[R] ggplot2::qplot() -- arbitary transformations of coordinate system?

[Michael Kubovy]

Hi Stephen,

Because coord_trans() does all the work of plotting the original  
values on the tranformed scale. See ?coord_trans. To quote: "The  
difference between transforming the scales and transforming the  
coordinate system is that scale transformation occurs BEFORE  
statistics, and coordinate transformation afterwards."

# After
require(ggplot2)
data(diamonds)
# Three ways of doing transformating in ggplot:
# * by transforming the data
qplot(log10(carat), log10(price), data=diamonds)
# * by transforming the scales
qplot(carat, price, data=diamonds, log="xy")
qplot(carat, price, data=diamonds) + scale_x_log10() + scale_y_log10()
# * by transforming the coordinate system:
qplot(carat, price, data=diamonds) + coord_trans(x = "log10", y =  
"log10")

Michael

On Sep 5, 2009, at 9:01 PM, stephen sefick wrote:

> why not transform the y-data?
>
> On Sat, Sep 5, 2009 at 8:03 PM, Michael Kubovy<kubovy at virginia.edu>  
> wrote:
>> Hi,
>>
>> Does anyone know how to do a coord_trans() in which the y-axis is  
>> tranformed
>> into (for example) -1000/y?

> Stephen Sefick



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