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标题: 找最大值! [打印本页]

作者: shiyiming 时间: 2010-8-8 21:12
标题: 找最大值!
请问各位前辈，sas有没有办法在同一群组中找出一个最大值呢，那其语法该怎么去写呢?请各位前辈帮帮忙!!
例:
群组数值 → 群组数值最大值
1 3 1 3 8
1 5 1 5 8
1 8 1 8 8
2 1 2 1 5
2 5 2 5 5
3 3 3 3 5
3 5 3 5 5
3 1 3 1 5
4 5 4 5 12
4 12 4 12 12
4 8 4 8 12

作者: shiyiming 时间: 2010-8-8 22:41
标题: Re: 找最大值!
[code:2ht29his]data raw;
      input group value;
datalines;
1 3
1 5
1 8
2 1
2 5
3 3
3 5
3 1
4 5
4 12
4 8
;
data out;
      do _n_=1 by 1 until(last.group);
            set raw;
            by group;
            max=max(value,max);
      end;
      do _n_=1 to _n_;
            set raw;
            output;
      end;
run;[/code:2ht29his]

作者: shiyiming 时间: 2010-8-9 01:36
标题: Re: 找最大值!
不好意思，那sas要如何设定group呢，其语法该怎么去写呢?请各位前辈帮帮忙!!
例:
date → data group
20010102 20010102 1
20010102 20010102 1
20010102 20010102 1
20010102 20010102 1
20010103 20010103 2
20010103 20010103 2
20010103 20010103 2
20010104 20010104 3
20010104 20010104 3
20010104 20010104 3
20010104 20010104 3

作者: shiyiming 时间: 2010-8-9 08:29
标题: Re: 找最大值!
[code:3myfj4yn]data raw;
input date yymmdd8. value;
format date yymmdd10.;
datalines;
20010102 3
20010102 5
20010102 8
20010102 1
20010103 5
20010103 3
20010103 5
20010104 1
20010104 5
20010104 12
20010104 8
;
data out;
do _n_=1 by 1 until(last.date);
set raw;
by date;
max=max(value,max);
end;
do _n_=1 to _n_;
set raw;
output;
end;
run;[/code:3myfj4yn]

作者: shiyiming 时间: 2010-8-9 14:48
标题: Re: 找最大值!
出现错误讯息，无法执行耶!

1 data raw;
2    input date yymmdd8. value;
3    format date yymmdd10.;
4 datalines;

NOTE: The data set WORK.RAW has 11 observations and 2 variables.
NOTE: DATA statement used (Total process time):
   real time          0.01 seconds
   cpu time          0.01 seconds

16 ;
17 data out;
18    do _n_=1 by 1 until(last.date);
19       set raw;
20       by date;
21       max=max(value,max);
22    end;
23    do _n_=1 to _n_;
24       set raw;
25       output;
26    end;
27 run;

ERROR: BY variables are not properly sorted on data set WORK.RAW.
last.date=0 date=2001-01-04 value=5 FIRST.date=1 max=1 _ERROR_=1 _N_=2
NOTE: The SAS System stopped processing this step because of errors.
NOTE: There were 10 observations read from the data set WORK.RAW.
NOTE: There were 7 observations read from the data set WORK.RAW.
WARNING: The data set WORK.OUT may be incomplete.  When this step was stopped there were 7 observations and 3 variables.
NOTE: DATA statement used (Total process time):
   real time          0.01 seconds
   cpu time          0.01 seconds

作者: shiyiming 时间: 2010-8-12 09:37
标题: Re: 找最大值!
data raw;
input date yymmdd8. value;
format date yymmdd10.;
datalines;
20010102 8
20010102 1
20010103 5
20010103 3
20010103 5
20010104 1
20010104 5
20010104 12
20010104 8
20010102 3
20010102 5
;
data ex1 ;
if _n_=1 then do;
   declare hash h(dataset:'raw', multidata: 'y',ordered:'n');
         h.defineKey('date');
         h.defineData('date', 'value');
         h.defineDone();
   /* avoid uninitialized variable notes */
   call missing(date,value);
end;

set raw;
      rc = h.find();
      if (rc = 0) then
            do;
                  max=value;
                  rc = h.find_next();
                  do while(rc = 0);
                        max=max(of max value);
                        rc = h.find_next();
                  end;
            end;
drop rc;
run;

data ex;
merge ex1 raw ;
run;
proc print;
run;

作者: shiyiming 时间: 2010-8-18 01:00
标题: Re: 找最大值!
[code:2eqzbbbk]data a;
input g x1-x3;
  cards;
20010102 3 1 3
20010102 5 1 5
20010102 8 1 8
20010103 1 2 1
20010103 5 2 5
20010104 3 3 3
20010104 5 3 5
20010104 1 3 1
20010105 5 4 5
20010105 12 4 12
20010105 8 4 8
;
run;
proc sql;
create table aa1(drop=x) as
  select *,max(x) as max_x
from (select *,max(x1,x2,x3) as x from a)
  group by g;
quit;[/code:2eqzbbbk]

I was confused by why you have to create a variable for group, actually you can treat '20010102,20010103, . . .' themselves as group variable.
And sorry if I misunderstood what you really want.

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