How to assign control as baseline values across all treatments?

[DelBS]

Hello,

I have run a factorial experiment with multiple levels of two factors. The first factor, Factor A, is the type of solute applied to my experimental units (7 levels). The second factor, Factor B, is the concentration of  solute applied to my experimental units (3 levels). I included a treatment without solute which provides a baseline measure of my response variable when the cocentration of solute applied is 0 grams / liter; it provides a fourth level for Factor B. How do I assign the control data as the '0' level data for Factor B across all of my levels for Factor A? I don't want to enter the data for my control treatment multiple times, since there was only one observation, however it applies to all of my levels of Factor A as level '0' of Factor B.

Factor A	Factor B (g/L)
Without solute (control)	0
Solute 1	1
Solute 2	1
Solute 3	1
Solute 4	1
Solute 5	1
Solute 6	1
Solute 7	1
Solute 1	5
Solute 2	5
Solute 3	5
Solute 4	5
Solute 5	5
Solute 6	5
Solute 7	5
Solute 1	10
Solute 2	10
Solute 3	10
Solute 4	10
Solute 5	10
Solute 6	10
Solute 7	10

Cheers,

Delaney.

[Shmuel]

You can assign the base line factor as a macro variable, out of all input data steps:

%let baseline_factor = 0;

So you do it once only. You can add it to the "sasinit" so don't nead to care at every input program.