Displaying 20 results from an estimated 900 matches similar to: "passing variable to formula environment"
2005 Oct 27
3
outer-question
Dear all,
This is a rather lengthy message, but I don't know what I made wrong in
my real example since the simple code works.
I have two variables a, b and a function f for which I would like to
calculate all possible combinations of the values of a and b.
If f is multiplication, I would simply do:
a <- 1:5
b <- 1:5
outer(a,b)
## A bit more complicated is this:
f <-
2005 Oct 27
3
outer-question
Dear all,
This is a rather lengthy message, but I don't know what I made wrong in
my real example since the simple code works.
I have two variables a, b and a function f for which I would like to
calculate all possible combinations of the values of a and b.
If f is multiplication, I would simply do:
a <- 1:5
b <- 1:5
outer(a,b)
## A bit more complicated is this:
f <-
2003 Nov 11
1
nlme-problem
Hi,
I have a problem with fitting a nonlinear mixed-effects model to my data.
I was able to fit quite simple exponential model but now I?m trying to fit
the following Gompertz model:
> gomp<-nlme(paino~b0+b1*exp(-exp(-b2*(daydeg.scale-b3))), data=group1,
fixed=b0+b1+b2+b3~1, start=c(b0=150, b1=3000, b2=0.6, b3=2500))
I?m getting the following error:
Error in chol((value + t(value))/2) :
2012 Nov 15
2
survreg & gompertz
Hi all,
Sorry if this has been answered already, but I couldn't find it in the
archives or general internet.
Is it possible to implement the gompertz distribution as
survreg.distribution to use with survreg of the survival library?
I haven't found anything and recent attempts from my side weren't
succefull so far.
I know that other packages like 'eha' and
2010 Feb 05
1
Using coxph with Gompertz-distributed survival data.
Dear list:
I am attempting to use what I thought would be a pretty straightforward practical application of Cox regression. I figure users of the survival package must have come across this problem before, so I would like to ask you how you dealt with it. I have set up an illustrative example and included it at the end of this post.
I took a sample of 100 data points from each of two populations
2012 Jul 01
1
significant difference between Gompertz hazard parameters?
Hello, all.
I have co-opted a number of functions that can be used to plot the
hazard/survival functions and associated density distribution for a Gompertz
mortality model, given known parameters. The Gompertz hazard model has been
shown to fit relatively well to the human adult lifespan. For example, if I
wanted to plot the hazard (i.e., mortality) functions:
pop1 <- function (t)
{
2013 May 14
1
Tamaño plots y calidad en grafico ggplot
Hola a tod en s,
bueno, un poco al hilo de un mensaje anterior, reformulo la pregunta y
pongo código completamente reproducible, a ver si hay más suerte.
Estoy con un informe y hay que hacer algunos gráficos con datos
diferentes con ggplot2, y hay que poner el mismo tamaño para todos
ellos.
El problema es que R cambia automáticamente el tamaño del área de
trazado y el margen en función de
2012 Jan 12
2
Function accepted by optim but not mle2 (?)
Dear Sir/ Madam,
I'm having trouble de-bugging the following - which works perfectly
well with optim or optimx - but not with mle2.
I'd be really grateful if someone could show me what is wrong. Many
thanks in advance. JSC:
gompertz<- function (x,t=data)
{
a3<-x[1]
b3<-x[2]
shift<-data[1]
h.t<-a3*exp(b3*(t-shift))
2007 Aug 04
2
multiple nls - next fit even after convergence problem
Hello R-gurus,
I'm trying to adjust different growth curves to a rather extensive dataset.
I wrote up a function to go through all of them, but am encountering a problem :
among the more than 1000 curves I have, obviously for some of them I encounter conversion problems.
I'd like for my function to keep going to the next curve and store the fact that for curve number X I had a convergence
2008 Nov 12
3
Fitting data to a sigmoidal curve
Hi-
I'm a biologist trying to figure out the growth rate of salamanders in
different ponds. I collected individuals from various populations at
different dates, and using the size and date collected, I want to figure out
the growth curve of each population. My question is: How do I fit my data to
a Gompertz function in R?
Thank you so much!
Sarah
--
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2011 Mar 22
2
[LLVMdev] Parallelization
Hi Duncan Sands,
As I have understood, GOMP and OpenMP provides support for parallelizing
program at source program level. But I am at the IR level. That is I am
trying to parallelize the IR code. This is the case of automatic
parallelization. The programmer writing the code does not have any idea of
parallelization going behind the hood.
