[R] add different regression lines for groups on ggplot

[Ye Lin]

Hey All,

I need to apply different regression lines to different group on my ggplot,
and here is the code I use:

qplot(x=Var1,y=Var2,data=df,color=SiteID,group=SiteID)+geom_point()+geom_smooth(method='lm',formula=log(y)~I(1/x),se=FALSE,size=2)

However the regression for different groups is as below:

AL1/AL2: log(y)~I(1/x)
AL3: log(y)~log(x)

How can I apply each regression equation on the same ggplot?

Also I have an issue that if I use the code above, the regression lines are
not overlapped on top of my data points.

Thanks for your help!