Whats going on here?
df<-data.frame(x=1:10,y=1:10)
ggplot()+geom_point(data=df,aes(x=x,y=y)) ## this is the normal usage
right?
ggplot()+geom_point(data=df,aes(x=df[,1],y=df[,2])) ## but I can also feed
it column indices
ggplot()+geom_point(aes(x=df[,'x'],y=df[,'y'])) ## or column names.
## but if i wrap it in a function...
plot.func.one<-function(dff,x.var,y.var){
print(ggplot() + geom_point(aes(x=dff[,x.var],y=dff[,y.var])))
}
plot.func.two<-function(dff,x.var,y.var){
print(ggplot() + geom_point(data=dff,aes(x=dff[,x.var],y=dff[,y.var])))
}
plot.func.three<-function(dff,x.var,y.var){
print(ggplot() + geom_point(data=dff,aes(x=eval(x.var),y=eval(y.var))))
}
plot.func.one(df,1,2) ## i assume the dff not found error is happening in
the aes call rather than the data= portion..
plot.func.one(df,'x','y') ## but why does it work in the global env and not
within a function?
plot.func.two(df,1,2)
plot.func.two(df,'x','y')
var.x<-'x'
var.y<-'y'
plot.func.three(df,var.x,var.y) ## why does it give the error on y.var
instead of x.var?
plot.func.three(df,'x','y')
dff<-df
x.var<-var.x
y.var<-var.y
plot.func.one(dff,x.var,y.var) ## now whats going on? I assume this works
because ggplot is looking globally rather than within the function...
plot.func.two(dff,x.var,y.var)
plot.func.three(dff,x.var,y.var)
nothing seems to work right! How do I plot within a function where I can
feed the function a data.frame and the columns I want plotted?
I assume this is some interesting name space issue but if you guys can
enlighten me as to what's going on...
Thanks,
Justin
P.S. So before I sent this I dug some more and found my answer, aes_string:
plot.func<-function(dff,x.var,y.var){
print(ggplot() + geom_point(data=dff,aes_string(x=x.var,y=y.var)))
}
plot.func(df,'x','y')
works great. But I still wouldn't mind some clarification on what's
happening in my earlier examples.
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