i have 2 datasets, data1, data2.as following
data data1;
input date : yymmdd10. exdate:yymmdd10. TTM ;
format date yymmdd10. exdate :yymmdd10. ;
datalines;
2004/1/2 2004/1/17 15
2004/1/2 2004/2/21 50
2004/1/2 2004/3/20 78
2004/1/5 2004/1/17 12
2004/1/5 2004/2/21 47
2004/1/5 2004/3/20 75
;
run;
data data2;
input date : yymmdd10. days rate ;
format date yymmdd10.;
datalines;
2004/1/2 19 1.11326
2004/1/2 47 1.156422
2004/1/2 75 1.178702
2004/1/5 16 1.108422
2004/1/5 44 1.154383
2004/1/5 72 1.170505
;
run;
i want to calculate the rate by linear Interpolation and linear Extrapolation as following.
data data3;
input date : yymmdd10. exdate:yymmdd10. TTM rate ;
format date yymmdd10. exdate :yymmdd10. ;
datalines;
date exdate TTM rate
2004/1/2 2004/1/17 15 1.107094
2004/1/2 2004/2/21 50 1.158809143
2004/1/2 2004/3/20 78 1.181089143
2004/1/5 2004/1/17 12 1.101856143
2004/1/5 2004/2/21 47 1.156110357
2004/1/5 2004/3/20 75 1.172232357
;
run;
please help me, thx