similar to: How can I understand this sentence,and express it by means of Mathematical approach？

hello, my problem is like this: now after processing the varibles, the remaining 160 varibles(independent) and a dependent y. when I used PLS method, with 10 components, the good r2 can be obtained. but I donot know how can I express my equation with the less varibles and the y. It is better to use less indepent varibles. that is how can I select my indepent varibles. Maybe GA is good

Dear all, Objective: I am trying to learn about neural networks. I want to see if i can train an artificial neural network model to discriminate between spam and nonspam emails. Problem: I created my own model (example 1 below) and got an error of about 7.7%. I created the same model using the Rattle package (example 2 below, based on rattles log script) and got a much better error of about

In my disk C:/ have a a.csv file, I want to read it to R, importantly, when I use x=read.csv("C:/a.csv") ,the x format is data.frame, I want to it to become matrix format, how can I do it ? thank you! -- View this message in context: http://old.nabble.com/how-can-I-convert-.csv-format-to-matrix----tp26156643p26156643.html Sent from the R help mailing list archive at Nabble.com.

I want to get the plot like this, http://n4.nabble.com/file/n1839303/%25E9%25A2%2591%25E7%258E%2587%25E5%2588%2586%25E5%25B8%2583%25E5%259B%25BE%25E6%25A0%2587%25E5%2587%2586.jpg %E9%A2%91%E7%8E%87%E5%88%86%E5%B8%83%E5%9B%BE%E6%A0%87%E5%87%86.jpg not this, http://n4.nabble.com/file/n1839303/R.jpg R.jpg and the data here, thank you! http://n4.nabble.com/file/n1839303/y1.txt y1.txt can R

Hi list, After a lot of tweaking i have managed to create a histogram with an overlaying density plot. The histogram shows a sample of birth weights of babies and the density plot shows birth weights from a much larger reference populaton. My data is divided in 0.1 Kg bins so in the code below binweigh=0.1. The trouble with the current graph is that it is not very clear since the density plot

I want to split my whole dateset to training set and test set, building model in training set, and validate model using test set. Now, How can I split my dataset to them reasonally. Please give me a hand, It is better to give me some R code. and I see some ways like using SOM to project whole independents to 2-dimensions and find some to be training set and others are test set. like below. I

Dear list, Did anybody have something like multiroot(), similar to uniroot() only for several varibles/function? I know the difficulty several varibles bring. But for nice functions, it can be useful. We are thinking of writing one....I thought to ask first. Mai Zhou -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read

Dear all, My double for loop as follows, but it is little efficient, I hope all friends can give me a "vectorized" program to replace my code. thanks x: is a matrix 202*263, that is 202 samples, and 263 independent variables num.compd<-nrow(x); # number of compounds diss.all<-0 for( i in 1:num.compd) for (j in 1:num.compd) if (i!=j) { S1<-sum(x[i,]*x[j,])

Hello all, I am trying to use stepwise procedure to select covariates in Cox model and use bootstrap to repeat stepwise selection, then record how many times variables are chosen by step() in bootstrap replications. When I use step() (or stepAIC) to do model selection, I got errors. Here is the part of my code for (j in 1:mm){ #<--mm=10 for (b in 1:nrow(reg.bs)){ #<--bootstrap 10

I am learning the package "caret", after I do the "rfe" function, I get the error ,as follows: Error in `[.data.frame`(x, , retained, drop = FALSE) : undefined columns selected In addition: Warning message: In predict.lm(object, x) : prediction from a rank-deficient fit may be misleading I try to that manual example, that is good, my data is wrong. I do not know what

Hello, I wonder when I do coxph in R: coxph( Surv(start, stop, event) ~ x, data=test) If x is a categorical varible (1,2,3,4,5), should I creat four dummy varibles for it? if yes, how can I get the overall p value on x other than for each dummy variable? Thanks Lisa Wang Princess Margaret Hospital Phone 416 946 4501

hi everyone, I am wondering if I can inintial all of the varibles and vectors at the begining part of my R script to make clear all the meanning defined in another script runned before It is just similiar with the command " close all " in Matlab or "reinit " in grads.How can I do? thank you.:) -- TANG Jie Email: totangjie@gmail.com Tel: 0086-2154896104 Shanghai Typhoon

rm(list=ls()) yx.df<-read.csv("c:/MK-2-72.csv",sep=',',header=T,dec='.') dim(yx.df) #get X matrix y<-yx.df[,1] x<-yx.df[,2:643] #conver to matrix mat<-as.matrix(x) #get row number rownum<-nrow(mat) #remove the constant parameters mat1<-mat[,apply(mat,2,function(.col)!(all(.col[1]==.col[2:rownum])))] dim(yx.df) dim(mat1) #remove columns with numbers of

Hello, I'm running samba 3.02 on freebsd 4.7. Client systems are WinXP Pro Srv Pk 1. Anyway, the logon script has issues, I added a pause statement to view it. It says: There are open files and/or incomplete directory searches pending on the connection to Z: The command completed successfully. Z:\>NET USE H: /HOME The current directory is invalid. END. Where did Z: come from??? I

Dear all, Some functions like 'ROC(Epi)' can be used to perform ROC analyssi, but it needs us to specify the fitting model in the argument. Now i have got the predicted p-values (0,1) for the 0/1 response variable using some other approach, see the following example dataset: id mark predict.pvalue 1 1 0.927 2 0 0.928 3 1 0.928 ..................

e.g. a= a b c d e 1 1 1 3 1 1 2 1 2 3 4 5 3 1 3 3 8 3 4 1 4 3 3 5 5 1 1 3 1 1 I want to delete colume a and colume c, because they have the same values in every row, then ,I want to get this data.frame . b= b d e 1 1 1 1 2 2 4 5 3 3 8 3 4 4 3 5 5 1 1 1 the following is my code but it's wrong. rm(list=ls()) a=c(1,1,1,1,1); b=c(1,2,3,4,1); c=c(3,3,3,3,3);

my programe is below: a=c(1,2,1,1,1); b=c(1,2,3,4,1); c=c(3,4,3,3,3); d=c(1,2,3,5,1); e=c(1,5,3,5,1) data.f=data.frame(a,b,c,d,e) origin.data<-data.f cor.matrix<-cor(origin.data) origin.cor<-cor.matrix m<-0 for(i in 1:(cor.matrix[1]-1)) { for(j in (i+1):(cor.matrix[2])) { if (cor.matrix[i,j]>=0.95) { data.f<-data.f[,-i]; i<-i+1 }

Hello forum, I want to find in survey how to test V-cramer and coefficient Goodman-Kruskal gamma, to test the collinearity between varibles to enter a model. For the V-Cramer function is used with the package vcd assocstats but without considering the survey package. I appreciate the cooperation. Att. Diana Martinez [[alternative HTML version deleted]]

Is it possible to check certain varibles on the live system, for example, what the current setting for pridialplan is? I know what is set in the config files, but the behaviour does not reflect this. Can this be checked? Kind Regards: Gabriel -------------- next part -------------- An HTML attachment was scrubbed... URL:

What does Generalized Cross Validation score mean. I preform and ordisurf on an ordination (nmds) with an environmental variable. I am trying to figure out "how well" the environmental varibles predict/explain the sites placements in species space. Any help would be greatly appreciated. Any pointers to literature... would be welcome. thanks in advance, -- Stephen Sefick Research