michellang at gmail.com
2006-Jun-23 13:55 UTC
[Rd] symbols() draws squares too high (PR#9027)
Full_Name: Michel Lang Version: 2.2.1 OS: 2.6.16-gentoo-r9 on x86_64 Submission from: (NULL) (62.143.164.39) plot(-2:2, -2:2, type = "n") symbols(x = 0, y = 0, squares = 2, inches = FALSE, add = TRUE) This should plot a square with its center at (0,0) and side length 2, in other words a square from (-1,-1) as lower left angle to (1,1) as upper right angle. However, if you execute this line abline(h = c(-1,1)) you see that the squares height is definitely too large.
On 6/23/2006 9:55 AM, michellang at gmail.com wrote:> Full_Name: Michel Lang > Version: 2.2.1 > OS: 2.6.16-gentoo-r9 on x86_64 > Submission from: (NULL) (62.143.164.39) > > > plot(-2:2, -2:2, type = "n") > symbols(x = 0, y = 0, squares = 2, inches = FALSE, add = TRUE) > > This should plot a square with its center at (0,0) and side length 2, in other > words a square from (-1,-1) as lower left angle to (1,1) as upper right angle. > > However, if you execute this line > abline(h = c(-1,1)) > you see that the squares height is definitely too large.This is not a bug. The documentation says that when inches = FALSE, the units are those of the x axis, so horizontal lines are not relevant. Try abline(v=c(-1, 1)) If you want your x and y scales to be identical, I think you need to use grid and lattice, rather than traditional graphics, and to set aspect="iso". Duncan Murdoch