search for: szerman

Displaying 20 results from an estimated 22 matches for "szerman".

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2005 Oct 20
5
spliting an integer
Hi there, From the vector X of integers, X = c(11999, 122000, 81997) I would like to make these two vectors: Z= c(1999, 2000, 1997) Y =c(1 , 12 , 8) That is, each entry of vector Z receives the four last digits of each entry of X, and Y receives "the rest". Any suggestions? Thanks in advance, Dimitri [[alternative HTML version deleted]]
2005 Jun 09
1
getting more than the coefficients
...t.xtable(xtable(myfit), file="myfile") only returns the estimated coefficients and the correspondent standard erros, t-statiscs and p-values. But I wish to get a bit more, say, the number of observations used in the regresion, the R^2 and F statistics. Any suggestions? Thanks, Dimitri Szerman [[alternative HTML version deleted]]
2006 Jan 26
1
efficiency with "%*%"
Hi, x and y are (numeric) vectors. I wonder if one of the following is more efficient than the other: x%*%y or sum(x*y) ? Thanks, Dimitri Szerman
2006 Mar 05
1
duration analysis
...my interest is > -myfit$coefficients/myfit$scale The standard erros are easily worked out, as the absolute z-statistics are the same. Ok, so I can get easily what I want from survreg(). But I'd like to get it even more directly. Does anyone know some function to do it? Thank you, Dimitri Szerman
2009 May 12
2
import HTML tables
Hello, I was wondering if there is a function in R that imports tables directly from a HTML document. I know there are functions (say, getURL() from {RCurl} ) that download the entire page source, but here I refer to something like google document's function importHTML() (if you don't know this function, go check it, it's very useful). Anyway, if someone of something that does this
2005 Oct 25
2
Inf in regressions
Hi, Suppose I I wish to run lm( y ~ x + z + log(w) ) where w assumes non-negative values. A problem arises when w=0, as log(0) = -Inf, and R doesn't accept that (as it "accepts" NA). Is there a way to tell R to do with -Inf the same it does with NA, i.e, to ignore it? ( Otherwise I have to do something like w[w==0] <- NA which doesn't hurt, but might be a bit
2005 Jun 24
2
Gini with frequencies
...quencies. On the other had, Lc() compute the Lorenz curve using these frequencies, but I don't manage to use its output to compute the Gini coefficient. I wonder if you have already writen some function to do this, or if you could shed some light here and help me. Thank you very much, Dimitri Szerman [[alternative HTML version deleted]] _______________________________________________________ Instale o discador agora! http://br.acesso.yahoo.com/
2007 Apr 06
2
lm() intercept at the end, rather than at the beginning
Hi, I wonder if someone has already figured out a way of making summary(mylm) # where mylm is an object of the class lm() to print the "(Intercept)" at the last line, rather than the first line of the output. I don't know about, say, biostatistics, but in economics the intercept is usually the least interesting of the parameters of a regression model. That's why, say, Stata
2006 Mar 03
3
memory once again
...import it using read.S(). I even tried to "increase" my memory by memory.limit(4000), but it still didn't work. Regardless of the answer to my question, I'd appreciate to hear about your experience/suggestions in working with big files in R. Thank you for youR-Help, Dimitri Szerman
2007 Apr 05
2
creating a data frame from a list
Dear all, A few months ago, I asked for your help on the following problem: I have a list with three (named) numeric vectors: > lst = list(a=c(A=1,B=8) , b=c(A=2,B=3,C=0), c=c(B=2,D=0) ) > lst $a A B 1 8 $b A B C 2 3 0 $c B D 2 0 Now, I'd love to use this list to create the following data frame: > dtf = data.frame(a=c(A=1,B=8,C=NA,D=NA), +
2006 Apr 24
1
omitting coefficients in summary.lm()
