[julia-users] R's update(Update and Re-fit a Model) in Julia?

[Hongwei Liu]

Hi guys,

I am new to Julia and I have trouble in finding a similar function in Julia 
that has the ability of "update" in R.

For example, set formula = y ~ x1 + x2

In R, I can use update(formula, D  ~ . ) to change the formula from y ~ x1 
+ x2 to D ~ x1 + x2

In Julia, the formula's type is DataFrames.Formula and I have searched 
online and Dataframes document for a long time but still couldn't find the 
answer.

So my question is:

Is there are such a function in Julia? If not, is there a way to modify a 
formula directly?

Thanks a lot!!

Hongwei