[R] Polygon

[David Winsemius]

> On Oct 2, 2018, at 5:50 PM, Steven Yen <styen using ntu.edu.tw> wrote:
> 
> Great. Thanks! It did wonders.
> 1. Is there a way to suppress the obvious tick stops (-3,-2,-1,0,1,2,3) 
> and mark only the ticks -1.96 and 1.96.
> 2. Better yet, to draw vertical lines at x = -1.96 and x = 1.96.
> Thanks.

Read ?plot.default

Then add xaxt="n" to the arguments to curve, ... and afterwards:

axis( 1, at=c(-1.96, 1.96),lab=c(-1.96, 1.96) )
abline( v= c(-1.96, 1.96) )

--
> Steven
> 
> On 10/3/2018 12:51 AM, Rui Barradas wrote:
>> Hello,
>> 
>> Continue with
>> 
>> 
>> polygon(-rev(cord.x), rev(cord.y), col = 'skyblue')
>> 
>> 
>> Hope this helps,
>> 
>> Rui Barradas
>> 
>> Às 17:25 de 02/10/2018, Steven Yen escreveu:
>>> Can someone help me with polygon. The following codes are self-runnable
>>> and mark a shaded area under the standard normal curve in the x-range
>>> (-3,-1).
>>> Is there a way to also mark the area in (1,3), at the same time.
>>> That is, I want shaded areas in both tails. Thank you...
>>> 
>>> ===
>>> # Create data for the area to shade
>>> cord.x <- c(-3,seq(-3,-1,0.01),-1)
>>> cord.y <- c(0,dnorm(seq(-3,-1,0.01)),0)
>>> 
>>> # Make a curve
>>> curve(dnorm(x,0,1), xlim=c(-3,3), main='Standard Normal')
>>> 
>>> # Add the shaded area.
>>> polygon(cord.x,cord.y,col='skyblue')
>>> 
>> 
> 
> -- 
> styen using ntu.edu.tw (S.T. Yen)
> 
> 
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> 
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David Winsemius
Alameda, CA, USA

'Any technology distinguishable from magic is insufficiently advanced.'   -Gehm's Corollary to Clarke's Third Law