Displaying 20 results from an estimated 1000 matches similar to: "for loops and counter interpolation"
2013 Nov 07
1
R interface to C API Rf_logspace_{add,sub}?
Is there an R-language interface to the R API C-language functions Rf_logspace_add()
and Rf_logspace_sub()? I don't see one but I may not looking under the
right name.
Various packages have functions which do that same sort
of thing (log(exp(x)+exp(y)) and log(exp(x)-exp(y)) without unnecessary
floating point errors). They have names like
matrixStats::logSumExp(lx, na.rm=FALSE, ...)
2012 May 26
1
Kolmogorov-Smirnov test and the plot of max distance between two ecdf curves
Hi all,
given this example
#start
a<-c(0,70,50,100,70,650,1300,6900,1780,4930,1120,700,190,940,
760,100,300,36270,5610,249680,1760,4040,164890,17230,75140,1870,22380,5890,2430)
length(a)
b<-c(0,0,10,30,50,440,1000,140,70,90,60,60,20,90,180,30,90,
3220,490,20790,290,740,5350,940,3910,0,640,850,260)
length(b)
out<-ks.test(log10(a+1),log10(b+1))
# max distance D
2006 Aug 07
3
Finding points with equal probability between normal distributions
Dear mailing list,
For two normal distributions, e.g:
r1 =rnorm(20,5.2,2.1)
r2 =rnorm(20,4.2,1.1)
plot(density(r2), col="blue")
lines(density(r1), col="red")
Is there a way in R to compute/estimate the point(s) x where the density of the
two distributions cross (ie where x has equal probability of belonging to
either of the two distributions)?
Many Thanks
Eleni
2009 Mar 12
3
help with predict and plotting confidence intervals
Dear R help,
This seems to be a commonly asked question and I am able to run examples that have been proposed, but I can't seems to get this to work with my own data. Reproducible code is below. Thank you in advance for any help you can provide.
The main problem is that I can not get the confidence lines to plot correctly.
The secondary problem is that predict is not able to find my object
2006 Sep 25
2
Multiple imputation using mice with "mean"
Hi
I am trying to impute missing values for my data.frame. As I intend to use the
complete data for prediction I am currently measuring the success of an
imputation method by its resulting classification error in my training data.
I have tried several approaches to replace missing values:
- mean/median substitution
- substitution by a value selected from the observed values of a variable
- MLE
2006 Jul 27
2
memory problems when combining randomForests [Broadcast]
You need to give us more details, like how you call randomForest, versions
of the package and R itself, etc. Also, see if this helps you:
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/32918.html
Andy
From: Eleni Rapsomaniki
>
> Dear all,
>
> I am trying to train a randomForest using all my control data
> (12,000 cases, ~ 20 explanatory variables, 2 classes).
> Because
2005 Feb 02
3
publishing random effects from lme
Dear all,
Suppose I have a linear mixed-effects model (from the package nlme) with
nested random effects (see below); how would I present the results from
the random effects part in a publication?
Specifically, I?d like to know:
(1) What is the total variance of the random effects at each level?
(2) How can I test the significance of the variance components?
(3) Is there something like an
2006 Sep 11
1
summary(glm) for categorical variables
Dear list people
Suppose we have a data.frame where variables are categorical and the response is
categorical eg:
my.df=NULL
for(i in LETTERS[1:3]){my.df[[i]]=sample(letters, size=10)}
my.df=data.frame(my.df)
my.df$class=factor(rep(c("pos", "neg"), times=5))
my.glm=glm(class ~ ., data=my.df, family=binomial)
summary(my.glm)
....
Estimate Std. Error z
2006 Oct 29
0
Using predict.glm for classification
Dear R users,
I'm trying to understand how to derive the actual predictions (in terms of
class) using predict.glm. Consider this example:
mydf=data.frame(A=sample(rnorm(1000), size=1000, replace=T), B=sample(rnorm(5),
size=1000, replace=T), C=sample(rnorm(10), size=1000, replace=T),
class=sample(c("a", "b"), size=1000, replace=T))
mydf.glm=glm(class ~ .^2, data=mydf,
2003 Oct 29
1
I have a problem with the log2 function
Dear R users,
according the help(log), the function
log2(x) should give the natural logarithm of x.
I expect in case of x=2 to to get 0.6931, however, R gives me 1 as a result.
Similar, logb(2,2) gives 1 again.
I'm wondering if I have missed something ?
