Displaying 20 results from an estimated 3000 matches similar to: "recoding large number of categories (select in SAS)"
2006 Sep 13
1
reshaping a dataset
Hi,
I'm trying to move to R the last few data handling routines I was
performing in SAS.
I'm working on stomach content data. In the simplified example I
provide below, there are variables describing the origin of each prey
item (nbpc is a ship number, each ship may have been used on
different trips, each trip has stations, and individual fish (tagno)
can be caught at each
2010 Feb 15
1
GAM for non-integer proportions
Dear list,
I´m using the mgcv package to model the proportion by weight of certain prey
on the stomach content of a predator. This proportion is the ratio of two
weights (prey weight over stomach weight), and ranges between 0 and 1. The
variance is low when proportion is close to 0 and 1, and higher at
intermediate values.
It seems that the best way to go is to model this using the
2011 Mar 10
2
Not sure how to handle hazard in my survival model
Hi R experts :)
I'm trying to carry out a survival model on my data, but I am unsure of
whether it's appropriate or if I should do something specific in regards to
hazard.
My data is time to death by predator where I have 8 prey and one predator in
the setting. This means that two prey can't possibly die at the same time
and I can't quite get my head around how to include this in
2007 Feb 25
1
nested design in lme, need help with specifying model
Hi,
I wonder if anyone can help me with specifying a right model for my analysis. I am a beginner to lme methods and though have spent already many hours studying from various books an on-line helps, I was unfortunately not able to find a solution to my problem on my own.
Data structure:
I studied escape behavior of three species of a prey to a predator. The prey specimens (many) were in a
2010 Dec 11
2
Predator Prey Models
Dear R-users,
I am currently modifying a previously developed predator prey model and
was curious if there was a way to add in a disturbance to the model (let's
say at time t=100). The disturbance can be the introduction of 40 prey
(N=40) and 10 predators (Pred = 10). I would like to see my model go from a
state of equilibrium (up to t = 99), show this disturbance (at t = 100) and
then
2007 Dec 10
1
Multiple Reponse CART Analysis
Dear R friends-
I'm attempting to generate a regression tree with one gradient predictor and multiple responses, trying to test if change in size (turtle.data$Clength) acts as a single predictor of ten multiple diet taxa abundances (prey.data) Neither rpart or mvpart seem to allow me to do multiple responses. (Or if they can, I'm not using the functions properly.)
> library(rpart)
2008 May 26
4
Prey and OpenGL
I have installed Prey onto my pc running PCLinuxOS
following the instructions in
http://frankscorner.org/index.php?p=prey
or
http://appdb.winehq.org/objectManager.php?sClass=application&iId=3465
and tried running it. I then found I needed the nocd patch, which I downloaded and applied.
I then tried cd to the app folder, then wine prey.exe with the following result:
Prey 1.0.103 win-x86 Jun 10
2006 May 01
1
xyplot: trouble changing graphics settings
Hi
I am struggling with the correct code syntax to generate xyplots that are
different from the default graphics option.
This is simplified version of my data:
site size dnaconc prey
A 44 22.6 1
A 47 18.2 1
B 38 25.6 0
B 47 20.5 1
C 45 30.5 0
C 32 18.5 0
D 45 15.0 1
D 22 20.1 0
So I am using xyplot(dnaconc~size|site,data=bug,groups=prey) to generate
4 panels (one for each site).
My
2010 Apr 28
1
NLS "Singular Gradient" Error
Hello,
I am trying to model a type II functional response of number of prey eaten
(Ne) against number supplied (No) with a non-linear least squares regression
(nls). I am using a modification of Holling's (1959) disc equation to
account for non-replacement of prey;
Ne=No{1-exp[a(bNe-T)]}
where a is the attack rate, b is the handling time, and T is the
experimental period.
My script is as
2008 May 29
1
In fact this is a Stats question, but... "The return."
*Thanks* all those who took the time to help me (even if the
"question" was not related to - the use of - R).
Now I think I can soundly make my point w/ the referee (can I use your
replies? If so I intend to properly cite its use?!?).
Regards, Eduardo Esteves
ps - Sorry for not explaining the "biological details" of my posting:
RNA/DNA is the ratio of RNA content to
2008 Dec 10
1
subset point data set by distance ranges
Greetings
I'm using R 2.8 with recent (last month) versions of the packages I need to
use at present.
