R devel - Aug 2016 - problem with abine(lm(...)) for plot(y~x, log='xy')

Hello:


        In the following plot, the fitted line plots 100 percent above 
the points:


tstDat <- data.frame(x=10^(1:3), y=10^(1:3+.1*rnorm(3)))
tstFit <- lm(log(y)~log(x), tstDat)
plot(y~x, tstDat, log='xy')
abline(tstFit)


        I can get the correct line with the following:


tstPredDat <- data.frame(x=10^seq(1, 3, len=2))
tstPred <- predict(tstFit, tstPredDat)
lines(tstPredDat$x, exp(tstPred))


        I tried "abline(tstFit)" hoping it would work.  If the error
had
not been so obvious, I might not have noticed it.


        Thanks for your work to build a better R (and through that a 
better world).


        Spencer Graves

Try log10()...

-pd
> On 07 Aug 2016, at 21:03 , Spencer Graves <spencer.graves at
prodsyse.com> wrote:
> 
> Hello:
> 
> 
>       In the following plot, the fitted line plots 100 percent above the
points:
> 
> 
> tstDat <- data.frame(x=10^(1:3), y=10^(1:3+.1*rnorm(3)))
> tstFit <- lm(log(y)~log(x), tstDat)
> plot(y~x, tstDat, log='xy')
> abline(tstFit)
> 
> 
>       I can get the correct line with the following:
> 
> 
> tstPredDat <- data.frame(x=10^seq(1, 3, len=2))
> tstPred <- predict(tstFit, tstPredDat)
> lines(tstPredDat$x, exp(tstPred))
> 
> 
>       I tried "abline(tstFit)" hoping it would work.  If the
error had not been so obvious, I might not have noticed it.
> 
> 
>       Thanks for your work to build a better R (and through that a better
world).
> 
> 
>       Spencer Graves
> 
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com