Dear All,

Could you possibly help me on the following SAS programming problem?

From the original data set

data original; input a b c d e f: $CHAR1.; cards; 1 6 4 4 1 X 2 6 4 4 3 O 3 6 4 4 5 X 4 6 4 9 0 X 5 6 4 9 1 O

I want to create the new data set:

2 6 4 4 1 X 5 6 4 4 1 X 5 6 4 4 5 X 5 6 4 9 0 X

The new data set consists of the X (variable f) obs from the original data set that have been matched to the O obs (variable f) in the original data set according to certain rules (see below). Additionally, variable a of each of the X obs in the new data set reveals which O obs it’s been matched to.

What are the rules for matching X to O obs in the original data set? In order to match the X with the O obs,

1. the X obs must have an exact match in b and c with the O obs AND [2. the X obs must have either a smaller d value than the O obs OR 3. the X obs must have the same d value and a smaller e value than the O obs]

In the original data set, let’s take the first O obs, i.e. obs 2. Obs 1 satisfies conditions 1 and 3, the other X obs only satisfy condition 1 relative to obs 2, so obs 1 is the only X obs that’s matched to the first O obs, i.e. obs 2. It ends up in the new data set.

In the original data set, let’s take the other O obs. All X obs satisfy condition 1, obs 1 and 3 also satisfy condition 2, obs 4 also satisfies condition 3, so all three X obs are matched to obs 5 and end up in the new data set.

Please do let me know if something is unclear or if you need more information.

I greatly appreciate your help!

Best wishes,

Felix