Dear Michael: Thank you very much.
I am still not able to make it works. thanks abou ======================== AbouEl-Makarim Aboueissa Sozan Elsalakawy Mohamed Agamia 246 Auburn Street, #158 Portland, ME 04103 USA Tel: (207) 797-2724 Email: [email protected] --- On Thu, 5/9/13, R. Michael Weylandt <[email protected]> wrote: From: R. Michael Weylandt <[email protected]> Subject: Re: [R-sig-teaching] graphing inequalities (intervals) in one varible To: "Yahoo!" <[email protected]> Cc: "R-sig-teaching" <[email protected]> Date: Thursday, May 9, 2013, 6:49 AM Here's the start of a function. I'll leave it to you to do it better (it should probably also use S4 methods, but that's another project): interval <- function(lower = -Inf, upper = Inf, lower_closed = FALSE, upper_closed = FALSE){ structure(.Data = NULL, lower = lower, upper = upper, lower_closed = lower_closed, upper_closed = upper_closed, class = 'interval') } plot.interval <- function(x){ l <- attr(x, "lower") u <- attr(x, "upper") r <- c(l, u) * c(if(l > 0) 0.7 else 1.2, if(u > 0) 1.2 else 0.7) plot(r, c(0,1), main = '', bty = 'n', xlab = '', ylab = '', yaxt = 'n', type = 'n', xaxt = 'n') axis(1, at = seq(r[1], r[2], length.out = 10)) lines(c(l, u), c(0.5, 0.5), col = 2, lwd = 2) lc <- attr(x, 'lower_closed') uc <- attr(x, 'upper_closed') points(c(l, u), c(0.5, 0.5), pch = c(1, 19)[c(lc, uc) + 1], col = 2, cex = 2) } On Wed, May 8, 2013 at 12:10 PM, Yahoo! <[email protected]> wrote: > Dear All: > > It seems a very silly question. But I never tried it before. I am teaching a > college algebra class this summer. > > I need some help with graphing intervals on the real line. For examples: > > {x | -7<= x < 5 and x > 7} > > {x | x > 3} > > etc... > > > thank you very much > abou > > ======================== > > AbouEl-Makarim Aboueissa > > Sozan Elsalakawy > > Mohamed Agamia > > > > 246 Auburn Street, #158 > > Portland, ME 04103 > > USA > > > > Tel: (207) 797-2724 > > Email: [email protected] > [[alternative HTML version deleted]] > > _______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-sig-teaching [[alternative HTML version deleted]]
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