@Jeg123 wrote:
I am trying to replace values using a script and for the first part I dont expect any changes, but SAS changes the values 'NaN' to '', which I dont understand why. Short example below
data test;
infile datalines delimiter=',';
input var $ row date $ group $;
datalines;
NaN,1,31OCT2016,-1-1d
NaN,2,31OCT2016,-1-1d
GCXK,3,30APR2017,-1-1d
;
DATA test2;
SET test;
BY group;
RETAIN new_var;
IF var NE 'NaN' then new_var = var;
IF var EQ 'NaN' then var = new_var;
IF last.var then new_var = 'NaN';
DROP new_var;
RUN;
Your code contains a mistake.
Maxim 2: read the log:
36 DATA test2;
37 SET test;
38 BY group;
39 RETAIN new_var;
40
41 IF var NE 'NaN' then new_var = var;
42 IF var EQ 'NaN' then var = new_var;
43
44 IF last.var then new_var = 'NaN';
45
46 DROP new_var;
47 RUN;
NOTE: Variable 'last.var'n is uninitialized.
NOTE: There were 3 observations read from the data set WORK.TEST.
NOTE: The data set WORK.TEST2 has 3 observations and 4 variables.
NOTE: DATA statement used (Total process time):
real time 0.01 seconds
cpu time 0.00 seconds
Just to get you on the right path: ask yourself: "from where does the first NOTE come from?"
About your question:
In obs #1, the first condition is FALSE, so new_var is not set.
The second condition is TRUE, so var is set to new_var (which is still missing, see above)
In obs #2, the same happens.
In obs #3, the first condition is TRUE, so new_var is set.
The second condition is FALSE, so var is not changed.
