From: Ted Harding <Ted.Harding_at_nessie.mcc.ac.uk>

Date: Sat 02 Apr 2005 - 06:31:39 EST

for(i in (1:20)){if(x+i*dV<=U+2){lines(x+c(i,i)*dV,c(1.5,1.45))}} text(x+1/10,1.25,"Vernier",adj=0)

text(x+1/10,1.75,"Standard",adj=0)

text(0.25,0.75,

"1: Count the main divisions of Standard Scale for Units",adj=0)

text(0.25,0.60,

"2: Count the minor divisions of Standard Scale for Tenths",adj=0)

text(0.25,0.45,

"3: Count Vernier divisions till coincidence for Hundredths",adj=0)

}

E-Mail: (Ted Harding) <Ted.Harding@nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 094 0861

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Apr 02 07:56:29 2005

Date: Sat 02 Apr 2005 - 06:31:39 EST

Hi Folks,

I don't think I'm up to implementing a function for drawing French Curves, as requested by "dream".

However, the discussion about it took me back so vividly to the old days that, paranormally, I felt once again the urge to ascertain magnitudes as it used to be, and should be, done.

I have therefore implemented, and hereby donate to the R community, a new function vernier() which implements the Venier Caliper.

Its definition is below. Test it by entering

By following the instructions you should find that the result is

x = 3 Units + 5 Tenths + 7 Hundredths

All best wishes,

Ted.

vernier <- function(x,n=10) {

dS<-1/n; dV<-((n-1)/n)*dS

U<-floor(x)

plot(c(0,U+2,U+2,0,0),c(0,0,2,2,0),type="l",

main="Vernier Caliper",xlab="",ylab="",axes=FALSE) lines(c(0,U+2),c(1.5,1.5))

for(i in (0:(U+2))){lines(c(i,i),c(1.5,1.6))} for(i in (0:4)){lines(U+5*dS*c(i,i),c(1.5,1.575))} for(i in (0:20)){lines(U+dS*c(i,i),c(1.5,1.55))}lines(c(x,x),c(1.5,1.0))

for(i in (1:20)){if(x+i*dV<=U+2){lines(x+c(i,i)*dV,c(1.5,1.45))}} text(x+1/10,1.25,"Vernier",adj=0)

text(x+1/10,1.75,"Standard",adj=0)

arrows(0,1.25,x,1.25) arrows(x,1.25,0,1.25) text(x/2,1.15,"x")

text(0.25,0.75,

"1: Count the main divisions of Standard Scale for Units",adj=0)

text(0.25,0.60,

"2: Count the minor divisions of Standard Scale for Tenths",adj=0)

text(0.25,0.45,

"3: Count Vernier divisions till coincidence for Hundredths",adj=0)

}

E-Mail: (Ted Harding) <Ted.Harding@nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 094 0861

Date: 01-Apr-05 Time: 21:31:39 ------------------------------ XFMail ------------------------------ ______________________________________________R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Apr 02 07:56:29 2005

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