So my question is instead of support at the source
2010 Nov 09
1
ggplot2: facet_grid with different vertical lines on each facet
Hello,
I am plotting many histograms together using facet_grid in ggplot2. However,
I want to then add a vertical line to each histogram, or facet, each of
which vertical lines are at different x-values.
The following example adds all vertical lines to each facet:
ggplot(data,aes(values)) + geom_histogram() + facet_grid(.~variable) +
geom_vline(xintercept=c(5,10,15))
How can I add a vertical
2005 Oct 31
1
[R] unvectorized option for outer()
> From: Thomas Lumley
>
> On Sun, 30 Oct 2005, Jonathan Rougier wrote:
>
> > I'm not sure about this. Perhaps I am a dinosaur, but my feeling is
> > that if people are writing functions in R that might be subject to
> > simple operations like outer products, then they ought to be writing
> > vectorised functions!
>
> I would agree. How about an
2009 Aug 10
2
ggplot: colours to geom_segments
Just as an exercise I am tying to add colours to a geom_segment command. I can get one colour but not a sequence of colours.
Can anyone suggest how I can get the green lines in the plot below to be different colours? I thought I could use a palatte of colours but that did not seem to work.
Thanks
=========================================================================
library(ggplot2)
xx
2011 Mar 22
0
[LLVMdev] Parallelization
On Tue, Mar 22, 2011 at 1:36 PM, Gokul Ramaswamy <gokulhcramaswamy at gmail.com
> wrote:
> Hi Duncan Sands,
>
> As I have understood, GOMP and OpenMP provides support for
> parallelizing program at source program level. But I am at the IR level.
> That is I am trying to parallelize the IR code. This is the case of
> automatic parallelization. The programmer writing the
2011 Sep 08
4
[LLVMdev] multi-threading in llvm
Hi,
I want to execute the iterations of a loop in parallel, by inserting calls either to pthreads or to the gomp library at the LLVM IR level. As a first step, I inserted an omp pragma in a C file and compiled it with llvm-gcc to check the generated LLVM code. If I understand correctly, to parallelize the loop in LLVM IR, I have to separate the loop in a new function, put all required parameters
2009 Mar 06
1
fitting a gompertz model through the origin using nls
Dear all!
I tried to fit Gompertz growth models to describe cummulative germination rates
using nls. I used the following code:
germ.model<-nls(percent.germ~a*exp(-b*exp(-k*day)),data=tab,start=list(a=100,b=10,k=0.5))
My problem is that I want that the fitted model goes through the origin, since
germination cannot start before the experiment was started, and y-max should be
100.
Does anyone
2011 Mar 22
2
[LLVMdev] Parallelization
On 03/22/2011 01:56 PM, Reid Kleckner wrote:
> On Tue, Mar 22, 2011 at 1:36 PM, Gokul Ramaswamy
> <gokulhcramaswamy at gmail.com <mailto:gokulhcramaswamy at gmail.com>> wrote:
>
> Hi Duncan Sands,
>
> As I have understood, GOMP and OpenMP provides support for
> parallelizing program at source program level. But I am at the IR
> level. That
2011 Sep 12
0
[LLVMdev] multi-threading in llvm
Hi Alexandra,
I don't know much, maybe this topic should be bridged with polly-dev
(adding it to CC) to bring it more attention.
Indeed, polly uses ScopPass, that creates serious limitations in
compatibility with other passes. To my understanding, scops are used
because ISL loop analysis tool uses scops. In fact, just for handling
OpenMP directives scops are not required, unless one need to
2008 Feb 06
6
[LLVMdev] strange visibility error when compiling llvm-gcc-4.2
On Feb 6, 2008, at 5:18 AM, Duncan Sands wrote:
> Hi,
>
>> if /bin/sh ./libtool --mode=compile /s/llvm/obj.gcc42/./gcc/xgcc -B/
>> s/llvm/obj.gcc42/./gcc/ -B/usr/local/i686-pc-linux-gnu/bin/ -B/usr/
>> local/i686-pc-linux-gnu/lib/ -isystem /usr/local/i686-pc-linux-gnu/
>> include -isystem /usr/local/i686-pc-linux-gnu/sys-include -
>> DHAVE_CONFIG_H -I.