Moving Forward & Back in a Data Set

[JeffreyLowe]

I have a data set shown here in this screen shot. I need to move through the data set, skip to the even obs, grab the value in Rows, then move back to the previous obs and assign the Rows value I just picked to a column named Count.

So for the first, BpmnObject, move to next Obs (2) and grab Rows - 103 then move back previous Obs (1) and assign rows to Count

So my result set would look like:

RCT_Object_Type	Count
BpmnObject	3
Miscellaneos	2
Application	3216

[PhilC · Accepted solution]

Let's use SASHELP.CARS.  Here I'm assigning (incorrectly) the MSRP of the even observations to the odd observation above, outputting only the odd observations, after alteration.

data want;
  do i=1 to nob by 2; drop i;
    set SASHELP.CARS point=i nobs=nob; /*i is odd*/
    j=i+1; drop j;
    set SASHELP.CARS (keep=MSRP)  point=j ; /*j is even*/
    output;
  end;
  stop;
run;

[JeffreyLowe]

Thank you for the quick response! works like a charm! Really appreciate the help.

[Tom]

Much easier to carry values forward then moving them backwards.

data want;
  set have ;
  if mod(_n_,2)=1 then lagRCT_Object_Type=RCT_Object_Type;
  else output;
  retain lagRCT_Object_Type;
  keep lagRCT_Object_Type Count ;
run;

[JeffreyLowe]

Thank you Tom for the quick response! I really appreciate the help.