在不同的图形ggplot2中保持相同的比例

Question

I want to create 3 graphs in ggplot2 as follows:

ggplot(observbest,aes(x=factor(iteration),y=bottles,colour=Team ,group=Team)) + geom_line() + scale_colour_gradientn(colours=rainbow(16)) 
ggplot(observmedium,aes(x=factor(iteration),y=bottles,colour=Team ,group=Team)) + geom_line() + scale_colour_gradientn(colours=rainbow(16))
ggplot(observweak,aes(x=factor(iteration),y=bottles,colour=Team ,group=Team)) + geom_line() + scale_colour_gradientn(colours=rainbow(16))

That is, three graphs displaying the same thing but for difference dataset each time. I want to compare between them, therefore I want their y axis to be fixed to the same scale with the same margins on all graphs, something the currently doesn't happen automatically.

Any suggestion?

Thanks

Answer 1

It sounds like a facet_wrap on all the observations, combined into a single dataframe, might be what you're looking for. Eg

library(plyr)
library(ggplot2)

observ <- rbind(
  mutate(observbest, category = "best"),
  mutate(observmedium, category = "medium"),
  mutate(observweak, category = "weak")
)

qplot(iteration, bottles, data = observ, geom = "line") + facet_wrap(~category)

Answer 2

Add + ylim(min_value,max_value) to each graph.

Another option would be to merge the three datasets with an id variable identifying which value is in which dataset, and then plot the three of them together, differentiating them by linetype for instance.

Answer 3

使用scale_y_continuous为每个图形定义y轴，并使它们都易于比较。