[R] Question about ggplot2 and stat_smooth

[Dennis Murphy]

Hi:

I would think that, at least in principle, this should work:

a <- ggplot(mtcars, aes(qsec, wt))
a + geom_point() + stat_smooth(fill="blue", colour="darkblue", size=2,
level = 0.9, alpha = 0.2) +
                   stat_smooth(fill = 'blue', colour = 'darkblue', size = 2,
                               level = 0.5, alpha = 0.4)

but geom_smooth() doesn't seem to react to different values of level.
I get the same bands on geom_smooth() if I use level = 0.95, 0.75 or
0.5. Since I make it a policy not to invoke the B word, I'll let
others who know more about the code comment on it.

BTW, ggplot2 related questions tend to get faster responses on its
list: ggplot2 at googlegroups.com. I've taken the liberty of forwarding
there since most of the developers read that list more regularly than
R-help.

Dennis

On Mon, Oct 3, 2011 at 10:24 AM, Thomas Adams <Thomas.Adams at noaa.gov> wrote:
>  I'm interested in creating a graphic -like- this:
>
> c <- ggplot(mtcars, aes(qsec, wt))
> c + geom_point() + stat_smooth(fill="blue", colour="darkblue", size=2, alpha
> = 0.2)
>
> but I need to show 2 sets of bands (with different shading) using 5%, 25%,
> 75%, 95% limits that I specify and where the heavy blue line is the median.
> I don't understand how to do this with ggplot2. What I am doing currently is
> to generate 'boxplots' (with 5%, 25%, 75%, 95% limits) at 6-hourly time
> steps (so I have a series of boxplots, which you can see by clicking on a
> map point:
> http://www.erh.noaa.gov/mmefs/index_test.php?Lat=38.2&Lon=-80.1&Zoom=5&Refresh=0&RFCOverlay=0&Model=NAEFS).
> Some who use our graphics would like to see something more like the ggplot2
> with stat_smooth graphic.
>
> Help is much appreciated.
>
> Regards,
> Tom
>
> --
> Thomas E Adams
> National Weather Service
> Ohio River Forecast Center
> 1901 South State Route 134
> Wilmington, OH 45177
>
> EMAIL:  thomas.adams at noaa.gov
>
> VOICE:  937-383-0528
> FAX:    937-383-0033
>
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