Re: [R] Problems with graphics
Thank you for your response, which is a partial solution to my problem. Actually, I would like to do the following plot. I have a data frame that includes the following variables: time, y=a response variable experimentally determined, ystd=its standard deviation, m=the modeled/simulated values for y, and F a classification/grouping variable. I would like to have a treillis plot, each panel corresponding to a level of F and includes y plotted against time with dots as symbol and with bars for standard deviation using ystd and m superimposed , plotted as a line. Thanks for your help, Chris Petr Pikal wrote: Hi Well, you did not specified what you have tried to do and how did you fail but On 2 Oct 2006 at 16:41, Christophe Nguyen wrote: Date sent:Mon, 02 Oct 2006 16:41:29 +0200 From: Christophe Nguyen [EMAIL PROTECTED] To: r-help@stat.math.ethz.ch Subject: [R] Problems with graphics Dear all, I am a SAS user, who's trying R. I am a little bit lost for graphics. What is the simplest way for plotting y as a function of x with one symbol (line or dot) for each level of a class variable z (for SAS If z is factor plot(x,y pch=as.numeric(z), ...) otherwise you need to change it to one. BTW, you can use the similar approach with lines and points - col, lwd, cex,... and othe parameters. langage= plot x*y=z). Can I add vertical bars for standard deviation there are various options, one is to use arrows with angle=90. arrows(x,y,x, y+ystd, angle=90) stored in a separate variable (say ystd). Finally, is it possible to do all this with xyplot function arranging plots according to A and B factor: xyplot(y~x|A*B) with as many plots and symbol as there is that is completely different story and you probably need to elaborate your own panel.function. HTH Petr levels in the z variable for each panel? Thanks for the help. Chris -- ___ Christophe NGUYEN UMR 1220 INRA-ENITAB Transfert sol-plante et cycle des éléments minéraux dans les écosystčmes cultivés Centre INRA de Bordeaux-Aquitaine 71, avenue Edouard Bourlaux, BP 81 33883 Villenave d'Ornon, FRANCE Tel : 00 33 (0)5 57 12 25 07 Fax : 00 33 (0)5 57 12 25 15 email : [EMAIL PROTECTED] page infoservice: http://www.bordeaux.inra.fr/tcem __m°O°m __ R-help@stat.math.ethz.ch 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. Petr Pikal [EMAIL PROTECTED] -- ___ Christophe NGUYEN UMR 1220 INRA-ENITAB Transfert sol-plante et cycle des éléments minéraux dans les écosystèmes cultivés Centre INRA de Bordeaux-Aquitaine 71, avenue Edouard Bourlaux, BP 81 33883 Villenave d'Ornon, FRANCE Tel : 00 33 (0)5 57 12 25 07 Fax : 00 33 (0)5 57 12 25 15 email : [EMAIL PROTECTED] page infoservice: http://www.bordeaux.inra.fr/tcem __m°O°m __ R-help@stat.math.ethz.ch 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] Problems with graphics
Dear all, I am a SAS user, who's trying R. I am a little bit lost for graphics. What is the simplest way for plotting y as a function of x with one symbol (line or dot) for each level of a class variable z (for SAS langage= plot x*y=z). Can I add vertical bars for standard deviation stored in a separate variable (say ystd). Finally, is it possible to do all this with xyplot function arranging plots according to A and B factor: xyplot(y~x|A*B) with as many plots and symbol as there is levels in the z variable for each panel? Thanks for the help. Chris -- ___ Christophe NGUYEN UMR 1220 INRA-ENITAB Transfert sol-plante et cycle des éléments minéraux dans les écosystèmes cultivés Centre INRA de Bordeaux-Aquitaine 71, avenue Edouard Bourlaux, BP 81 33883 Villenave d'Ornon, FRANCE Tel : 00 33 (0)5 57 12 25 07 Fax : 00 33 (0)5 57 12 25 15 email : [EMAIL PROTECTED] page infoservice: http://www.bordeaux.inra.fr/tcem __m°O°m __ R-help@stat.math.ethz.ch 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] PDE
Dear Ravi, Many thanks for your help. I guess the PDE I am interested in is parabolic: it is a diffusion+advection equation: dc/dt=D d2c/dx2 + vdc/dx Do you mean that I have to solve D d2c/dx2 + vdc/dx=0 for each time step, taking as initial condition at step n+1 the value of c at step n? Does the ODE package sollve second order differential equation? Best regards, Chris Ravi Varadhan wrote: Hi Christophe, What is the PDE that you are trying to solve? Is it parabolic/hyperbolic/elliptical/somethingelse? Is it linear/nonlinear? If time is one of the independent variables, you can transform the PDE into an initial value problem (system of ODEs) by using finite difference approximations of the partial derivatives of other independent variables (typically, these are spatial coordinates). Starting with an initial set of values on a grid of points (also known as initial conditions, which are part of the problem specification), you update them at different times, using fixed or varying time steps. R has very limited functionality for handling differential equations. So, you should look for FORTRAN libraries, from which you can create DLLs to be used in R. Hope this help, Ravi. --- Ravi Varadhan, Ph.D. Assistant Professor, The Center on Aging and Health Division of Geriatric Medicine and Gerontology Johns Hopkins University Ph: (410) 502-2619 Fax: (410) 614-9625 Email: [EMAIL PROTECTED] Webpage: http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Christophe Nguyen Sent: Wednesday, September 27, 2006 10:39 AM To: r-help@stat.math.ethz.ch Subject: [R] PDE Dear all, Does any know how to solve PDE with R? The archive list refers to the use of ODE if PDE are parabolic. I am not a mathematician and this does not mean anything for me! help would be very appreciated. Many thanks -- ___ Christophe NGUYEN UMR 1220 INRA-ENITAB Transfert sol-plante et cycle des éléments minéraux dans les écosystèmes cultivés Centre INRA de Bordeaux-Aquitaine 71, avenue Edouard Bourlaux, BP 81 33883 Villenave d'Ornon, FRANCE Tel : 00 33 (0)5 57 12 25 07 Fax : 00 33 (0)5 57 12 25 15 email : [EMAIL PROTECTED] page infoservice: http://www.bordeaux.inra.fr/tcem __m°O°m __ R-help@stat.math.ethz.ch 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] PDE
Dear all, Does any know how to solve PDE with R? The archive list refers to the use of ODE if PDE are parabolic. I am not a mathematician and this does not mean anything for me! help would be very appreciated. Many thanks -- ___ Christophe NGUYEN UMR 1220 INRA-ENITAB Transfert sol-plante et cycle des éléments minéraux dans les écosystèmes cultivés Centre INRA de Bordeaux-Aquitaine 71, avenue Edouard Bourlaux, BP 81 33883 Villenave d'Ornon, FRANCE Tel : 00 33 (0)5 57 12 25 07 Fax : 00 33 (0)5 57 12 25 15 email : [EMAIL PROTECTED] page infoservice: http://www.bordeaux.inra.fr/tcem __m°O°m __ R-help@stat.math.ethz.ch 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.
