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标题: 问一base 题 [打印本页]

作者: shiyiming 时间: 2012-4-21 04:15
标题: 问一base 题
Which program does not contain an error?

proc report data=sasuser.houses nowd;
column style bedrooms baths;
define style / order;
define bedbathratio / computed format=4.2;
compute bedbathratio;
   bedbathratio=baths.sum/bedrooms.sum; endcomp;
run;

proc report data=sasuser.houses nowd;
column style bedrooms baths BedBathRatio;
define style / order;
define bedbathratio / order format=4.2;
compute bedbathratio;
   bedbathratio=baths.sum/bedrooms.sum; endcomp;
run;

proc report data=sasuser.houses nowd;
column style bedrooms baths BedBathRatio;
define style / order;
define bedbathratio / computed format=4.2;
compute bedbathratio;
   bedbathratio=baths.sum/bedrooms.sum; endcomp;
run;

proc report data=sasuser.houses nowd;
column style bedrooms baths BedBathRatio;
define style / order;
define bedbathratio / computed format=4.2;
compute bedbathratio;
   bedbathratio=baths/bedrooms;
endcomp;
run;

Correct answer: c

Program c correctly specifies a computed variable in the COLUMN statement, defines the variable in a DEFINE statement, and computes values using the form variable-name.statistic in a compute block.

求指教，另外几个选项错在那里

作者: shiyiming 时间: 2012-4-25 15:10
标题: Re: 问一base 题
column语句就列出所有变量，包括旧变量和新计算的变量，故A不对。
B中，define bedbathratio / order format=4.2; 因为要计算bedbathratio的值，故后面的选项就用computed，这和C比较便可看出。
D中，bedbathratio=baths/bedrooms;如果要在compute模块中用某变量计算新的变量，则要在要分析的旧变量之后加入一个统计符号，默认为.sum。
并不是什么求和的意思。对于变量如何计算，还要看具体的表达式。回答完毕！

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