Re: [R] scatter plot & equation
Many thanks Duncan. I got the plot even I don't really understand the whole command.. I will study that later.. :-) Regards On Sun, Nov 22, 2009 at 4:44 PM, Duncan Murdoch wrote: > On 22/11/2009 11:27 AM, Rofizah Mohammad wrote: > >> Hi, >> >> If I have 2D data set say (x,y) and I can do scatter plot by using >> plot(x,y) >> command. >> How can I add in this scatter plot the equations curve say >> >> 2X2 + 3Y2 6X 7Y + 9 = 0. >> > > You could do it using contour(), but you should use an equation that has > some real solutions. For example, using a different equation than yours: > > x <- rnorm(100, sd=1) > y <- rnorm(100, sd=1) > xgrid <- seq(min(x), max(x), len=100) > ygrid <- seq(min(y), max(y), len=120) > grid <- expand.grid(x=xgrid, y=ygrid) > LHS <- function(x, y) x^2 + y^2 - x - y - 1 > z <- apply(grid, 1, function(x) LHS(x[1], x[2]) ) > z <- matrix(z, 100, 120) > plot(x,y) > contour(xgrid, ygrid, z, levels=0, add=TRUE) > [[alternative HTML version deleted]] __ 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.
Re: [R] scatter plot & equation
On Nov 22, 2009, at 11:27 AM, Rofizah Mohammad wrote: Hi, If I have 2D data set say (x,y) and I can do scatter plot by using plot(x,y) command. How can I add in this scatter plot the equations curve say 2X2 + 3Y2 6X 7Y + 9 = 0. No executable example... so if you are too lazy to construct one, then I would suggest looking for worked examples at one of the graphics galleries. Perhaps: http://addictedtor.free.fr/graphiques/RGraphGallery.php?graph=44 Regards Rofizah [[alternative HTML version deleted]] __ 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. David Winsemius, MD Heritage Laboratories West Hartford, CT __ 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.
Re: [R] scatter plot & equation
On 22/11/2009 11:27 AM, Rofizah Mohammad wrote: Hi, If I have 2D data set say (x,y) and I can do scatter plot by using plot(x,y) command. How can I add in this scatter plot the equations curve say 2X2 + 3Y2 – 6X – 7Y + 9 = 0. You could do it using contour(), but you should use an equation that has some real solutions. For example, using a different equation than yours: x <- rnorm(100, sd=1) y <- rnorm(100, sd=1) xgrid <- seq(min(x), max(x), len=100) ygrid <- seq(min(y), max(y), len=120) grid <- expand.grid(x=xgrid, y=ygrid) LHS <- function(x, y) x^2 + y^2 - x - y - 1 z <- apply(grid, 1, function(x) LHS(x[1], x[2]) ) z <- matrix(z, 100, 120) plot(x,y) contour(xgrid, ygrid, z, levels=0, add=TRUE) __ 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.
[R] scatter plot & equation
Hi, If I have 2D data set say (x,y) and I can do scatter plot by using plot(x,y) command. How can I add in this scatter plot the equations curve say 2X2 + 3Y2 6X 7Y + 9 = 0. Regards Rofizah [[alternative HTML version deleted]] __ 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.
