双道环填充上次访问中丢失的AVAL记录

Question

我正在为一个数据集创建一个参数，对于每个结果(AVAL)都有一个特定的策略(复合策略2)。对于这一次访问，我需要对上次访问(DTYPE=LOV)中的AVAL进行估算(在这种情况下，早期终止，如果在该访问中存在AVAL，我需要将该AVAL用于先前缺少AVAL的访问。我的问题是，我如何做一个双道循环来实现这一点，并使缺失的AVAL记录在早期终止时就与AVAL一起填充，但不覆盖任何在AVAL存在的访问。下面是我当前数据集的片段和我想要的输出

input  PARAMCD $ STRATEGY :$30. DTYPE $ SUBJID $ VISIT :$30. AVAL :8.; 
infile datalines dlm = '|';
datalines;
TOTEDPS1|Composite strategy 2|LOV|1001|Week 2|61.2
TOTEDPS1|Composite strategy 2|LOV|1001|Week 4|
TOTEDPS1|Composite strategy 2|LOV|1001|Week 8|
TOTEDPS1|Composite strategy 2|LOV|1001|Week 12|
TOTEDPS1|Composite strategy 2|LOV|1001|Week 16|
TOTEDPS1|Composite strategy 2|LOV|1001|Early Termination|43.5
TOTEDPS1|Composite strategy 2|LOV|1002|Week 2|16
TOTEDPS1|Composite strategy 2|LOV|1002|Week 4|
TOTEDPS1|Composite strategy 2|LOV|1002|Week 8|
TOTEDPS1|Composite strategy 2|LOV|1002|Week 12|
TOTEDPS1|Composite strategy 2|LOV|1002|Week 16|
TOTEDPS1|Composite strategy 2|LOV|1002|Early Termination|6.6
;
run;

data want;
input  PARAMCD $ STRATEGY :$30. DTYPE $ SUBJID $ VISIT :$30. AVAL :8.; 
infile datalines dlm = '|';
datalines;
TOTEDPS1|Composite strategy 2|LOV|1001|Week 2|61.2
TOTEDPS1|Composite strategy 2|LOV|1001|Week 4|43.5
TOTEDPS1|Composite strategy 2|LOV|1001|Week 8|43.5
TOTEDPS1|Composite strategy 2|LOV|1001|Week 12|43.5
TOTEDPS1|Composite strategy 2|LOV|1001|Week 16|43.5
TOTEDPS1|Composite strategy 2|LOV|1001|Early Termination|43.5
TOTEDPS1|Composite strategy 2|LOV|1002|Week 2|16
TOTEDPS1|Composite strategy 2|LOV|1002|Week 4|6.6
TOTEDPS1|Composite strategy 2|LOV|1002|Week 8|6.6
TOTEDPS1|Composite strategy 2|LOV|1002|Week 12|6.6
TOTEDPS1|Composite strategy 2|LOV|1002|Week 16|6.6
TOTEDPS1|Composite strategy 2|LOV|1002|Early Termination|6.6
;
run;

Answer 1

对于任何有兴趣的人，我想出了一个解决办法

data want;
do _n_ = 1 by 1 until(last.usubjid);
  set have;
  by usubjid;
  if visit ='Early Termination' and not(missing(aval)) then last_non_missing = aval;
end;
do _n_ = 1 to _n_;
  set have;  
  aval =coalesce(aval,last_non_missing);
  output;
end;
drop last_non_missing;
run;