similar to: creation of new variables

Displaying 20 results from an estimated 1000 matches similar to: "creation of new variables"

2008 Jan 29
1
Form Pairs of Variables for a paired t-test
Hi Users, This is regarding the paired t-test. I have 5 variables (say) Data$v1,Data$v2,Data$v3,Data$v4,Data$v5 in my data frame. Now, I need to perform a paired t-test on all the possible 10 pairs.How do I set up the pairs table directly and pass those variables in to t-test. Thanks in advance, Pratap --------------------------------- Now you can chat without
2007 Aug 20
3
Differentiation
Hi, Could anyone tell me what is the command used in R to do 1. Differentiation 2. Newton Raphson method (Numerical Analysis in general...) Are there any packages separately for this? Thanks for your help! BR, Shubha [[alternative HTML version deleted]]
2007 Oct 10
2
Deleting the White Space in an R graph
Hi All, Is there a way we can delete the empty white space around when we generate any graph/map using R? The final output should be onaly a picture with no white spaces all around. Cheers, Pratap --------------------------------- 5, 50, 500, 5000 - Store N number of mails in your inbox. Click here. [[alternative HTML version deleted]]
2006 Sep 20
1
problem coercing truncated character vector to levels
Dear R wizes, I have a data.frame of species abundances with column names consisting of 4 letter codes then an underscore and a number like this: abco_1, abco_2, abco_3, psm_1, psme_2, psme_3, etc. I would like to get an identifier for all the abco, and psme and other species etc. I used spec.fact<-substring(names(spec.count),1,4) To make a vector of the first 4 letters of
2006 Nov 26
1
problem loading package Hmisc
Hi, I installed the package Hmisc with the command install.packages("Hmisc") without errors. When I try to load the library with command library(Hmisc) I get the error > library(Hmisc) Error in library(Hmisc) : there is no package called 'Hmisc' > version _ platform i386-pc-linux-gnu arch i386 os linux-gnu system i386,
2006 Oct 04
1
" Error in "names<-.default"
Hi All, Can some one explain me the following error- " Error in "names<-.default" 'names' attribute [1199] must be the same length as the vector [17]". Thanks, Pratap --------------------------------- [[alternative HTML version deleted]]
2006 Oct 04
2
convert vector to matrix
Hi All, I have vector containing 10 elements(odservations). I need to put this into a matrix, where the matrix should contain only one column. I need this to be done using the cbind command because in the final table I should have a column of attributes( from adifferent vector) and a column of vectors from the matrix above Please suggest me how this can be done Thanks and
2006 Jun 14
3
A question about stepwise procedures: step function
Dear all, I tried to use "step" function to do model selection, but I got an error massage. What I don't understand is that data as data.frame worked well for my other programs, how come I cannot make it run this time. Could you please tell me how I can fix it? ***************************************************************************************************
2013 Feb 01
4
Filter according to the latest data
Hello together, i have a data.frame, like this one: No. Change Date A 123 final 2013-01-15 B 123 error 2013-01-16 C 123 bug fixed 2013-01-17 D 111 final 2013-01-12 and now a want a new data.frame which includes
2006 Aug 23
5
two density curves in one plot?
Hello, I was wondering if I can plot two curves I get from "density(data)" into one plot. I want to compare both. With the following commad, I just get one curve plotted: plot( density(mydata) ) Sorry for this stupid question but I could not find a solution until now... Antje
2006 Sep 27
2
Histogram
Dear all, I want to design a histogram and I need to have the frequency at certain points. For example I have the following 2 columns: *X Y* 0.1 25 0.4 22 0.45 11 0.55 21 I want the chart to have 4 columns. First column is from 0.0-0.1 (on X) and frequency is 25. Next colum is wider and form 0.1-0.4 with 22 frequency. Next column is narrow with 11 frequency and the last column is
2006 Aug 23
1
covariance matrix of predictions
Hi ! I am trying to get at the covariance of the predictions of a linear model. Suppose the we have: > x<-runif(1000) > y<-2 + 25x*x +rnorm(1000) > lm1 <-lm(y~x, data = data.frame(y = y, x=x)) > x.pred <-runif(10) > y.hat <- predict(lm1, newdata = data.frame(x=x.pred)) I was wondering how to get an estimate of the covariance of y.hat which would be a 10 x 10
2006 Sep 30
3
Textmate project drawer: is there a Windows alternative?
I was reading about the project drawer feature in Textmate, which is Mac only. Is there a similar feature in a Windows based text editor that works with R. This feature sounds really useful. Thanks, Graham [[alternative HTML version deleted]]
2006 Oct 27
2
Multivariate regression
Hi, Suppose I have a multivariate response Y (n x k) obtained at a set of predictors X (n x p). I would like to perform a linear regression taking into consideration the covariance structure of Y within each unit - this would be represented by a specified matrix V (k x k), assumed to be the same across units. How do I use "lm" to do this? One approach that I was thinking of
2006 Aug 04
2
plotting picture data
Hi R users I have a dataset which represents points that are market by patients as the source of pain. Basically the patients indicates by a cross on a chest pictures where he/she thinks is the source of pain. The data was then digitalized by divinding the chest into small squares and each square was give value 1 if it was the center 2 if it was touched by the markings and 3 if it was not
2006 Sep 29
6
List-manipulation
Hi, Sorry for the question, I know it should be basic knowledge but I'm struggling for two hours now. How do I select only the first entry of each list member and ignore the rest? So for > $"121_at" > -113691170 > $"1255_g_at" > 42231151 > $"1316_at" > 35472685 35472588 > $"1320_at" > -88003869
2006 Jun 14
2
Saving R graphics with version 2.3.1
HI ! I?ve installed the latest R version (2.3.1) and I?ve had problems to save my graphics as JPEG, PNG and the others available formats. R saves the file with no extension. Then, I have to open this file using an image visualizer and save it as PNG, for instance. Previous R versions work without problems. Has everyone had a similar problem? Is it a bug of R 2.3.1? Thanks in advance. Ilka
2006 Aug 26
1
Implementing EM Algorithm in R!
Hi All, I need some help in how one can implement maximumlikelihood estimation for models with discrete hidden variables in EM in R. Regards [[alternative HTML version deleted]]
2007 Oct 29
3
using survfit
hie when i use plot.survfit to plot more than one graph why I only see the last graph how do i see the other graphs.for example n=20 n1=n/2 n2=n/4 a11=4;a12=4 ;a21=4 ;a22=4 t1<-array(1,c(n1)) t2<-array(2,c(n1)) treatgrp=matrix(c(t1,t2))
2006 Sep 20
8
Statitics Textbook - any recommendation?
I would like to buy a basic statistics book (experimental design, sampling, ANOVA, regression, etc.) with examples in R. Or download it in PDF or html format. I went to the CRAN contributed documentation, but there were only R textbooks, that is, textbooks where R is the focus, not the statistics. And I would like to find the opposite. Other text I am trying to find is multivariate data