根据特定条件使用sas表创建新变量

我有一个SAS表，它有一个数字变量

age

。我需要根据

age

的值构造新变量。新变量应具有以下逻辑：

---

• 如果0

  返回值在SAS宏中没有任何特殊意义。宏被称为“生成”代码，即宏调用被文本替换，文本是在处理宏处理器“理解”的内容后留下的（基本上，涉及以
  &
  或
  %
  开头的标记（单词））
  
  在您的例子中，宏处理器只是扩展宏变量（其余的只是文本，宏处理器保持不变），结果是：
  
  age0=if (age=>0) and (age<=25);
  then return 1;
  else return 0;
  age25=/*and so on*/
  
  或者，使其生成一个表达式，该表达式在执行时将计算为0或1（通过将结果直接赋给变量（布尔表达式的结果为1或0），或者使用更显式）：
  
  我同意尼古拉的观点，你应该退后一步，完全避免使用宏。您发布的示例代码似乎不正确，针对不同年龄段的四个条件仅分配给两个变量
  
  在SAS中，逻辑计算解析为1表示真，0表示假。此外，数字变量可以在逻辑表达式中使用，非零、非缺失值表示真或假
  
  因此，分配年龄范围标志变量的一系列代码如下：
  
  age0  =  0 < age <= 25 ;
  age25 = 25 < age <= 40 ;
  age40 = 40 < age <= 65 ;
  age65 = 65 < age <= 71 ;
  age71 = 71 < age ;
  
  取决于这个宏
  
  %macro make_flag_variables (var=, breakpoints=);
    %local I BREAKPOINT SUFFIX_LOW RANGE_LOW SUFFIX_HIGH RANGE_HIGH;
    %let I = 1;
    %do %while (%length(%scan(&breakpoints,&I,%str( ))));
      %let BREAKPOINT = %scan(&breakpoints,&I,%str( ));
  
      %let SUFFIX_LOW = &SUFFIX_HIGH;
      %let SUFFIX_HIGH = %sysfunc(TRANSLATE(&BREAKPOINT,_,.));
  
      %let RANGE_LOW = &RANGE_HIGH;
      %let RANGE_HIGH = &BREAKPOINT;
  
      %if &I > 1 %then %do;
          &VAR.&SUFFIX_LOW = &RANGE_LOW < &VAR <= &RANGE_HIGH; /* data step source code emitted here */
      %end; 
  
      %let I = %eval ( &I + 1 );
    %end;
  %mend;
  
  %宏生成标志变量（变量=，断点=）；
  %本地I断点后缀\低范围\低后缀\高范围\高；
  %设I=1；
  %执行%while（%length（%scan（&breakpoints，&I，%str（））；
  %让断点=%scan（&breakpoints，&I，%str（））；
  %让后缀_低=&后缀_高；
  %让后缀_HIGH=%sysfunc（转换（&断点，u…）；
  %让范围低=&范围高；
  %让范围_高=&断点；
  %如果&I>1%，则为%do；
  &变量和后缀低=&范围低<&变量是。表达式文档是一本有用的读物。“AND运算符”一节讨论了a%macro calc_age_interval(outvar, inputvar, lbound, ubound);
    if (&inputvar=>&lbound) and (&inputvar<=&ubound) then do;
      &outvar = 1;
    end; else do;
      &outvar = 0;
    end;
  %mend calc_age_interval;
  %calc_age_interval(outvar=age0, inputvar=age, lbound=0, ubound=25);
  
  %macro calc_age_interval(inputvar, lbound, ubound);
    ifn((&inputvar=>&lbound) and (&inputvar<=&ubound), 1, 0)
  %mend;
  age0 = %calc_age_interval(age, 0, 25); /* expands to age0=ifn(..., 1, 0); */
  
  if age < 0 then age_missing_or_negative = 1;
  else if age <= 25 then age0 = 1;
  else if age <= 40 then age25 = 1;
  ...
  
  age0  =  0 < age <= 25 ;
  age25 = 25 < age <= 40 ;
  age40 = 40 < age <= 65 ;
  age65 = 65 < age <= 71 ;
  age71 = 71 < age ;
  
  data have; age = 22; bmi = 20; run;
  options mprint;
  
  * easier to understand and not prone to copy paste issues or typos;
  data want;
    set have;
    %make_flag_variables (var=age, breakpoints=0 25 40 65 71)
    %make_flag_variables (var=bmi, breakpoints=0 18.5 25 30)
  run;
  
  %macro make_flag_variables (var=, breakpoints=);
    %local I BREAKPOINT SUFFIX_LOW RANGE_LOW SUFFIX_HIGH RANGE_HIGH;
    %let I = 1;
    %do %while (%length(%scan(&breakpoints,&I,%str( ))));
      %let BREAKPOINT = %scan(&breakpoints,&I,%str( ));
  
      %let SUFFIX_LOW = &SUFFIX_HIGH;
      %let SUFFIX_HIGH = %sysfunc(TRANSLATE(&BREAKPOINT,_,.));
  
      %let RANGE_LOW = &RANGE_HIGH;
      %let RANGE_HIGH = &BREAKPOINT;
  
      %if &I > 1 %then %do;
          &VAR.&SUFFIX_LOW = &RANGE_LOW < &VAR <= &RANGE_HIGH; /* data step source code emitted here */
      %end; 
  
      %let I = %eval ( &I + 1 );
    %end;
  %mend;
  
  92   data want;
  93     set have;
  94
  95     %make_flag_variables (var=age, breakpoints=0 25 40 65 71)
  MPRINT(MAKE_FLAG_VARIABLES):   age0 = 0 < age <= 25;
  MPRINT(MAKE_FLAG_VARIABLES):   age25 = 25 < age <= 40;
  MPRINT(MAKE_FLAG_VARIABLES):   age40 = 40 < age <= 65;
  MPRINT(MAKE_FLAG_VARIABLES):   age65 = 65 < age <= 71;
  96     %make_flag_variables (var=bmi, breakpoints=0 18.5 25 30)
  MPRINT(MAKE_FLAG_VARIABLES):   bmi0 = 0 < bmi <= 18.5;
  MPRINT(MAKE_FLAG_VARIABLES):   bmi18_5 = 18.5 < bmi <= 25;
  MPRINT(MAKE_FLAG_VARIABLES):   bmi25 = 25 < bmi <= 30;
  97   run;