ggplot2: Create an independent copy from an ggplot-Object
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I'm not sure how to put this in OO-Speech. But when you are creating a ggplot it will be dependent from the source data.frame. So how can you save a ggplot without that dependency?

    dat <- data.frame(x=runif(10),y=runif(10))  
    g <- ggplot(dat, aes(x,y)) + geom_point()  
    g  
       
    dat <- NULL  
    g

The second $g$ won't produce a plot hence dat is $NULL$. How can I save $g$ so that dat can be changed?

I know it is not good practice but I got some very long code on which I don't want to fiddle about.