Dear friends, I need to perform linear interpolations I do it correctly when I have only one dataset in one table However, I have many many different datasets in one table and each dataset should have its own interpolation curve Let's look at a simple example with only two datasets (A & B): NAME DEPTH X Y A 0,00 496323,56 6277756,14 0,50 , , 1,00 , , 1,50 , , 2,00 , , 2,50 , , 3,00 , , 3,50 , , 4,00 , , 4,50 , , 5,00 , , 5,50 , , 6,00 , , A 6,50 496210,94 6277828,15 7,00 , , 7,50 , , 8,00 , , 8,50 , , 9,00 , , 9,50 , , 10,00 , , 10,50 , , A 11,00 496210,87 6277828,25 B 0,00 516239.55347 6247816.3269 0.5 1,00 1,50 2,00 2,50 3,00 3,50 4,00 4,50 5,00 5,50 B 6,00 516239.55347 6247816.3269 6,50 7,00 7,50 8,00 8,50 B 9,00 516239.51534 6247816.3202 9,50 10,00 10,50 11,00 11,50 12,00 B 12,50 516239.47966 6247816.3124 I use the following proc procedure to perform linear regression for one dataset: proc expand data=&_INPUT1 out=&_OUTPUT1; convert X=linear_X / method=join; id DEPTH; run; proc expand data=&_INPUT1 out=&_OUTPUT1; convert Y=linear_Y / method=join; id DEPTH; run; The interpolation will fill the missing values for X and Y However, when I have two datasets (in this case A & B) or more I can't use this formula I know I need some kind of DO LOOP somewhere but I don't know where and how I should use it Can you please help me with it? Thank you vey much! Best regards Farshid
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