[R] Rotation of parallel lines

[Carl Witthoft]

See my answer at Stack Overflow -- repeated here for anyone else who wants a
trivial function.
# coordinate transform: cartesian plane rotation
xyrot<-function(pairs,ang){
	# pairs must be Nx2 matrix w/ x in first column and y in second
	xrot <- pairs[,1]*cos(ang) - pairs[,2]*sin(ang)
	yrot <- pairs[,1]*sin(ang) + pairs[,2]*cos(ang)
	return(invisible(cbind(xrot,yrot)))
}


tonio wrote
> Dear list, 
> 
> Consider these two parallel segments in a plot.
> 
> plot(c(1, 6), c(2, 2), type="n", xlim=c(0, 7), ylim=c(-2, 6))
> segments(1, 1, 6, 1)
> segments(1, 3, 6, 3)
> 
> 
> 
> How can I rotate the two lines together by a defined angle?
> 
> 
> Thank you all in advance.
> 
> Best,
> Antonio
> 
> 
> ________________________
> Antonio Rivero Ostoic
> Assistant professor, PhD
> 
> AARHUS UNIVERSITY
> School of Business and Social Science
> Quantitative Analytics Group and Cognition and Behaviour Lab
> Bartholins Allé 10 
> DK-8000 Aarhus C
> 
> T: +45 871 65421
> M: 

> jari@

>         
> 
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