similar to: reading header in txt file and making histogram

Dear R help list, I am modeling some survival data with coxph and survreg (dist='weibull') using package survival. I have 2 problems: 1) I do not understand how to interpret the regression coefficients in the survreg output and it is not clear, for me, from ?survreg.objects how to. Here is an example of the codes that points out my problem: - data is stc1 - the factor is dichotomous

Hello can anyone help please? i read two words "cell1", "cell2" into a list. I want to turn this list into a factor. > cell_data <-list(c('cell1','cell2')) > cell_data [[1]] [1] "cell1" "cell2" > factor_list <- factor(cell_data) Error in sort.list(y) : 'x' must be atomic for 'sort.list' Have you called

1. The weibull is the only distribution that can be written in both a proportional hazazrds for and an accelerated failure time form. Survreg uses the latter. In an ACF model, we model the time to failure. Positive coefficients are good (longer time to death). In a PH model, we model the death rate. Positive coefficients are bad (higher death rate). You are not the first to be confused

I ran into a problem with "subset" while working at home that I am not sure is a bug or not. I defined a custom function to take a data frame of tree positions, sizes, and types (containing the columns TRT, COMP, PLOT, X, Y, DBH and CON) and wanted to make a stem map of the plot using different symbols and colors to represent the different types of tree stems. I copied a bit of the

Thanks for sharing the questions and responses! Is it possible to appreciate how much the coefficients matter in one or the other model? Say, using Biau's example, using coxph, as.factor(grade2 == "high")TRUE gives hazard ratio 1.27 (rounded). As clinician I can grasp this HR as 27% relative increase. I can relate with other published results. With survreg the Weibull model gives a

Hey, So I have a scatter plot and I am trying to plot a curve to fit the data based on a Holling Type III functional response. My function is this: nll2<-function(a,b) { conefun<-(a*DBH^2)/(b^2+DBH^2) nlls2<-dnbinom(x=cones ,size=DBH, mu=conefun,log=TRUE) -sum(nlls) } and my plot is this: plot (DBH,cones) DBH is on the x-axis and cones is on the y-axis. How do I get the curve

Now I have the forest plot data with x, y locations, and I measured the DBH for every indivicuals. The data looks like that: x=runif(100,0,100) y=runif(100,0,100) dbh=runif(100,1,100) rdata=data.frame(x,y,dbh) > rdata[1:5,] x y dbh 1 99.5354145 1.412844 34.10112 2 0.8259361 87.737036 39.12914 3 6.5678613 65.699032 22.55990 4 67.2987881 72.053877 45.83978 5 2.2491372

Hi, I'm trying to plot an equation in two variables to get a feel for sensitivity to its parameters. I've run expand.grid to get made-up vectors of the combinations of the two independent variables, and am trying to plot the output of the dependent, M, against both the dependent in a 3d space. t <- 0:100 DBH <- 10:100 TxDBH<-expand.grid(t,DBH) time<-TxDBH[,1]

Hi Guys, this is actually a thread of emails, but for some reason, even though i am a member, it's withholding my email so i said i would try it this route instead!... I appreciate the reading Thank you. If i have: matrix: > var1 var2 var3 > cell1 x x x > cell2 x x x > cell3 x x x > > cell4 > > . > .

Hello, I have a problem with my script. I don'y know how to apply subtitles. I have 9 charts per page (for combination of 3 blocks and 3 treatments). I want to have subtitles for this interaction (e.g. Block A Trt 1, Block A Trt 2, ...) MBE$bt<- interaction(MBE$Block,MBE$trt) par(mfrow=c(3,3)) for(i in unique(MBE$bt)){ ss <- MBE$bt==i plot(MBE$Year[ss], MBE$DBH[ss])

Hello, I have a big table with 3 columns and 103918 rows. This is the example,            time             species                 dbh 5 1 4.9377297 575 1 11.64127213 575 1 109.8182438 575 1 8.029809521 5 1 24.32501874 575 1 4.895992119 575 1 11.40567637 575 1 2.795090562 575 1 21.79281837 575 1 52.57476174 575 1 27.7290919 575 1 3.23262083 575 2 19.30612651 575 1

I've been trying to figure out how to prevent a column that is the result of an aggregate function call so that I can use it in further calculations. For example, I would like to aggregate the expf for the data.frame by sp (character) and dbh (double d=rounded to integer) using the command: > st2 <- aggregate( ntrs$expf, by=list(sp=ntrs$sp,dbh=ntrs$dbh), sum ) > st2$expf <- st2$x

Dear R-help, Here's a simple example of nonlinear curve fitting where nls seems to get the answer wrong on a very simple exponential fit (my R version 2.7.2). Look at this code below for a very basic curve fit using nls to fit to (a) a logarithmic and (b) an exponential curve. I did the fits using self-start functions and I compared the results with a more simple fit using a straight lm()

R gurus, I'm working on data analysis for a small project. My response variable is total vines per tree (median = 0, mean = 1.65, min = 0, max = 24). My predictors are two categorical variables (four sites and four species) and one continuous (tree diameter at breast height (DBH)). The main question I'm attempting to answer is whether or not the species identity of a tree has

Dear all, As part of a larger function, I am randomly removing rows from a data frame. The number of removed rows is determmined by a Poisson distribution with a low mean. Sometimes, the random number is 0, and that's when the problem starts: My data frame: > temp occ x y dbh age 801 0 2977.196 3090.225 6 36.0 802 0 2951.892 3083.769 8 40.6 803 0 2919.111

Dear people of the help list I am drying to analyze my data using the 'lmer' function and I keep having problems. This is the model: > fm1<-lmer(dbh~spec+scheme+(1|Plot),data=d, REML=FALSE). I analyse tree size (dbh) of 3 different species (spec) and 3 planting schemes (scheme). I have 5 plots, which I hope to model as a random factor. (However, the subsequent output is based on

*Good day!* I'm using Vista(x64) and R 2.13.0(x64) (with ncdf and RnetCDF packs) *I have a problem:* I'm trying to open **.nc* file and I use this script (http://r.789695.n4.nabble.com/Problem-downloading-and-opening-netcdf-file-td3046897.html#a3046965) library(ncdf) link <- "http://ibis.grdl.noaa.gov/SAT/SeaLevelRise/slr/slr_sla_gbl_free_all_66.nc" dest <-

Dear All, I seem to have stumbled across an AGI problem; I have written an AGI Script (bottom of this email); The script does the following; Makes a CDR entry when called Records the call Updates the CDR Finds a corresponding DNIS from the SMDR table (captured via a serial port logger) Matches up the record and updates the CDR. The script works perfectly in my test lab and has been doing so

Hi there, I trying to solve this problem for the whole day not going anywhere, so I really hope maybe somebody can help me in this community... I've got an object coefficient2 which I want to plot in differerent ways, with colors and labels added to the points, but somehow there seems to be a problem if a value is NA within the independent variable, resulting in false labels and false colors

hi,guys- I have a mysql database which stores host informations,so I wrote a function to get some values. - Here is the function rb(this function should return the type I defined in the database): #hosttype.rb require "mysql" module Puppet::Parser::Functions newfunction(:hosttype, :type => :rvalue, :doc => "Gets host type from db.") do |args|