The variable must be numeric and has the initial value of zero. This statement adds the value of the expression to the variable while retaining the variable’s value from one iteration of the DATA step to the next。 下面两句和sum语句起到的效果一样 retain variable 0; variable = sum(variable...
set sashelp.class(keep = _numeric_); *只读入数值型变量; run; drop语句的用法和keep一样,套着用就行,另外drop=选项的效率也高于drop语句。 retain语句《不可执行的语句》retains values from the previous iteration of the DATA step 这个比较重要了,我先解释下sas的运行机制 sas的data步和run语句之间其实...
可执行语句会在DATA 步的各个迭代中执行某些操作;声明性语句则向SAS系统提供信息,并在系统编译程序语句时生效。 以下展示了一些在DATA步中用到的执行语句和声明性语句。 除了可执行(Executable)和声明性(Declarative)语句,SAS DATA step语句还可根据其...
Keep is the keyword and it acts as the SAS statement to write the variables that must be declared already on more than one dataset. It can be called in everywhere and anywhere of SAS datasets, without a keep statement means all the datasets are created under the data step that includes al...
DATA语句; INPUT语句; (用于DATA步的其它SAS语句) CARDS语句; [数据行] ; RUN; 例1就是直接用SAS语句从作业流中输入数据, 从而建立所需要的SAS数据集的一个例子。 Slide8卫生统计教研室彭斌 2.数据在外部文本文件中 从外部文本文件中读入数据来建立SAS数据集的一般形式为: ...
1.从raw data中生成一个SAS数据集。 data wghtclub; infile 'n:\handbook2\datasets\whtclub1.dat'; input idno team$starweight weightnow; run; 上面的代码中有几点需要注意的,第一,infile statement,这个语句指明了raw data数据存储的路径,类似于R中的setwd。当然了,与R中一样,存储路径是可以设定默认的,...
Numeric variables always have a length of 8 bytes in the program data vector and during processing. 就是说length语句不会影响读入数据的长度,对于读入数据,原始长度是多少读进去就是多少 keep in mind that the LENGTH statement affects the length of a numeric variable only in the output data set. ...
B. The data set is created when the view TEMP is used in another SAS step. 4、函数coalesce()返回列表中第一个非null表达式的值。如果所有表达式求值为null,则返回null 。(63.11) 5、FILEVAR选项(63.21) 6、内连接外连接(63.26、37、46)
SAS_Adv最强机经
Consider the following data step: data WORK.TEST; set SASHELP.CLASS(obs=5); retain City 'Beverly Hills'; State='California'; run; The computed variables City and State have their values assigned using two different methods, a RETAIN statement and an Assignment statement. Which statement regardi...