[R] Arguments to "personalised" plot()

(Ted Harding) Ted.Harding at manchester.ac.uk
Mon Oct 8 01:10:48 CEST 2007


On 07-Oct-07 21:51:29, Rolf Turner wrote:
> 
> On 8/10/2007, at 10:01 AM, Deepayan Sarkar wrote:
>>[...]
>> I'm not sure exactly which part you didn't expect. Given this
>> definition of plotb, I would expect
>>
>> plotb(x,cos(x))
>>
>> to expand to
>>
>> plot(x, pch="+", col="blue", cos(x))
>>
>> and as far as I can tell, these give identical results.
>> Is that what surprises you? Why?
>>
>> The other possibility is that you are surprised by the behavior of
>>
>> plot(x, pch="+", col="blue", cos(x))
>>
>> Remember that named arguments trump positional matching, and
>> consequently, this is equivalent to
>>
>> plot(x, cos(x), pch="+", col="blue")
> 
> I think that this is the crucial issue.  I'm guessing that what  
> puzzled Ted (it is what certainly puzzled me) was ``how did
> plot() know that cos(x) was the y-value?''

Exactly!

> Your (very well expressed) explanation makes this clear.

Agreed!

>                       cheers,
> 
>                               Rolf Turner

And Cheers!
Ted.

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Date: 08-Oct-07                                       Time: 00:10:45
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