朱世武的第二版《SAS编程技术教程》上有一个例子求变量CLPR的5日滑动平均线
data a;
set ResDat.Idx000001;
sum+clpr;
data b;
merge a a(firstobs=6 rename=(sum=sum_1));
ma5=(sum_1-sum)/5;
run;

为何我原样输入后却无法执行，提示信息如下，请教这是怎么回事呢：
1345  data a;
1346  set RESDAT.IDX000001;
NOTE: Data file RESDAT.IDX000001.DATA is in a format that is native to another host,
or the file   encoding does not match the session encoding. Cross Environment Data Access
will be used,
      which might require additional CPU resources and might reduce performance.
WARNING: Some character data was lost during transcoding in the dataset
RESDAT.IDX000001. Either   the data contains characters that are not representable in the new encoding
or truncation    occurred during transcoding.
1347  sum + clpr;
ERROR: Some character data was lost during transcoding in the dataset WORK.A. Either
the data    contains characters that are not representable in the new encoding or
truncation occurred   during transcoding.
NOTE: The SAS System stopped processing this step because of errors.
WARNING: The data set WORK.A may be incomplete.  When this step was stopped there
were 0   observations and 21 variables.
WARNING: Data set WORK.A was not replaced because this step was stopped.