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. 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 > > ?s 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 at ntu.edu.tw (S.T. Yen) [[alternative HTML version deleted]]
> On Oct 2, 2018, at 5:50 PM, Steven Yen <styen at 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 >> >> ?s 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 at ntu.edu.tw (S.T. Yen) > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.David Winsemius Alameda, CA, USA 'Any technology distinguishable from magic is insufficiently advanced.' -Gehm's Corollary to Clarke's Third Law
Thanks!!! It did wonders. Steven On 10/3/2018 9:39 AM, David Winsemius wrote:>> On Oct 2, 2018, at 5:50 PM, Steven Yen <styen at 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 >>> >>> ?s 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 at ntu.edu.tw (S.T. Yen) >> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. > David Winsemius > Alameda, CA, USA > > 'Any technology distinguishable from magic is insufficiently advanced.' -Gehm's Corollary to Clarke's Third Law > > > > > >-- styen at ntu.edu.tw (S.T. Yen) [[alternative HTML version deleted]]
David, Rui, and All: Greetings. 1. I need a helping hand with the polygon statement below so that I can have the area under the curve highlighted, between (z1,z2). 2. Is it possible to label the X-axis with in two scale, in the current z-scale and another, say x = (z+5)*2? Thank you. z1<- -1 z2<-? 2 curve(dnorm(x,0,1),xlim=c(-4,4),main="Standard Normal",xaxt="n",frame=F,xlab="z") jj<-seq(z1,z2,0.01) cord.x<-c(jj) cord.y<-c(dnorm(jj)) #polygon(cord.x,cord.y,col="skyblue") axis(1,at=c(-5,z1,0,z2,5),lab=c(-5,z1,0,z2,5)) abline(v=c(z1,z2)) -- styen at ntu.edu.tw (S.T. Yen) [[alternative HTML version deleted]]
I think this does what you want.
z1<- -1
z2<- 2
oldp <- par(mgp=c(3, .5, 0))
curve(dnorm(x,0,1), xlim=c(-5, 5),main="Standard Normal",
xaxt="n", frame=F, xlab="")
jj<-seq(z1,z2,0.01)
cord.x<- jj
cord.y<- dnorm(jj)
polygon(c(-1, cord.x, 2), c(0, cord.y, 0), col="skyblue")
axis(1,at=c(-5,z1,0,z2,5),lab=c(-5,z1,0,z2,5))
abline(v=c(z1,z2))
axis(1, at=c(-5, z1, 0, z2, 5), lab=(c(-5,z1,0,z2,5) + 5)*2, line=2)
par(oldp)
When you assign a vector to an object, you do not need to use c(), e.g. cord.x
<- jj. I expanded xlim= since you were labeling the axis at -5, and 5, but
only drawing the plot from -4 to 4.
To get the polygon to work, you need to add points to the baseline at at either
end.
The line= argument in axis() lets you put an axis line into the margin of the
plot. I used the mgp= argument in par() to close the space between the tickmarks
and their values.
--------------------------------------
David L. Carlson
Department of Anthropology
Texas A&M University
-----Original Message-----
From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Steven Yen
Sent: Sunday, October 21, 2018 1:47 PM
To: David Winsemius <dwinsemius at comcast.net>
Cc: r-help at r-project.org
Subject: Re: [R] Polygon
David, Rui, and All:
Greetings.
1. I need a helping hand with the polygon statement below so that I can
have the area under the curve highlighted, between (z1,z2).
2. Is it possible to label the X-axis with in two scale, in the current
z-scale and another, say x = (z+5)*2?
Thank you.