Yours
Frank
--
Frank Mattes, MD e-mail: f.mattes at ucl.ac.uk
Department of Virology fax 0044(0)207 8302854
Royal Free Hospital
2005 Oct 02
2
convering upper triangular matrix into vector
Hi
I have two symmetrical distance matrices and want to compute the correlation
coefficient between them (after turning them into vectors).
Is there a way of selecting only the upper triangular part of each matrix, then
convert this into a vector so I can compute the correlation?
Many Thanks
Eleni Rapsomaniki
2006 Sep 15
0
R: Grouping columns in a data frame based on the values of a column
Perhaps using 'ave' and 'cut':
df <- data.frame(x=runif(100, 0.1, 1), y=rnorm(100, 0.2, 0.6))
df$xcut<-cut(df$x, seq(0, 1, 0.1))
df$z<-ave(df$y, df$xcut)
df[order(df$x),]
Stefano
-----Messaggio originale-----
Da: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch]Per conto di
e.rapsomaniki at mail.cryst.bbk.ac.uk
Inviato: venerd? 15
2006 Sep 27
1
Any hot-deck imputation packages?
Hi
I found on google that there is an implementation of hot-deck imputation in
SAS:
http://ideas.repec.org/c/boc/bocode/s366901.html
Is there anything similar in R?
Many Thanks
Eleni Rapsomaniki
2005 Apr 11
1
extracting correlations from nlme
Hi,
I would like to know how (if) I can extract some of the information from
the summary of my nlme.
at present, I get a summary looking something like this:
> summary(fit.nlme)
Nonlinear mixed-effects model fit by maximum likelihood
Model: MLKYLD ~ W4(DIM, logA, B, C)
Data: ADHIS.x0
AIC BIC logLik
265314 265401.6 -132647
Random effects:
Formula: list(logA ~ 1 , B ~
2011 May 17
2
can not use plot.Predict {rms} reproduce figure 7.8 from Regression Modeling Strategies (http://biostat.mc.vanderbilt.edu/wiki/pub/Main/RmS/course2.pdf)
Dear R-users,
I am using R 2.13.0 and rms 3.3-0 , but can not reproduce figure 7.8 of the
handouts *Regression Modeling Strategies* (
http://biostat.mc.vanderbilt.edu/wiki/pub/Main/RmS/course2.pdf) by the
following code. Could any one help me figure out how to solve this?
setwd('C:/Rharrell')
require(rms)
load('data/counties.sav')
older <- counties$age6574 + counties$age75
2011 Mar 21
1
round, unique and factor
Survfit had a bug in some prior releases due to the use of both
unique(times) and table(times); I fixed it by rounding to 15 digits per
the manual page for as.character. Yes, I should ferret out all the
usages instead, but this was fast and it cured the user's problem.
The bug is back! A data set from a local colleage triggers it.
I can send the rda file to anyone who wishes.
The
2007 Nov 28
1
Histograms and Sturges rule
Dear All,
According to the Sturges rule, the number of classes of a histogram is
the closest integer to
1 + logb(n,base=2)
where n is the number of observations. The function hist(), by
default, uses the Sturges rule. However, the code
x <- 1:200
hist(x)
produces a histogram with 10 classes and not 9 classes as determined
by the Sturges rule. What am I missing?
Thanks in advance,
Paul
2006 Sep 15
1
Grouping columns in a data frame based on the values of a column
Dear R users,
This is a trivial question, there might even be an R function for it, but I have
to do it many times and wonder if there is an efficient for it.
Suppose we have a data frame like this:
d <- data.frame(x=sample(seq(0.1:1, by=0.01), size=100, replace=TRUE),
y=rnorm(100, 0.2, 0.6))
and want to have the average of y for a given interval of x, for example
mean(y)[0>x>0.1]. Is
2007 Sep 25
7
Who uses R?
Dear R users,
I have started work in a Statistics government department and I am trying to
convince my bosses to install R on our computers (I can't do proper stats in
Excel!!). They asked me to prove that this is a widely used software (and not
just another free-source, bug infected toy I found on the web!) by suggesting
other big organisations that use it. Are you aware of any reputable
2004 Jul 06
1
vectorizing sapply() code (Modified by Aaron J. Mackey)
[ Not sure why, but the first time I sent this it never seemed to go
through; apologies if you're seeing this twice ... ]
I have some fully functional code that I'm guessing can be done
better/quicker with some savvy R vector tricks; any help to make this
run a bit faster would be greatly appreciated; I'm particularly stuck
on how to calculate using "row-wise" vectors