Hi, for example:
today=rnorm(100) yesterday=rnorm(100) up=today[today>yesterday] down=today[today<yesterday] index.up=which(today>yesterday) index.down=which(today<yesterday) plot(up~yesterday[index.up],col="green",xlim=c(-5,5),ylim=c(-5,5)) points(down~yesterday[index.down],col="red") today: today's returns yesterday: yesterday's return up: returns if returns today are greater than yesterday down: return if returns are smaller than yesterday (for pairs of observations) index.up: index number of observations for which up==true index.down: index number of obersvations for which down=true plot: first plot today's returns against yesterday's returns for stocks that are up only (adjust plotting limits of x and y axis so as to accomodate the later plot of down stocks; plot ups in green) points: plot today's return against yesterday's returns for stocks that are down only (plot in the same plot generated above; plot in red) Cheers, Daniel ------------------------- cuncta stricte discussurus ------------------------- -----Ursprüngliche Nachricht----- Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von [EMAIL PROTECTED] Gesendet: Tuesday, November 25, 2008 12:35 PM An: r-help@r-project.org Betreff: [R] Line color based on data values? Hi all Does anyone know if it is possible when plotting a line or scatter plot, to selectively color the data points based on the data value? i.e. if plotting say the percentage change in stock price movements, to color +ve points in green and -ve points in red? And extending this to a user-defined range of colors based on the quartile of the data points? Thanks Rory Rory Winston RBS Global Banking & Markets 280 Bishopsgate, London, EC2M 4RB Office: +44 20 7085 4476 **************************************************************************** ******* The Royal Bank of Scotland plc. Registered in Scotland No 90312. Registered Office: 36 St Andrew Square, Edinburgh EH2 2YB. Authorised and regulated by the Financial Services Authority This e-mail message is confidential and for use by =\ th...{{dropped:10}} ______________________________________________ R-help@r-project.org mailing list 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.
