SAS--do loop until while

　　

    data work.earning;       /*loop只发生在data步*/
        value=2000;
        do year=1 to 20;
        interest=value*0.075;
        value+interest;                       /*year=21*/
        end;
    run;
    proc print data=earning;
    run;

    /*升级版*/
    data work.earning(drop=counter);
        value=2000;
        do counter=1 to 20;
        interest=value*0.075;
        value+interest;
        year+1;                               /*year=20*/
        end;
    run;
    proc print data=earning;
    run;


data work.earning;
        value=2000;
        do year=1 to 20;
        interest=value*0.075;
        value+interest;
        output;   /*显示每一次执行的结果*/     /*year=1-20*/
        end;
    run;
    proc print data=earning;
    run;


    /*nesting 嵌套*/

    data earning;
        rate=0.0625/4;
        do year= 1 to 20;
            amount+2000;
            do quarter=1 to 4;
                amount+amount*rate;
                end;
        end;
    run;
    proc print data=earning;
    run;    


    data work.totals(drop=i balance /*记得drop i*/
     interest);
   set sasuser.loans;
   TotalInterest=0;              /*可有可无*/
   do i= 1 to months;    /*用变量来做循环时，循环里用到的变量一直使用当前值*/
      Interest=amount*(rate/12);
      amount+interest-payment;
      totalinterest+interest;
   end;
run;
proc print data=totals;
run;

/*每年投2000，年利率0.1，总额达到5万停手*/
  data work.invest;
        do until(Capital>=50000);  /*until至少执行一次*/
           capital+2000;
           capital+capital*.10;
           Year+1;
           output;
        end;
     run;

     data retire;
         saving=8000;
        income=42000;
        do until(saving>1000000);
            income+income*0.04;
            saving+income*0.1;
            year+1;
        end;
    run;

     data retire;
         saving=8000;
        income=42000;
        do while(saving<1000000);
            income+income*0.04;
            saving+income*0.1;
            year+1;
        end;
    run;

      data work.invest(drop=i);
        do i=1 to 30 until(Capital>=50000); /*两个循环条件，形成类似 |或门|   */
           Year+1;
           capital+2000;
           capital+capital*.10;
        end;
     run;

          data work.subset;
        do sample=10 to 5000 by 10;
           set factory.widgets point=sample;
           output;
        end;
        stop;
     run;