similar to: substituting level for NA in factor column

Greetings Though I have months in chronological order in my data table, the data were sampled every other month (i.e., February, April, June, August, October, December), every time I try to plot them (on the x-axis) they are plotted in alphabetical order. What am I missing? Cheers Kurt *************************************************************** Kurt Lewis Helf, Ph.D. Ecologist EEO

Greetings Does anyone have any suggestions for reducing pdf file size, particularly pdfs containing photos, without sacrificing quality? Thanks for any tips in advance. Cheers Kurt *************************************************************** Kurt Lewis Helf, Ph.D. Ecologist EEO Counselor National Park Service Cumberland Piedmont Network P.O. Box 8 Mammoth Cave, KY 42259 Ph: 270-758-2163

Greetings Using the following command I've been trying to subset a dataframe of counts of an organism to compute the sizes of groups for use as a predictor: Hs.patches <- as.data.frame(with(Hs.long, table(Cave,Year,Month,Region,Plot,))) I am getting the following error message that I do not understand: ERROR: argument is missing, with no default Can anyone shed light on this

Greetings I want to remove numbers from a string of characters that identify sites so that I can merge two data frames. For example, a site in one frame is called "001a Frozen Niagara Entrance" whereas the same site in the other data frame is called "Frozen Niagara Entrance". It seems to me the easiest thing to do would be to remove the numbers from the first data

All Is there a script in R equivalent to the "if then" transforms one can perform in Systat? For example, I want to create a "Treatment" column coded either 1 or 2 for twelve field sites in a large data set. Ideally, I'd be able to tell R to code sites a-f as 1 and sites g-l as 2. Cheers Kurt *************************************************************** Kurt Lewis

Greetings I'm attempting to insert missing data on the smallest size class of cave cricket instars into a data frame. The data involve censusing photoplots (plots) of roosting cave crickets in which we discern in four instars or size classes. I need to insert data on size class one into a data frame that already has data on size classes two through four. The data can be merged by their

Greetings I am attempting to plot observations of a cave aquatic invertebrate dating from 1901-2004. I can come up with a nice lattice plot of the eight sites from which I have data easily enough. However, I'd like to be able to highlight the 0 observations on the plots, i.e., attempts to find it at the site were unsuccessful. I'd like to be able to highlight these observations

Greetings I'm having difficulty witht the strptime function. I can't seem to figure a way to strip month (name) and year and create separate columns from a column with MM/DD/YYYY formatted dates. Can anyone help? Cheers Kurt *************************************************************** Kurt Lewis Helf, Ph.D. Ecologist EEO Counselor National Park Service Cumberland Piedmont Network

Greetings How do I do this in R? Checking the Cran site produces a bewildering array of packages that I can't seem to find to load. Surely the main program has this function? Cheers Kurt *************************************************************** Kurt Lewis Helf, Ph.D. Invertebrate Ecologist National Park Service Cumberland Piedmont Network P.O. Box 8 Mammoth Cave, KY 42259 Ph:

Hi ? This is giving me a headache. I?m trying to do a relatively simple optimization ? actually trying to approximate the output from the Excel Solver function but at roughly 1000x the speed. ? The optimization parameters look like this. The only trouble is that I want to add a constraint that sum(wgt.vect)=1, and I can?t figure out how to do that in optim. Mo.vect <-

Hello, I have a question regarding subsetting of vectors. Here's an example of what I'm trying to do: vect.1 <- c(76,195, 290, 380) vect.2 <- c(63, 95, 133, 170, 215, 253, 285, 299, 325, 375) I would like to subset vect.2 so that it has the same length as vect.1, and its numbers are the first corresponging higher value compared to vect.1. The output should be: final.output =

Hi, I got caught out by this behaviour in 1.8.0 and I wondered why this happens: I have a list of vectors and was using lapply and grep to remove matched elements that occur in only a subset of the elements of the list: locs <- lapply(locs, function(x){x[- grep("^x", x)]}) The problem is that where the grep finds no matches and hence returns a vector of length 0, all the

Thanks Bert. But everyone on that forum wants to use finance tools rather than general optimization stuff! And I am not optimizing a traditional Markowitz mean-variance problem. Plus, smarter people here. :-) > On May 3, 2018, at 3:01 PM, Bert Gunter <bgunter.4567 at gmail.com> wrote: > > You can't -- at least as I read the docs for ?optim (but I'm pretty > ignorant

Hi there, I have a numeric vector let say: Vect <- c(12.234, 234.5675, 1.5) Now I want a string vector like: changedVec <- c("012.234", "234.568", "001.500") Would be grateful if somebody help me how can I do that. Thanks and regards, [[alternative HTML version deleted]]

Folks; I am having a problem with the cv.glm and would appreciate someone shedding some light here. It seems obvious but I cannot get it. I did read the manual, but I could not get more insight. This is a database containing 3363 records and I am trying a cross-validation to understand the process. When using the cv.glm, code below, I get mean of perr1 of 0.2336 and SD of 0.000139. When using a

I'm trying to use Rprof() to identify bottlenecks and speed up a particullary slow section of code which reads in a portion of a tif file and compares each of the values to values of predictors used for model fitting. I've written up an example that anyone can run. Generally temp would be a section of a tif read into a data.frame and used later for other processing. The first portion

Hi All, I want to draw samples (n=4) from one of 2 triangular distributions for each value in a matrix. I am using an ifelse statement to try to define which distribution to draw from. >From the output, I can see that the ifelse statement is choosing the correct distribution, however, my n=4 simulations aren't occurring. Is there a way to adjust the ifelse statement to fix this, or must

On Thu, May 3, 2018 at 2:03 PM, Michael Ashton <m.ashton at enduringinvestments.com> wrote: > Thanks Bert. But everyone on that forum wants to use finance tools rather than general optimization stuff! And I am not optimizing a traditional Markowitz mean-variance problem. Plus, smarter people here. :-) > I'm very confused by these statements. Most of the "finance tools"

Hi, I was trying to get error bars in my matplot. I looked at an earlier thread, and the sample code that I made is: #------------------ library(plotrix) mat1 <- matrix(sample(1:30,10),nrow=5,ncol=2) ses <- matrix(sample(1:3,10,replace=T),nrow=5,ncol=2) vect <- seq(20,100,20) rownames(mat1) <- rownames(ses) <- vect colnames(mat1) <- colnames(ses) <- letters[1:2]

Hi Michael, A few comments 1. To add the constraint sum(wgt.vect=1) you would use the method of Lagrange multipliers. What this means is that in addition to the w_i (the components of the weight variables) you would add an additional variable, call it lambda. Then you would modify your optim.fun() function to add the term lambda * (sum(wgt.vect - 1) 2. Are you sure that you have defined