z1<- -1
z2<-? 2
curve(dnorm(x,0,1),xlim=c(-4,4),main="Standard
Normal",xaxt="n",frame=F,xlab="z")
jj<-seq(z1,z2,0.01)
cord.x<-c(jj)
cord.y<-c(dnorm(jj))
#polygon(cord.x,cord.y,col="skyblue")
axis(1,at=c(-5,z1,0,z2,5),lab=c(-5,z1,0,z2,5))
abline(v=c(z1,z2))
--
styen at ntu.edu.tw (S.T. Yen)
[[alternative HTML version deleted]]
______________________________________________
R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Yes, par(oldp) resets the parameter to its original value. The simplest way to get the area in this case would be to use pnorm():> pnorm(2) - pnorm(-1)[1] 0.8185946 If you have an arbitrary polygon, you can use polyarea() in the pracma package:> library(pracma) > polyarea(rev(c(-1, cord.x, 2)), rev(c(0, cord.y, 0)))[1] 0.8185917 The second differs slightly from the first because it is an approximation based on 101 points (the default for the curve() function). The polyarea() function wants the polygon to be defined counter-clockwise so we use rev() to reverse the coordinates. Without this you will get a negative area, but you can always use abs() to fix that:> polyarea(c(-1, cord.x, 2), c(0, cord.y, 0))[1] -0.8185917> abs(polyarea(c(-1, cord.x, 2), c(0, cord.y, 0)))[1] 0.8185917 One more point. Don?t use abbreviations for TRUE and FALSE (e.g. frame=F). FALSE cannot be redefined, but F can be. If you used a variable called F in earlier code, it could change the behavior of curve():> curve(dnorm(x,0,1), xlim=c(-5, 5), frame=F) > FALSE <- 1Error in FALSE <- 1 : invalid (do_set) left-hand side to assignment> F <- 1 > curve(dnorm(x,0,1), xlim=c(-5, 5), frame=F)---------------------------------------- David L Carlson Department of Anthropology Texas A&M University College Station, TX 77843-4352 From: Steven Yen <styen at ntu.edu.tw> Sent: Sunday, October 21, 2018 9:54 PM To: David L Carlson <dcarlson at tamu.edu> Subject: Re: [R] Polygon Thank you David. This is great!! I can follow all you do, except one. What does the last statement do: par(oldp). I would think that it reset the parameters, needed only if there is a next job. I am a little embarrassed to push this further, but let me see if I can bounce another thing out of this. Is it possible to have a "call-out", somehow indicating that the probability associated witht he shaded area is, say, 0.45. Is this possible? Am I asking too much of R? Fine if not. Thanks again!!! On 10/22/2018 4:24 AM, David L Carlson wrote: I think this does what you want. z1<- -1 z2<- 2 oldp <- par(mgp=c(3, .5, 0)) curve(dnorm(x,0,1), xlim=c(-5, 5),main="Standard Normal", xaxt="n", frame=F, xlab="") jj<-seq(z1,z2,0.01) cord.x<- jj cord.y<- dnorm(jj) polygon(c(-1, cord.x, 2), c(0, cord.y, 0), col="skyblue") axis(1,at=c(-5,z1,0,z2,5),lab=c(-5,z1,0,z2,5)) abline(v=c(z1,z2)) axis(1, at=c(-5, z1, 0, z2, 5), lab=(c(-5,z1,0,z2,5) + 5)*2, line=2) par(oldp) When you assign a vector to an object, you do not need to use c(), e.g. cord.x <- jj. I expanded xlim= since you were labeling the axis at -5, and 5, but only drawing the plot from -4 to 4. To get the polygon to work, you need to add points to the baseline at at either end. The line= argument in axis() lets you put an axis line into the margin of the plot. I used the mgp= argument in par() to close the space between the tickmarks and their values. -------------------------------------- David L. Carlson Department of Anthropology Texas A&M University -----Original Message----- From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Steven Yen Sent: Sunday, October 21, 2018 1:47 PM To: David Winsemius mailto:dwinsemius at comcast.net Cc: mailto:r-help at r-project.org Subject: Re: [R] Polygon David, Rui, and All: Greetings. 1. I need a helping hand with the polygon statement below so that I can have the area under the curve highlighted, between (z1,z2). 2. Is it possible to label the X-axis with in two scale, in the current z-scale and another, say x = (z+5)*2? Thank you. z1<- -1 z2<-? 2 curve(dnorm(x,0,1),xlim=c(-4,4),main="Standard Normal",xaxt="n",frame=F,xlab="z") jj<-seq(z1,z2,0.01) cord.x<-c(jj) cord.y<-c(dnorm(jj)) #polygon(cord.x,cord.y,col="skyblue") axis(1,at=c(-5,z1,0,z2,5),lab=c(-5,z1,0,z2,5)) abline(v=c(z1,z2)) -- mailto:styen at ntu.edu.tw (S.T. Yen)
Putting it all together:
z1<- -1
z2<- 2
oldp <- par(mgp=c(3, .5, 0))
curve(dnorm(x,0,1), xlim=c(-5, 5),main="Standard Normal",
xaxt="n", frame=F, xlab="")
jj<-seq(z1,z2,0.01)
cord.x<- jj
cord.y<- dnorm(jj)
polygon(c(-1, cord.x, 2), c(0, cord.y, 0), col="skyblue")
axis(1,at=c(-5,z1,0,z2,5),lab=c(-5,z1,0,z2,5))
abline(v=c(z1,z2))
axis(1, at=c(-5, z1, 0, z2, 5), lab=(c(-5,z1,0,z2,5) + 5)*2, line=2)
segments(.5, .1, 3, .2, lwd=2)
lbl <- paste0("Area = ", round(pnorm(2) - pnorm(-1), 4))
text(3, .2, lbl, pos=4, offset=.25)
par(oldp)
----------------------------------------
David L Carlson
Department of Anthropology
Texas A&M University
College Station, TX 77843-4352
From: Steven Yen <styen at ntu.edu.tw>
Sent: Monday, October 22, 2018 11:53 AM
To: David L Carlson <dcarlson at tamu.edu>
Subject: Re: [R] Polygon
Thanks David. I do know what to do with pnorm.