Hi, I'm running a regression using lm(), in which one of the right-hand side variables is factor with many levels (say, 80). I am not intersted in the estimates of the resulting dummies, but I have to include them in my regression equation. So, I don't want the estimates associated with theses dummies to be printed by summary.lm( ). Is there an easy way to do this? Thank you, Dimitri
2006 Apr 29
1
splitting and saving a large dataframe
Hi, I searched for this in the mailing list, but found no results. I have a large dataframe ( dim(mydata)= 1297059 16, object.size(mydata= 145280576) ) , and I want to perform some calculations which can be done by a factor's levels, say, mydata$myfactor. So what I want is to split this dataframe into nlevels(mydata$myfactor) = 80 levels. But I must do this efficiently, that is, I
2006 Jul 05
1
creating a data frame from a list
Dear all, I have a list with three (named) numeric vectors: > lst = list(a=c(A=1,B=8) , b=c(A=2,B=3,C=0), c=c(B=2,D=0) ) > lst $a A B 1 8 $b A B C 2 3 0 $c B D 2 0 Now, I'd love to use this list to create the following data frame: > dtf = data.frame(a=c(A=1,B=8,C=NA,D=NA), + b=c(A=2,B=3,C=0,D=NA), + c=c(A=NA,B=2,C=NA,D=0) ) > dtf a b
2006 Jul 12
1
help in vectorization
Hi, I have two data frames. One is like > dtf = data.frame(y=c(rep(2002,4), rep(2003,5)), + m=c(9:12, 1:5), + def=c(.74,.75,.76,.78,.80,.82,.85,.85,.87)) and the other dtf2 = data.frame(y=rep( c(2002,2003),20), m=c(trunc(runif(20,1,5)),trunc(runif(20,9,12))), inc=rnorm(40,mean=300,sd=150) ) What I want is to divide
2009 Mar 13
1
transforming a matrix
Hello, I have a matrix such as > X = matrix(c(1:4,29,32,56,-45), ncol=2) and I want one like > Y=matrix(c( 1 , 34 , 1 , 34 , 2 , -56 , 1 , 34 , 3 , 27 , 1 , 34 , 1 , 34 , 2 , -56 , 2 , -56 , 2 , -56 , 3 , 27 , 2 , -56 , 1 , 34 , 3 , 27 , 2 , -56 , 3 , 27 , 3 , 27 , 3 , 27 ), ncol=4, byrow=T) How do I do this in an efficient and elegant way? Many thanks, Dimitri [[alternative HTML
2007 Apr 28
1
RWinEdt and Windows Vista
Hi, I have a new computer with Windows Vista and I am trying to use RWinEdt, which I have always used. I am using R version 2.5. The installation of the RWinEdt library is funny. First, it didn't install at all. Then, I uninstalled/reinstalled both R and WinEdt, downloaded the package again from the CRAN repositary, got some error messages, but RWinEdt initialized. I closed R and WinEdt,
2006 May 24
1
multiple destinations in duration (survival) analysis
Hi, I'm trying to estimate a (parametric) competing risks model in the context of duration (or survival, if you wish) analysis. That is, instead of studying the transition of subjects to "death", I wish to study the transitions to multiple *destinations* (which is different from studying multiple *durations*, or recurrent events). I am more interested in the hazard function rather
2018 Jun 01
1
rasterize SpatialPolygon object using a RasterBrick object
I am trying to rasterize a SpatialPolygon object by a RasterBrick object. The documentation of the raster::rasterize function explicitly says this is allowed. Here's what I am doing # load the raster package library("raster") # create a raster brick object using the example from the brick function documentation b <- brick(system.file("external/rlogo.grd",
2009 Nov 15
1
R crashing
Hello, This is what I am trying to do: I wrote a little function that takes addresses (coordinates) as input, and returns the road distance between every two points using Google Maps. Catch is, there are 2000 addresses, so I have to get around 2x10^6 addresses. On my first go, this is what I did: ######################################### getRoadDist = function(X,complete=F){ # X must be a
2006 Apr 26
1
help using tapply
Dear R-mates, # Here's what I am trying to do. I have a dataset like this: id = c(rep(1,8), rep(2,8)) dur1 <- c( 17,18,19,18,24,19,24,24 ) est1 <- c( rep(1,5), rep(2,3) ) dur2 <- c(1,1,3,4,8,12,13,14) est2 <- rep(1,8) mydata = data.frame(id, estat=c(est1, est2), durat=c(dur1, dur2)) # I want to one have this: id = c(rep(1,8), rep(2,8))