Displaying 20 results from an estimated 400 matches similar to: "silly, extracting the value of "C" from the results of somers2"
2005 Dec 26
0
evaluation methods for logistic regression with proportion data
Dear list-members,
I have made a logistic regression analysis of the spatial distribution of
an ecological phenomenon (wildlife-caused crop damage). I divided the
region into 5x5 km grids, and in each grid I have performed a number of
questionnaires to asses the presence of crop damage in particular houses.
As a result, my dependent variable is not a simple presence/ absence data
but a
2008 Feb 20
3
reshaping data frame
Dear all,
I'm having a few problems trying to reshape a data frame. I tried with
reshape{stats} and melt{reshape} but I was missing something. Any help is
very welcome. Please find details below:
#################################
# data in its original shape:
indiv <- rep(c("A","B"),c(10,10))
level.1 <- rpois(20, lambda=3)
covar.1 <- rlnorm(20, 3, 1)
level.2
2006 Nov 30
1
scaling y-axis to relative frequency in multiple histogram (multhist)
Hi,
I'm plotting a multiple histogram using the function multhist {package
plotrix}, something like:
library(plotrix)
mh <- list(rnorm(200, mean=200, sd=50), rnorm(200, mean=250, sd=50))
multhist(mh)
In this graph y-axis represents the frequency of observations.... but I
would like it to be scaled into relative frequencies,
does anybody know how to do this with multhist or similar
2008 Feb 22
1
fitting a lognormal distribution using cumulative probabilities
Dear all,
I'm trying to estimate the parameters of a lognormal distribution fitted
from some data.
The tricky thing is that my data represent the time at which I recorded
certain events. However, in many cases I don't really know when the event
happened. I' only know the time at which I recorded it as already happened.
Therefore I want to fit the lognormal from the cumulative
2007 Mar 01
1
how to apply the function cut( ) to many columns in a data.frame?
Dear useRs,
In a data.frame (df) I have several columns (x1, x2, x3....xn) containing
data as a continuous numerical response:
df
var x1 x2 x3
1 143 147 137
2 93 93 117
3 164 39 101
4 123 118 97
5 63 125 97
6 129 83 124
7 123 93 136
8 123 80 79
9 89 107 150
10 78 95 121
I want to
2006 Jan 12
4
Loading Excel file into Limma
Dear mailing group,
This is my first time here. Glad to have this resource!
I am currently trying to load an Excel file into R (limma package loaded)
using the source(*name of directory*) command, but it cannot open the file.
I renamed the file as .R and .RData, to no avail. The Excel data contains
one gene name per row and about 100 data points per gene (columns).
I am only used to
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
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,,]
2007 Feb 28
0
no df to test the effect of an interaccion on a lmer mixed model
Dear useRs,
I am fitting a mixed model using the function lmer from the package lme4,
but I have some problems when I try to test the effect of my factors of
interest.
First let me explain the structure of the model:
I'm measuring animal movements. Explicitly, I am interested in displacement
(straight-line distance from an initial point). Displacements are measured
longitudinally, with one
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
function problem
I have a series of columns that need to be evaluated in various tables. I
need to apply a function in the following manner somers2(name1,name2). name1
is a vector of x inputs for the function which correspond to a vector of y
inputs in name2.
y<-rep(c(3,4,5,8),6)
z<-rep(c(23,24,25,26,27,28),4)
name1<-sprintf("Pred_pres_%s_indpdt[,%s,,]",x,y)
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
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
2008 Mar 18
3
UNSOLITED E_MAILS: Integrate R data-analysis projects with Microsoft Office for free
Dear R Admins,
I received an unsolicited e-mail from BlueInference as an R
user. Does it mean that R that our e-mails (and names) is
sharing it's user database with third parties without our
consent? Or perhaps the BlueInference guys are using an
e-mail address miner to get our contact details?
[SNIP]
Dear Gorden Jemwa,
As a fellow R user, I am sure you agree with me that R is a
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 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
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
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
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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