zz: Change the variable value for consecutive variable with some special conditions

This question is answered by other people not me.

The data looks like below. Want to do: for the variable high, if there are consecutive 1s or consecutive -1s, we will compare the corresponding p_sm. For 1, keep the maximum p_sm and set the others as missing . ; for -1, keep the minimum and set the others as missing .;  For example, for the first and second obs with consecutive 1, since 102.88<105.29, we will change the second 1 as .;  In other words, We need to change 2, 14, 16, 20 and so on to be missing.

 

There are two methods given by elek:

    * method 1;

    data want;

            retain min max;

            do until (last.high);

                    set tmp1.have;

                    by high notsorted;

                    if first.high then do;

                            min=p_sm;

                            max=p_sm;

                   end;

                   else do;

                           min=min(min,p_sm);

                           max=max(max,p_sm);

                   end;

           end;

           do until (last.high);

                   set tmp1.have;

                   by high notsorted;

                   if high=1 and p_sm^=max then high=.;

                   if high=-1 and p_sm^=min then high=.;

                   output;

           end;

   run;

    * method 2;

    data tmp1;

            set tmp1.have;

            obs=_n_;

    run;

    proc means data=tmp1 noprint idmin;

            by high notsorted;

            var p_sm;

            id  p_sm obs;

           output out=tmp2(drop=_freq_ _type_) min(p_sm)=min max(p_sm)=max;

   run;

   proc means data=tmp1 noprint;

           by high notsorted;

           var p_sm;

           id  p_sm obs;

           output out=tmp3(drop=_freq_ _type_) min(p_sm)=min max(p_sm)=max;

   run;

   data want;

           merge tmp1 tmp2 tmp3;

           by obs;

           if high=1 and max^=p_sm then high=.;

           if high=-1 and min^=p_sm then high=.;

           drop min max obs;

   run;