similar to: use date as x-axis

Hi, pnorm(-1.53,0,1) under version 3.0.2 gives 0.05155075. I am pretty sure it should be 0.063. Is there something wrong with this version of R? I am using: R version 3.0.2 (2013-09-25) -- "Frisbee Sailing" Copyright (C) 2013 The R Foundation for Statistical Computing Platform: i686-pc-linux-gnu (32-bit) -- Tom [[alternative HTML version deleted]]

Hi, I need to correct for ar(1) behavior of my residuals of my model. I noticed that there are multiple gls models in R. I am wondering if anyone has experience in choosing between gls models. For example, how should one decide whether to use lm.gls in MASS, or gls in nlme for correcting ar(1)? Does anyone have a preference? Any advice is appreciated! Thanks, -- Tom [[alternative HTML

Hi, I would like to use a weighted lm model to reduce heteroscendasticity. I am wondering if the only way to generate the weights in R is through the laborious process of trial and error by hand. Does anyone know if R has a function that would automatically generate the weights need for lm? Thanks, -- Tom [[alternative HTML version deleted]]

Hi, I tried to stack two charts on top of each other using the following R functions: par(mfrow=c(2,1)) plot(rnorm(1:3),xaxt="n",xlab="") plot(rnorm(1:3)) This created two charts, one on top of the other, but there is too much space between them. Does anyone know how to elimiate the space in between the charts? Thanks, -- Tom [[alternative HTML version deleted]]

Hi, I noticed that max(x) returns the maximum value of a vector, but the function doesn't give the user the option of retrieving the row index number instead. If I used max(x) to find the maximum value of vector x, then is there a function I can use to find the index number, or row name, of the maximum value? Thanks, Tom [[alternative HTML version deleted]]

Hi, Does anyone know if R has a built-in function that is equvalent to Excel's percentrank, i.e., returns the rank of a value in a data set as a percentage of the data set? Thanks, -- Tom [[alternative HTML version deleted]]

Hi, I am currently using the following to formate numbers into percentages: x=0.00112 paste(round(x*100,2),"%",sep="") I am wondering if there is a built in R function that does the same. Does anyone know? Thanks, -- Tom [[alternative HTML version deleted]]

Hi, The documentation for scale() states:"If center is TRUE then centering is done by subtracting the column means (omitting NAs) of x from their corresponding columns". But it seems that R is subtracting something else instead of the column mean: > x=c(2,4,3,4,5) > mean(x) [1] 3.6 > x-mean(x) [1] -1.6 0.4 -0.6 0.4 1.4 > scale(x) [,1] [1,] -1.4032928 [2,]

Hi, I have a CSV file with two columns; the first column is date, second column is numbers. I used read.csv() to load the file into the variable temp. Somehow, R could not recognize my numbers as double. Instead, it thinks these numbers are integer even though they all have decimal points (isn't that strange?). The problem I ran into is that if I tried to convert the numbers to double using

Hi, Does anyone know if R has a function that is similar to lag.plot but instead of auto-correlation, it plots cross-correlation with lags? Thanks, -- Tom [[alternative HTML version deleted]]

Hi, I have a 2D chart that is divided into four quadrants, I, II, III, IV: plot(1:10,ylim=c(0,10),xlim=c(0,10),type="n") abline(v=5,h=5) text(x=c(7.5,7.5,2.5,2.5),y=c(2.5,7.5,7.5,2.5),labels=c("I","II","III","IV")) I would like to fill each quadrant with a background color unique to the quadrant. Does anyone know how to do this in R? Thanks, --

Hi, I am trying to reproduce some functionalities of Excel pivot table in R, sadly, I couldn't figure out how to do it. I am wondering if this is even possible in R. Does anyone know? Here is an example: year=rep(2003,16) quarter=rep(1:4,each=4) sales=1:16 company=rep(c("a","b","c","d"),4) df=data.frame(year,quarter,sales,company) #this is the

Hi, I have time series data stored in csv files (see below for an example of the data). I understand that in order to analyze my data in R, I need to first transform it into a ts object. Howeve, I could not find an example on how exactly to do that. Is ts the only function I need? What are the steps that I need to go through to build a time series object from raw data like this? Thanks, Tom

Hi, I am new to R and I have been trying it out. I ran into a problem with the plot() function. Below is my code: > d <- read.table("c:/test/sp.txt",header=0) > spval <- d[,2] > plot(spval,type="l") Warning messages: 1: graphical parameter "type" is obsolete in: plot.window(xlim, ylim, log, asp, ...) 2: graphical parameter "type" is

Hi, I am using aggregate() to add up groups of data according to year and month. It seems that the function aggregate() automatically sorts the levels of factors of the grouping elements, even if the order of the levels of factors is supplied. I am wondering if this is a bug, or if I missed something important. Below is an example that shows what I mean. Does anyone know if this is just the way

Hi, I am trying to extract data from a ts object by month, e.g., extract Jan, Feb, and Aug data from a monthly ts object. I tried the following but it didn't work: > xa=1:50 > ta=ts(xa,start=c(1990,1),frequency=12) > ta[cycle(ta)==c(1,2)] # this method works but it's not what I want [1] 1 2 13 14 25 26 37 38 49 50 > ta[cycle(ta)==c(1,2,8)] # this method doesn't work,

Hi, Sometime when I attach a dataset, R gives me the following message/warning:"The following object(s) are masked from package:datasets: column_name". Does anyone know what it means? Since it seems that the dataset was attached and I could manipulate the data from the dataset without problems, I am wondering what was R trying to tell me. Thanks, Tom [[alternative HTML version

Hi, Suppose I already have two plots on the same screen, and I want to draw lines in each of them. Is that possible in R? It seems that once you have two plots on the screen, you can only draw lines in the the last plot, never the 1st. Here is what I mean: #some data y1=rnorm(1:3) y2=rnorm(1:3) #draw two plots on the same screen par(mfrow=c(2,1),oma = c(6, 0, 5, 0)) par(mar=c(0, 5.1, 0, 5.1))

Hi, I have two sets of data that I would like to put into a data frame. But since they have different length, I am not sure how to do this. Here is an example of my data: data set one: date growth 1/1/2007 10 1/2/2007 10.2 1/3/2007 10.4 1/4/2007 10.6 data set two: date growth 1/1/2007 22 1/2/2007 22.5 1/4/2007 22.4 I would like to combine the two data sets and

Hi, I looked up the help file on sample(), but didn't find the info I was looking for. When sample() is used to resample from a distribution, e.g., bootstrap, how does it do it? Does it use an uniform distribution, e.g., runif(), or something else? And, when the help file says:"sample(x) generates a random permutation of the elements of x (or 1:x)", would I be correct if I