Displaying 20 results from an estimated 1000 matches similar to: "Estimate region of highest probabilty density"
2008 Jun 25
1
help_transformation
heya,
i am fitting linear mixed effect model to a response Y. Y shows an s-shaped distribution when using QQ-plots (some zero values and some very high values). hence, which transformation should i apply that Y follows a normal distribution? any r-function/package available to do this?
thanks for any hint,
regards,
lukas
???
Lukas Indermaur, PhD student
eawag / Swiss Federal Institute of
2007 Feb 20
1
testing slopes
Hello
Instead of testing against 0 i would like to test regression slopes against -1. Any idea if there's an R script (package?) available.
Thanks for any hint.
Cheers
Lukas
???
Lukas Indermaur, PhD student
eawag / Swiss Federal Institute of Aquatic Science and Technology
ECO - Department of Aquatic Ecology
?berlandstrasse 133
CH-8600 D?bendorf
Switzerland
Phone: +41 (0) 71 220
2007 Feb 27
4
fitting of all possible models
Hi,
Fitting all possible models (GLM) with 10 predictors will result in loads of (2^10 - 1) models. I want to do that in order to get the importance of variables (having an unbalanced variable design) by summing the up the AIC-weights of models including the same variable, for every variable separately. It's time consuming and annoying to define all possible models by hand.
Is there a
2007 Feb 28
1
bootstrap
Hi,
I would like to evaluate the frequency of the variables within the best selected model by AIC among a set of 12 competing models (I fit them with GLM) with a bootstrap procedure to get unbiased results. So I would ike to do the ranking of the 12-model-set 10'000 times separately and calculate the frequency of variables of the 10'000 best ranked models. I wrote a script doing the model
2007 Jan 11
3
batch job GLM calculations
Hello
I want to batch job the calculation of many GLM-models, extract some values and store them in a file. Almost everything in the script below works (read file, extract values and write them to file) except I fail in indexing the GLM with the modelstructure it should run. Running GLM's conventionally is no problem.
Conventionally a GLM is calculated as:
2007 Aug 10
1
kde2d error message
Hello!
I am trying to do a smooth with the kde2d function, and I'm getting an error
message about NAs. Does anyone have any suggestions? Does this function
not do well with NAs in general?
fit <- kde2d(X, Y, n=100,lims=c(range(X),range(Y)))
Error in if (from == to || length.out < 2) by <- 1 :
missing value where TRUE/FALSE needed
Thanks in advance!!
Jen
[[alternative
2012 Apr 18
1
ggplot2 stat_density2d issue.
Hello,
I'd be very grateful for help with some ggplot2's stat_density2d issues.
First issue is with data limits. xlim() and ylim() doesn't seem to
work; instead, estimates (and plotting) seems to be constrained to
range(x), range(y) no matter what i do. The documentation says i can
pass in kde2d's parameters to ... but pussing kde2d's "lims" parameter
achieves
2006 Dec 01
1
mixed effects model and r-squared
Heya
I am fitting linear mixed effects model in R and want to assess the model fit (with Animal number as random factor; repeated measures for Animals):
ts.model <- lme(LOG_FOC_MW ~ R_DN_SUM + ANIMAL + SEX+ YY, data = t.data, random = ~ 1 | ANIMAL, correlation=corCAR1(0.2, form = ~1 | ANIMAL ), method='ML', na.action=na.omit)).
Is there a possability to easly compute an
2008 Jun 25
1
confidence bounds using contour plot
Hello
I'm trying to calculate 2d confindence bounds into a scatterplot using the
function "kde2d" (package MASS) and a contour plot.
I found a similar post providing a solution - unfortunatly I do not realy
understand which data I have to use to calculated the named "quantile":
Post URL: http://tolstoy.newcastle.edu.au/R/help/03b/5384.html
> (...)
>
>> Is
2006 Jan 19
2
function kde2d
Good evening,
I am Marta Colombo, student at Milan's Politecnico.
Thank you very much for your kindness, this mailing list is really useful.
I am using the function kde2d for two-dimensional kernel density estimation and I'd like to know something more about this kind of density estimator. In particular I'd like to know: what bandwidth is used ?
