similar to: time difference (from date function)

Dear all, I have a probability of presence of distribution of a species of interest (varying from 0 to 1 in continuous form) and I have a set of points where I know that species really occurs. But I don´t have points of absence. So, for each true presence I know the estimated presence. I would like to know how can I compute AUC, taking account these Available data. Best wishes,

Dear all I have a code like x<-1:10 y1<-x+runif(10)*2 y2<-seq(0,50,length.out=10)+rnorm(10)*10 par(mfrow=c(1,2)) plot(y1~x) plot(y2~x) Now I would like to plot y1 and y2 on the same graph, with its two scales (y1 on left and y2 on rigth side). Any help are welcome. Kind regards Miltinho Brazil [[alternative HTML version deleted]]

Dear all, I have a data.frame like the sample below, and I would like to expand my data.frame using "population" variable. So, for each line of my data.frame I would like that the new data.frame have many rows as the population collumn. place<-c("place1", "place2", "place3", "place4", "place5") population<-c(100,200,300,50,30)

Dear all, I have a set of x,y,z points obtained from a lizard species and now I would like to estimate the three-dimensional use of space for this species. I know that 2D area I can estimate using adehabitat packages, but I don´t know how to estimate the volumetric space. Any help are welcome. Miltinho Brazil [[alternative HTML version deleted]]

Dear all, I need to run a interactive procedure where the user will need click on the screen (over a XY plot) and I need to record the XY coordinate which the user clicked. Roughly I wrote a short code below. You see that I suppose that the user will choose four coordinates inside the region of intersection between three segmentes. On each click, I would like to record the position clicked in a

Dear all, I know that it is a know issue, but I would like to change the type of font on my plot, and I am not sure the rigth way. I would like to use Times New Roman font, but according to the "par()" help, some device allow we choose an family of fonts. I tryed par(family="times") without success. Surfing on R archieve I got an suggestion of use par(font.lab=6), but when I

Dear all, I have strong interest on Ecological Niche Model, which in general use a set of environmental variables (continuous, categorical etc) and Presence (or Presense/Absence) records for species. I think that "grasp" and "adehabitat" packages could help me on these tasks. My input layers are on ASC format, and the record of species is a data-frame with X, Y, name of

I am trying to produce a simple plot where the points in the plot are actually integers from my data. That is, I am making a length/width plot and I would like the points, rather dots or triangles, appear as different numbers corresponding to a column in my data. I have tried using this: ...,pch="column title" but this merely returns the first letter of the column title, B. Is there

Dear All, I have a set of environental maps and presence-only points for some species. How can I generate distributions models on R using these presence-only data? What packages and functions can I use to do so? Kind regards, Miltinho Brazil [[alternative HTML version deleted]]

I am a beginner in R with a background in SAS. Are there built-in R methods of reading dates for calculating elapsed days between two calendar dates? If so, are there any examples I can browse? Thanks in anticipation. John Byrne. Lecturer in Information Systems. Australian Catholic University.

Dear all, I have some data.frame and I would like (1) change the format of y=axis to escape of scientific format (like 1e+05...) and (2) label the value or other variable on the top of the bar. df<-data.frame(x=1:6,y=c(100,500,1000,25000,500000,1000000)) barplot(df$y,names.arg=df$x) Thanks in advance, miltinho Brazil [[alternative HTML version deleted]]

Dear R list: I modelled changes in a variable (mconc) over time (d) for individuals (replicate) given one of three treatments (treatment) using: mconc.lme <- lme(mconc~treatment*poly(d,2), random=~poly(d,2)|replicate, data=my.data) summary(mconc.lme) shows that the linear coefficient of one of the treatments is significantly different to zero, viz. Value Std.Error

Hi, How can I make the cor(x, y, method="spearman") call to produce an error when the input to it (x, y) produces an error? Here is a simple example: > a <- c(0, 1, 2) > b <- c(100, 2, 4) ## error: > log(a) [1] -Inf 0.0000000 0.6931472 ## error, as expected: > cor(log(a), log(b), method="pearson") [1] NaN ## not an error any more (not expected): >

Dear all, I installed xlsReadWrite package under Windows 7, and got error when trying to run xls.getshlib(). Please, see the errors below: > require(xlsReadWrite) Loading required package: xlsReadWrite xlsReadWrite version (cran shlib) Copyright (C) 2010 Hans-Peter Suter, Treetron, Switzerland. !! Your installation contains the cran placeholder shlib (dll/so). Please get the regular shlib

Dear all, I have several sets of x-y-z points and I need to estimate the volume that encompass all my points. Recently I got some adivice to show the "convex hull" of my points using geometry package (see code below). But now I need to calculate the volume of my set of points. Any advice are wellcome. Thanks in advance Miltinho Astronauta Brazil ----- require(geometry) library(rgl)

Hi there, I´m trying to use "simecol" package but I got the error showed below. I´m runnig R version 2.4.0 (2006-10-03). Kind regards, miltinho Brazil --- > require(simecol) Loading required package: simecol Error in loadNamespace(package, c(which.lib.loc, lib.loc), keep.source = keep.source) : in 'simecol' methods specified for export, but

Hello, I'm trying to superimpose a line plot onto a histogram but I'm not having any luck. I've attached the dataset. What I did was: > hist(data,freq=F) Now I'm trying to superimpose the following points with a line connecting them onto the histogram: x y 100 0.535665393824959 200 0.212744329736556 300 0.0844933242968584 400 0.0335572838043417 500

Dear all, Is there a way of I deal with more than one kind of separators when reading a asc file using scan() function? The separators could be ":", "\t" and ";". Kind regards miltinho [[alternative HTML version deleted]]

Dear all, I have a data.frame with some NAs that can happens anywere, and I would like to keep only rows without NAs. Thanks in advance for your help, and Merry Xmas. myvect<-runif(100) myvect[sample(1:100)[1:5]]<-NA myDF<-data.frame(matrix(myvect,ncol=5)) myDF miltinho [[alternative HTML version deleted]]

Hi there, I have a binary matrix (dim 100x100) filled with values 0 and 1. I need select a record "n" positions of that matrix when values are 1. How can I do that? Thanks for all, Miltinho Brazil --------------------------------- [[alternative HTML version deleted]]