[R] model frame problem

Dear R community: I am working on a model frame problem which is important for my data analysis. What I am trying to get is to get data set d3 through the model formula "ff=y~a+b+a*b" and data set d1 to generate a new data set d3 which includes a interaction column between a and b rather than d2.

[R] model frame problem

Dear R community: I am working on a model frame problem which is important for my data analysis. What I am trying to get is to get data set d3 through the model formula "ff=y~a+b+a*b" and data set d1 to generate a new data set d3 rather than d2. I have tried several ways but did not get that done.