别注意这部分:

警告:数据集 WORK.CARS 可能不完整。当这一步停止时,有 2 个观察值和 15 个变量。

如果您知道数据按您想要的顺序排序,这可能与 SAS 期望的不同,您可以添加 notsorted option on the BY statement 但这是一种不同类型的功能,因此请检查你的代码彻底。

data cars;
set sashelp.cars;
by model notsorted;
run;