I'm interested in examining hierarchical spatio-temporal patterns in a data
set. The data consist of 94 points (X, Y, UTM coordinates) at which catch
rates for a fish were recorded and there are also estimates of prey
available for these fish at the same locations.
2011 Feb 03
1
boostrap an nls regression
Hello there
I have the following model based on the hollings disc equation for the type
II functional response for 2 data sets:
nls(eaten~(a*suppl)/(1+a*h*suppl)
where eaten is the number of prey eaten by a predator and suppl is the
number of prey initially supplied to the same predator.
I have parameter estimates of 'a' and 'h' for the two populations studied
and would like
2008 Jun 27
4
Recoding
Hi!
Given a vector (or a factor within a df),i.e. v1 <- c(1,1,1,2,3,4,1,10,3)
and a dictionary
cbind(c(1,2,3),c(1001,1002,1003))
is there a function (on the same line than recode() in car)
to get v2 as c(1001,1001,1001,1002,1003,4,1001,10,1003) ?
I'm using myself a function based on match() since
long ago (I think that thanks to advice by Prof. B. Ripley),
but would like to know if there
2006 Sep 18
2
merge gives me too many rows
Hi,
I am using merge to add some variables to an existing dataframe. I
use the option "all.x=F" so that my final dataframe will only have as
many rows as the first file I name in the call to merge.
With a large dataframe using a lot of "by" variables, the number of
rows of the merged dataframe increases from 177325 to 179690:
>dim(test)
[1] 177325 9
>
2008 Mar 24
2
[LLVMdev] Potential breakage in llvm-gcc's ./configure
Am Montag, den 24.03.2008, 12:06 -0700 schrieb Tanya M. Lattner:
> > This is close to a showstopper for integrating an llvm-gcc bootstrap
> > into the nightly tester. The llvm-gcc ./configure needs to be called
> > very differently from the llvm ./configure, and keeping two sets of
> > options is Not Worth The Trouble, at least IMHO.
>
> So you didn't like the
2005 Jan 06
6
"labels" attached to variable names
Hi,
Can we attach a more descriptive "label" (I may use the wrong
terminology, which would explain why I found nothing on the FAQ) to
variable names, and later have an easy way to switch to these labels in
plots? I fear this is not possible and one must enter this by hand as
ylab and xlab when making plots.
Thanks in advance,
Denis Chabot
2008 May 29
2
In fact this is a Stats question, but...
Dear All,
I'me having (much) trouble understanding why it happened and answering
a referee's comment to part of a submitted manuscript. I've tried to
google for help but... I'm really confident that although this is a
R-Help list someone can help me!
I used R to do an ANCOVA w/ RNA/DNA as the dep var, sl as the indep
var and gut (a factor w/ levels: prey and empty) as the
2007 Jul 03
2
[LLVMdev] "bytecode" --> "bitcode"
I did this short experiment:
ggreif at my [!297] cd /home/ggreif/llvm
ggreif at my [!298] find . -name "*.cpp" | xargs grep bytecode | wc -l
143
I guess these are a quick prey for perl's in-place replace.
But wait! There are more:
ggreif at my [!299] find . -name "*.cpp" | xargs grep -i bytecode | wc -l
291
probably all of the rest is "Bytecode"
2002 Jul 30
1
Security Concern
I've got a problem regarding Win2K security on a Samba 2.2.3a domain.
We've got an issue where anyone in the same domain can browse another
users' C$.
That's bad...bad bad bad. Any PC with the default share (C$) is easy prey.
Is there a way to prevent this other than removing the share manually from
each and every PC?
Any thoughts would be appreciated.
Al Moote
2008 Feb 13
1
Is there a simple way to use one-way ANOVA comparing the means of groups?
Dear all,
I have finally managed to get a "Analysis of Variance Table":
Response: LogHand
Df Sum Sq Mean Sq F value Pr(>F)
Prey 3 5.3125 1.7708 20.672 2.066e-11 ***
Residuals 164 14.0488 0.0857
I want to compare the means of the four different groups, and see if
there is a difference. I searched for help,