similar to: Fancy pairs(), scatterplot matrix?

I have a math (and maybe an R) question. I want to find equilibrium population density values for a system of linear population growth equations (e.g., Pimm and Lawton 1977). The eventual goal is to perform stability analysis. I can find the partial differential equations for the Jacobian matrix, but I get stuck trying finding the equilibriuym pop densities (X*). Here is the (incorrect?) R code

Respected Sir, I am trying to import excel file into R, but I need to truncate some columns from the original file. How to delete unwanted columns when I import data from excel file. How to use cor.test for the data when I want the output rowwise. How to do grouping and use cor.test on that data I need some help regarding how to calculate the correlation. I don't know whether you

A search of the archives did not reveal an answer: For basic tests of association, where one has no a priori knowledge of the form of the relation or of the distributions of the variables, rank correlation seems like a good start. Why is cor.test() with Kendall and Spearman options relegated to the ctest package, rather than in the base package? Does this suggest that the developers consider

Hi All, I am running R 2.2.0 on Mac OS 10.4.2, dual G5 processors with 8 Gig RAM. I am running a simulation with lsoda that requires ~378 s to complete one set of time intervals. I need to optimize the parameters, and so need to considerably speed up the simulation. I have tried to figure out how to change the appropriate memory allocation and have search R help and Introductory

R 1.3.0, windows I've checked archives, and examples in text, mtext, and title. I am trying to include italicized text in the main title of a figure: ...., main = "[italics here] species name [italics stop] more plain text" TIA, Henry ***************************** Martin Henry H. Stevens HStevens at muohio.edu tel: (513) 529 - 4206 FAX: (513) 529 - 4243 338 Pearson Hall Botany

R v. 1.7.1, Windows 2000. A particular journal wants me to provide scatter plots with no box, but with axes that meet in the lower left corner. It seems as though there must be an easy way of doing this, but my reading the help on plot.default, axis, and box have not provided any clues. I would be most appreciative of any feedback. Thank you, Hank Stevens Dr. Martin Henry H. Stevens,

Using R v. 1.7.0 on Windows 2000 I would like to plot the fitted values of a model as a function of a continuous covariate, augmented with data (e.g., augPred) grouping by combinations of fixed effects. I have not been able to use augPred effectively, and am wondering if it does not handle unbalanced data (3 out of 192 missing). I include below the model and an xyplot that almost does the

Windows 2000, R 1.3.0 I have been given a data set (ASCII tab delimited) in which many variables that are supposed to be numeric actually contain characters. I would be happy to have those character entries disappear and become NA. When I use read.table and then attempt to convert these using as.numeric(), of course it doesn't work, and I get the ASCII? representation? maybe? When I use

(R 1.3.0, ESS, Emacs, Windows) I would like to import a set of objects exported from S+ v. 6, beta2 using data.dump, but I want to make sure that it does not overwrite current objects I am using in R. How would I route the output of data.restore() to ensure the safety of my current objects? Thanks very much, Henry ***************************** Martin Henry H. Stevens HStevens at muohio.edu tel:

Hi - I am getting different results when I run the numerical integrator function lsoda (odesolve package) on a Mac and a PC. I am trying to simulating a system of 10 ODE's with two exogenous pulsed inputs to the system, and have had reasonably good success with many model parameter sets. Under some parameter sets, however, the simulations fail on the Mac (see error message below). The

Hi Folks, I am using Windows 2000 and was wondering what (Open Source) software R users use or might recommend for symbolic computations (aside from the ol' noggin, e.g., Maxima, Mathomatic) . Thanks, Hank Dr. Martin Henry H. Stevens, Assistant Professor 338 Pearson Hall Botany Department Miami University Oxford, OH 45056 Office: (513) 529-4206 Lab: (513) 529-4262 FAX: (513) 529-4243

Windows 2000 (v.5.00.2195), R 1.5.1 I have an lme object, fm0, which I examine with anova() and intervals(). The anova output indicates one of the interaction terms is significant, but the intervals output shows that the single parameter for that term includes 0.0 in its 95% CI. I believe that the anova is a conditional (sequential) test; is intervals marginal or approximate? Which should I

All, In the function below I have 24 individuals and 6 calculations per individual. The 6 calculations are collected each time in a 1:24 loop when calculating "delta". I'd like to collect all 144 = 24*6 calculations in one vector ("delta.patient.comb"). The function works as is via indexing, but is there an easier way to collect the measurements via appendinng the 6

Hello all: I frequently have glm models in which the residual variance is much lower than the residual degrees of freedom (e.g. Res.Dev=30.5, Res.DF = 82). Is it appropriate for me to use a quasipoisson error distribution and test it with an F distribution? It seems to me that I could stand to gain a much-reduced standard error if I let the procedure estimate my dispersion factor (which

Windows 2000 . 5.00.2195 with Service Pack 1. R 1.5.1 Output from my split-split plot aov "alerted" me that I have done something wrong. I designed an experiment with all combinations of all levels of each treatment, but lost a little data (3 out of 192 plots). With the following data, I run the following model: > collim[c(1:6,187:192),c(1,3:6,9)] plot Litter Fert

Windows 2000, R 1.3.0 via ESS. It was my impression that example data sets could be accessed by simply typing in the name of the data set associated with any loaded library (e.g. 'cars', or if MASS is loaded, 'hills'). Why might this data not show up? Thanks for ideas in advance. ***************************** Martin Henry H. Stevens HStevens at muohio.edu tel: (513) 529 - 4206

I was trying to help someone who used a spanish keyboard on a PC running Windows. he discovered that he had no tilde key. Does anyone know of any simple work-arounds? Thanks, Hank Dr. Hank Stevens, Associate Professor 338 Pearson Hall Botany Department Miami University Oxford, OH 45056 Office: (513) 529-4206 Lab: (513) 529-4262 FAX: (513) 529-4243 http://www.cas.muohio.edu/~stevenmh/

Hi Folks, I was wondering what everyone thought about adding a sentence to each package update announcement that described what the package did. R extensions are so numerous that it is difficult to keep up with them. Would it be appropriate to ask package developers to add a brief sentence about what the package does, when they announce updates? I would benefit from such descriptions.

How do I control the text in strips? Specifically, I want to put in the ranges generated in shingle(x) where x is continuous. Thanks, Hank Martin Henry H. Stevens, Assistant Professor 338 Pearson Hall Botany Department Miami University Oxford, OH 45056 Office: (513) 529-4206 Lab: (513) 529-4262 FAX: (513) 529-4243 http://www.muohio.edu/~botcwis/bot/henry.html

Dear all: My logistic regression model includes one qualitative and one quantitative predictor variable, aes <- glm(p.a ~ spp * log(light), family=binomial(link=logit)), where spp is abundance of 3 species and light is subcanopy light availability varying from 0 1. I want to test differences among levels of the quantitative variable at a value of x other than the current log(light)=0.