By call-out I was hoping to get indication/annotation of probability like the
attached.
Maybe I am asking too much of the data, as I suspect R is not meant to do that.
I appreciate your help. I am just trying to make these graphs for stat teaching
without graphic software like correl draw.
On 10/22/2018 9:34 PM, David L Carlson wrote:
Yes, par(oldp) resets the parameter to its original value.
The simplest way to get the area in this case would be to use pnorm():
pnorm(2) - pnorm(-1)
[1] 0.8185946
If you have an arbitrary polygon, you can use polyarea() in the pracma package:
library(pracma)
polyarea(rev(c(-1, cord.x, 2)), rev(c(0, cord.y, 0)))
[1] 0.8185917
The second differs slightly from the first because it is an approximation based
on 101 points (the default for the curve() function). The polyarea() function
wants the polygon to be defined counter-clockwise so we use rev() to reverse the
coordinates. Without this you will get a negative area, but you can always use
abs() to fix that:
polyarea(c(-1, cord.x, 2), c(0, cord.y, 0))
[1] -0.8185917
abs(polyarea(c(-1, cord.x, 2), c(0, cord.y, 0)))
[1] 0.8185917
One more point. Don?t use abbreviations for TRUE and FALSE (e.g. frame=F). FALSE
cannot be redefined, but F can be. If you used a variable called F in earlier
code, it could change the behavior of curve():
curve(dnorm(x,0,1), xlim=c(-5, 5), frame=F)
FALSE <- 1
Error in FALSE <- 1 : invalid (do_set) left-hand side to assignment
F <- 1
curve(dnorm(x,0,1), xlim=c(-5, 5), frame=F)
----------------------------------------
David L Carlson
Department of Anthropology
Texas A&M University
College Station, TX 77843-4352
From: Steven Yen mailto:styen at ntu.edu.tw
Sent: Sunday, October 21, 2018 9:54 PM
To: David L Carlson mailto:dcarlson at tamu.edu
Subject: Re: [R] Polygon
Thank you David. This is great!!
I can follow all you do, except one. What does the last statement do: par(oldp).
I would think that it reset the parameters, needed only if there is a next job.
I am a little embarrassed to push this further, but let me see if I can bounce
another thing out of this.
Is it possible to have a "call-out", somehow indicating that the
probability associated witht he shaded area is, say, 0.45. Is this possible? Am
I asking too much of R? Fine if not. Thanks again!!!
On 10/22/2018 4:24 AM, David L Carlson wrote:
I think this does what you want.
z1<- -1
z2<- 2
oldp <- par(mgp=c(3, .5, 0))
curve(dnorm(x,0,1), xlim=c(-5, 5),main="Standard Normal",
xaxt="n", frame=F, xlab="")
jj<-seq(z1,z2,0.01)
cord.x<- jj
cord.y<- dnorm(jj)
polygon(c(-1, cord.x, 2), c(0, cord.y, 0), col="skyblue")
axis(1,at=c(-5,z1,0,z2,5),lab=c(-5,z1,0,z2,5))
abline(v=c(z1,z2))
axis(1, at=c(-5, z1, 0, z2, 5), lab=(c(-5,z1,0,z2,5) + 5)*2, line=2)
par(oldp)
When you assign a vector to an object, you do not need to use c(), e.g. cord.x
<- jj. I expanded xlim= since you were labeling the axis at -5, and 5, but
only drawing the plot from -4 to 4.
To get the polygon to work, you need to add points to the baseline at at either
end.
The line= argument in axis() lets you put an axis line into the margin of the
plot. I used the mgp= argument in par() to close the space between the tickmarks
and their values.
--------------------------------------
David L. Carlson
Department of Anthropology
Texas A&M University
-----Original Message-----
From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Steven Yen
Sent: Sunday, October 21, 2018 1:47 PM
To: David Winsemius mailto:dwinsemius at comcast.net
Cc: mailto:r-help at r-project.org
Subject: Re: [R] Polygon
David, Rui, and All:
Greetings.
1. I need a helping hand with the polygon statement below so that I can
have the area under the curve highlighted, between (z1,z2).
2. Is it possible to label the X-axis with in two scale, in the current
z-scale and another, say x = (z+5)*2?
Thank you.
z1<- -1
z2<-? 2
curve(dnorm(x,0,1),xlim=c(-4,4),main="Standard
Normal",xaxt="n",frame=F,xlab="z")
jj<-seq(z1,z2,0.01)
cord.x<-c(jj)
cord.y<-c(dnorm(jj))
#polygon(cord.x,cord.y,col="skyblue")
axis(1,at=c(-5,z1,0,z2,5),lab=c(-5,z1,0,z2,5))
abline(v=c(z1,z2))
--
mailto:styen at ntu.edu.tw (S.T. Yen)
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