similar to: function problem

Displaying 20 results from an estimated 100 matches similar to: "function problem"

2009 Jul 31
2
another automation question
This code works: x<-letters[1:6] ycols<-23:28 xcols<-rep(c(3,4,5,8),each=length(ycols)) somertime<-function(i,j)somers2(Pred_pres_a_indpdt[,i,,], population[,j]) results<-mapply(somertime,xcols,ycols) How can I make variable "h" work? x<-letters[1:6] ycols<-23:28 xcols<-rep(c(3,4,5,8),each=length(ycols))
2009 Jul 31
1
automation question
I have columns in two tables that need to be compared in order to get a statistic. The function calculating the statistic is somers2. Here are the two columns I must calculate, row by row. name1 name2 1 Pred_pres_a_indpdt[,3,,] population[,23] 2 Pred_pres_b_indpdt[,3,,] population[,24] 3 Pred_pres_c_indpdt[,3,,] population[,25] 4 Pred_pres_d_indpdt[,3,,]
2009 Jul 30
3
for loop for file names
I am trying to load binary files in the following fashion load("pred/Pred_pres_a_indpdt") load("pred/Pred_pres_b_indpdt") load("pred/Pred_pres_c_indpdt") load("pred/Pred_pres_d_indpdt") load("pred/Pred_pres_e_indpdt") load("pred/Pred_pres_f_indpdt") but I would like to set up a for loop to replace the letters a:f Here is what I have so
2006 Jan 04
1
silly, extracting the value of "C" from the results of somers2
Sorry I have a very simple question: I used somers2 function from Design package: > z<- somers2(x,y, weights=w) results are: >z C Dxy n Missing 0.88 0.76 500 0.00 Now I want to call only the value of C to be used in further analyses, but I fail to do it. I have tried: > z$C NULL > z[,C] Error in z[,C]: incorrect number of dimensions and some other silly
2004 Aug 30
1
While installing Hmisc...
Dear R-Gurus: This afternoon I was installing the "Hmisc" package. I use R in Linux (Fedora Core 1 (yarrow)) on a Compaq presario with 128 MB RAM laptop. Opening an R session as a root user (superuser), I issued install.packages("Hmisc") and waited. R downloaded the package, installation was going on, and on the standard output I could see that a list of
2007 Mar 28
1
weight factor in somers2 function
Hi! I?m trying to calculate de C index (concordance probability) through the somers2 function (library Hmisc). I?m interesting on including the sampling effort as a weight factor for the evaluation of model predictions with real data. I?ve some questions about that: first of all I?m not really sure if I can include sampling effort as a weight factor. Since the weight factor should be a numeric
2008 Mar 26
2
pseudo R square and/or C statistic in R logistic regression
Dear all, I am now doing the logistic regression using R. (glm, family=binomial). Besides the standardize summary statistics generated from R, I am also interested in some more informations concerning the model fitting / prediction etc; Particularly I am interested in "pseudo R squar" and "C statistic". I searched the R- help and could only get very limited information. (Post
2006 Apr 18
6
lambda, uncertainty coefficient (& Somers D)
Dear colleagues in R, Has anybody implemented the 1) (Goodman & Kruskal) lambda or the 2) (Thiel's) uncertainty coefficient statistics (in the asymmetric and symmetric forms), or is anyone aware that they might reside in some package? A search in the R archives does indicate that they are (somehow) part of the CoCo package, but I would rather not start learning how to transform my
2007 Feb 19
1
random effect nested within fixed effects (binomial lmer)
I have a large dataset where each Subject answered seven similar Items, which are binary yes/no questions. So I've always used Subject and Item random effects in my models, fit with lmer(), e.g.: model<-lmer(Response~Race+Gender+...+(1|Subject_ID)+(1| Item_ID),data,binomial) But I recently realized something. Most of the variables that I've tested as fixed effects are properties
2004 Jun 04
1
use of "rcorr.cens" with binary response?
Dear R-helpers, I recently switched from SAS to R, in order to model the occurrence of rare events through logistic regression. Is there a package available in R to calculate the Goodman-Kruskal Gamma? After searching a bit I found a function "rcorr.cens" which should do the job, but it is not clear to me how to define the input vectors? Is "x" a vector with the fitted
2005 Nov 25
3
obtaining a ROC curve
Hello, I have a classification tree. I want to obtain a ROC curve for this test. What is the easiest way to obtain one? -Anjali --------------------------------- [[alternative HTML version deleted]]
2008 Mar 06
2
calculate AUC and plot ROC in R
Hi, there: Could someone tell me a simple function of plot ROC curve and calculate AUC in R? My setting is very simple, a column of the true binary response and another column of predicted probabilities. Thanks! Yulei [[alternative HTML version deleted]]
2006 Feb 27
1
clustering
Hi there, Sorry for the double email. Does R have the packages for the following clustering methods? And if it does, what the commands for them? 1. SOM (Self-organization map) 2. Graph partitioning: 3. Neural network 4. Probability Binning Thank you very much! Linda [[alternative HTML version deleted]]
2011 Jun 13
1
Somers Dyx
Hello R Community, I'm continuing to work through logistic regression (thanks for all the help on score test) and have come up against a new opposition. I'm trying to compute Somers Dyx as some suggest this is the preferred method to Somers Dxy (Demaris, 1992). I have searchered the [R] archieves to no avail for a function or code to compute Dyx (not Dxy). The overview of Hmisc has
2004 Mar 11
5
Receiver Operator Characteristic curve
Dear R-helpers: I want to calculate area under a Receiver Operator Characteristic curve. Where can I find related functions? Thank you in advance Xiao
2010 Oct 06
2
A problem --thank you
dear:teacher i have a problem which about the polr()(package "MASS"), if the response must have 3 or more levels? and how to fit the polr() to 2 levels? thank you. turly yours [[alternative HTML version deleted]]
2002 Aug 04
5
Pseudo R^2 for logit - really naive question
I am using GLM to calculate logit models based on cross-sectional data. I am now down to the hard work of making the results intelligible to very average readers. Is there any way to calculate a psuedo analoque to the R^2 in standard linear regression for use as a purely descriptive statistic of goodness of fit? Most of the readers of my report will be vaguely familiar and more comfortable with
2007 Dec 31
2
help on ROC analysis
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 ..................
2009 Jul 17
2
Getting the C-index for a dataset that was not used to generate the logistic model
Does anyone know how to get the C-index from a logistic model - not using the dataset that was used to train the model, but instead using a fresh dataset on the same model? I have a dataset of 400 points that I've split into two halves, one for training the logistic model, and the other for evaluating it. The structure is as follows: column headers are "got a loan" (dichotomous),
2005 Aug 02
5
question on graphs and finding area under a curve
Question on graphs: The default case for drawing a graph in R, is where a little space is left on the x and y axis before the first tick i.e. even if I say xlim=c(0,1) -- there will be some space between the edge of the x-axis and where 0 is placed. If I want 0 on the edge, how do I do it in R? Area under the curve: I have a 45 degree line and a curve above or below it. Is there a way in R