ggplot2 - merge 2 plots (bubblechart, scatterplot) in R -

i new , new r hope provide sufficent information. have 2 kinds of datasets:

• 1 temperatures,dates (more rows other dataset);
• 1 buistemp,dates,bacteria , peilbuis.

i made 2 plots:

ggplot(data=data,aes(x=datum,y=temperatuur,size=bacteria,color=peilbuis)) +         geom_point() +         scale_size_continuous(range=c(2,10)) 

and

qplot(data=total,x=datum,y=temperatuur)+geom_line()

that give this: http://puu.sh/2ttju.png

however want create graph overlays these 2 plots. know how properly? (everytime try get: error: aesthetics must either length, and/or don't know how automatically pick scale object of type data.frame. defaulting continuous)

thank in advance.

try this:

ggplot(data=data,aes(x=datum,y=temperatuur,size=bacteria,color=peilbuis))+           geom_point()+           scale_size_continuous(range=c(2,10)) +           geom_line(data=total,aes(x=datum,y=temperatuur))