similar to: Large data sets in R

I have a problem with finding the inverse of a matrix. I have a square 9x9 matrix, A, and when I do solve(A) to find the inverse I get the following error message: Error in solve.default(A) : singular matrix `a' in solve Has anybody got any ideas as to why this is happening? Thanks Laura Gross _______________________________________________________________________ Never pay another

Dear list Having read through all the archives of the mailing lists, I've had no luck finding the answer to my problem. I am running a for(i in 1:n) loop and am creating a matrix, p, for each of the n observations. This matrix p is a 2x1 matrix. I am then doing the following: diagp<-diag(c(p[1,1],p[2,1])) to create a matrix with the elements of P on the diagonal (i.e. a 4x4 matrix).

Hi I am wanting to fit some multinomial logit models (multinom command in package nnet) Is it possible to do any model checking techniques on these models e.g. residual, leverage etc. I cannot seem to find any commands that will allow me to do this. Many thanks ---------------------- L.E.Gross L.E.Gross at maths.hull.ac.uk

Dear list Thanks to all who answered my query yesterday regarding the maximum size of a matrix in R. I have a couple more questions to ask with being new to R! 1. Having imported my data into R from SPSS, I have a data.frame consisting of several variables. I am wanting to store my response variable, Y, and four explanatory variables, X, in vectors/matrices. How can I do this in R? 2. If I

Dear list I have what is probably a very simple question that I can't seem to solve. I basically want to create a vector at the end of a 'for' loop that will store the output for each person and which I can recall after the loop has run. This will require some sort of indexing. X and Y are matrices defined earlier for each person (within the for loop but I'm not writing it here

I'm wanting to create a series of near-identical matrices via the addition of "white noise" to my starting matrix. Is there a function within R which will allow me to do this? Thank you Laura Quinn Institute of Atmospheric Science School of Earth and Environment University of Leeds Leeds LS2 9JT tel: +44 113 343 1596 fax: +44 113 343 6716 mail: laura at env.leeds.ac.uk

I have a total mental block and can't find my way around this seemingly simple problem: I have created a function such that: my_answer_1=myfuntion(my_input_1) I am wanting to perform this calculation over a large number of datasets, but am having real difficulty calling and assigning - i think the problem les in the fact that I need to paste for call and assign. this is my best attempt so

I have a list containing 48 objects (each with 30 rows and 4 columns, all numeric), and wish to produce 4 boxplot series (with 48 plots in each) , one for each column of each object. Basically I want a boxplot from boxplot(mylist[[]][,i]) for i in 1:4. It seems that I can create a boxplot of length 48 from the entire list, but I don't seem able to subscript to return 4 boxplots from the list

Dear list I'm using the reshape command and want to reshape a wide data set to a long one e.g. I have the variables y1,y2,y3,age1,age2,age3,sex,ethnic I want my new long data set to consist of the variables y (which has been created from y1,y2,y3), age (which has been created from age1,age2,age3), sex and ethnic I have tried to use the command:

Dear List I have installed the 'lattice' package by using 'install.package("lattice") It appears to have created a lattice folder in my R library as I would expect. I have tried to call the package by library(lattice) but I am getting the following error message: Error in parse(file, n, text, prompt) : syntax error on line 2018 Could anybody tell me why this is

I am dealing with a huge matrix in R (20 columns, 54000 rows) and have lots of missing values within the dataset which are currently displayed as the value "-999.00" I am trying to create a new matrix (or change the existing one) to display these values as "NA" so that I can then perform the necessary analysis on the columns within the matrix. The matrix name is temp and the

Hi there, I've looked through the very helpful advice about adding fitted lines to plots in the r-help archive, and can't find a post where someone has offered a solution for my specific problem. I need to plot logistic regression fits from three differently-sized data subsets on a plot of the entire dataset. A description and code are below: I have an unbalanced dataset

Hi, Just a quick query - if I'm creating a function to produce a number of histograms per page of output (one per column from a matrix), how can I pass the column name of the matrix into the title (or indeed to form part of the x-axis label)? TIA, Laura Laura Quinn Institute of Atmospheric Science School of Earth and Environment University of Leeds Leeds LS2 9JT tel: +44 113 343 1596 fax:

Hi, I am using the nlme package to fit random effects models, however, I have many missing values in my response variable which I cannot just omit. I can't replace the missing values with the mean or median either as this is too simple and would need to use something like imputation or the EM Algorithm. Is there any way of including these missing values since the model will not run when

Dear R users, I am in trouble using the function solve(matrix) in a loop. When it happens that I have a singular matrix, I get an error message saying so and the loop stops. My question is if there in any way to keep on going in the loop. Thank you in advance, Laura *---------------------------------------------------------* Laura Antolini, PhD Department of

Hello, I am trying to use optim() on a function involving a summation. My function basically is a thinned poisson likelihood. I have two parameters and in most cases optim() does a fine job of getting the minima. I am simulating my data based on pre specified parameters, so I know what I should be getting. However when my true parameters fall in a particular range, optim() gives

Hi, Is it possible to recreate "smoothed" data sets in R, by performing a PCA and then reconstructing a data set from say the first 2/3 EOFs? I've had a look in the help pages and don't seem to find anything relevant. Thanks in advance, Laura Laura Quinn Institute of Atmospheric Science School of Earth and Environment University of Leeds Leeds LS2 9JT tel: +44 113 343 1596

Can the expm function be used to calculate the exponential of a matrix where the matrix is multiplied by a vector in a data frame? For example for (i in 1:length(y)){ expmN<-expm(Q*y[i]) Q<-Matrix(c(1, 2, 3, 4), 2, 2) return(expmN) } Sorry I am new to R and I have been finding it difficult to get information on calculating Matrix exponentials in R. Many thanks in

Ok, I have reinstalled R-1.9.0 and this appears to have fixed the problems I was having with png(). However, I have a further question regarding png() Is it possible to pass a par() argument to the png() command? I am wanting to produce 4 plots per object, which I normally acheive on an X window by par(mfrow=c(1,4)). I have tried calling a new plot and setting par in this way but this has no

??????? Original Message ??????? On Thursday, April 11, 2019 12:55 AM, John Fawcett via dovecot <dovecot at dovecot.org> wrote: > On 11/04/2019 00:51, Laura Smith via dovecot wrote: > > > ??????? Original Message ??????? > > On Wednesday, April 10, 2019 11:48 PM, John Fawcett via dovecot dovecot at dovecot.org wrote: > > > > > On 11/04/2019 00:18, Laura