Thank you for your reply, removing : let it calculate the formula. I thought y and x could be replaced by column headings.
Now I am trying to plot it but have difficulties. Basically I want to do is what is done in R with the commandsgeom_smooth(method = "lm") and geom_smooth(method = "loess").
Following the example here
df = DataFrame(A = rand(500), B = repeat(1:10, inner=50), C = 1:500)
linear_model_df = lm(@formula(A ~ C),df)
pred = DataFrame(df(C)); #this does not work
pred.y = predict(model, pred)
Edit: I guess I am confused when to use x and y and when to use column headings.
Does one always need to state the intervals for the x axis?