Thank you in advance for your attention
2000 Nov 16
2
newbee question
Dear All
Where can I lookup good methods to compute
p from q=bin(m,n)p^n*(1-p)^(m-n) such that
q<=alfa, alfa small. Are there such libs,
code and source in R?
Best Regards
--
Jan Burse SIAM, EAWAG
Scheuchzerstr. 67 ?berlandstr. 133
8006 Z?rich 8600 D?bendorf
tel: +41-1-364 17 66 tel: +41-1-823 55 34
2008 Jan 16
1
Probability weights with density estimation
I am a physician examining an NHANES dataset available at the NCHS
website:
http://www.cdc.gov/nchs/about/major/nhanes/nhanes2005-2006/demo_d.xpt
http://www.cdc.gov/nchs/about/major/nhanes/nhanes2005-2006/hdl_d.xpt
http://www.cdc.gov/nchs/about/major/nhanes/nhanes2005-2006/tchol_d.xpt
Thank you to the R authors and the foreign package authors in
particular. Importing from the SAS export
2007 Nov 26
2
2d Joint Density Plot
Hi all,
I'm fairly new to R, so I'm still trying to feel out what is available to
me. I would like to be able to plot joint density in a two dimensional plot
where density is indicated by color or darkness gradients, like a 2d color
coded topographic map. Ideally, the output would be something I could then
plot other points or lines on.
Currently, I'm calculating joint density with
2017 Nov 18
0
Using cforest on a hierarchically structured dataset
Hi,
I am facing a hierarchically structured dataset, and I am not sure of
the right way to analyses it with cforest, if their is one.
- - BACKGROUND & PROBLEM
We are analyzing the behavior of some social birds facing different
temperature conditions.
The behaviors of the birds were recorder during many sessions of 2 hours.
Conditional RF (cforest) are quite useful for this analysis
2006 May 11
1
Conditional contour plots for estimated density functions using Lattice
Does anybody here have a suggestion for a clever way of creating contour
plots for estimated bivariate density functions conditional on a factor?
The contourplot function in the 'lattice' package only accepts data that
are on the form 'z ~ x * y', not on the form 'x,y' or 'y~x'; otherwise I
could probably have used the panel function to do the needed conversion.
2009 Mar 08
1
Summary of data.frame according to colnames and grouping factor
A dataframe holds 3 vars, each checked true or false (1, 0). Another
var holds the grouping, r and s:
### start:example
set.seed(20)
d <- data.frame(sample(c(0, 1), 20, replace=T), sample(c(0, 1), 20,
replace=T), sample(c(0, 1), 20, replace=T))
names(d) <- c("A", "B", "C")
e <- rep(c("r", "s"), 10)
### end:example
How do I get the
2009 Mar 11
3
chisq.test: decreasing p-value
A Likert scale may have produced counts of answers per category.
According to theory I may expect equality over the categories. A
statistical test shall reveal the actual equality in my sample.
When applying a chi square test with increasing number of repetitions
(simulate.p.value) over a fixed sample, the p-value decreases
dramatically (looks as if converge to zero).
(1) Why?
(2) (If
2009 Nov 22
3
Define return values of a function
I have created a function to do something:
i <- factor(sample(c("A", "B", "C", NA), 793, rep=T, prob=c(8, 7, 5,
1)))
k <- factor(sample(c("X", "Y", "Z", NA), 793, rep=T, prob=c(12, 7, 9,
1)))
mytable <- function(x){
xtb <- x
btx <- x
# do more with x, not relevant here
cat("The table has been created,
2010 Feb 15
4
density estimates for fixed points
Problem:
Based on a n x 2 data matrix i want a kernel estimate of the bivariate
density. However, i also wish to specify wich points the density should be
calculated at.
I can offcourse just write the full kernel density estimate as a R-code, but
surely there must already exist some package for this operation?
The package density(), seems to create a new matrix (depending on n), where
the
2009 Mar 07
2
Recode factor into binary factor-level vars
How to I "recode" a factor into a binary data frame according to the
factor levels:
### example:start
set.seed(20)
l <- sample(rep.int(c("locA", "locB", "locC", "locD"), 100), 10,
replace=T)
# [1] "locD" "locD" "locD" "locD" "locB" "locA" "locA" "locA"