Displaying 12 results from an estimated 12 matches similar to: "Estimating LC50 from a Weibull distribution"
2018 Feb 22
1
Calculate LC50
Dear All: good morning
I need helps with the calculation of the *LC50* from the data below
x<-c(0,0.3,0.7,1,4,10)
y<-c(100,86,65,51.3,19.2,7.4)
yxreg<-lm(y~x)
any help will be highly appreciated.
with many thanks
abou
______________________
*AbouEl-Makarim Aboueissa, PhD*
*Professor of Statistics*
*Department of Mathematics and Statistics*
*University of Southern Maine*
2006 Oct 06
1
glm and plot.effects
Dear R-helpers,
I don't see a difference between the following two plots of effect
objects, which I understand should be different. What am I missing?
require(doBy)
require(effects)
data(budworm)
m1 <- glm(ndead/20 ~ sex + log(dose), data=budworm, weight=ntotal,
family=binomial)
m1.eff <- all.effects(m1)
plot(m1.eff, rescale.axis = FALSE, selection = 2, main = 'rescale =
2010 Nov 22
2
Probit Analysis: Confidence Interval for the LD50 using Fieller's and Heterogeneity (UNCLASSIFIED)
Classification: UNCLASSIFIED
Caveats: NONE
A similar question has been posted in the past but never answered. My
question is this: for probit analysis, how do you program a 95%
confidence interval for the LD50 (or LC50, ec50, etc.), including a
heterogeneity factor as written about in "Probit Analysis" by
Finney(1971)? The heterogeneity factor comes into play through the
chi-squared
2012 Apr 02
7
Calculating NOEL using R and logistic regression - Toxicology
Hello, I used the glm function in R to fit a dose-response relationship and
then have been using dose.p to calculate the LC50, however I would like to
calculate the NOEL (no observed effect level), ie the lowest dose above
which responses start occurring. Does anyone know how to do this?
[[alternative HTML version deleted]]
2012 Apr 03
0
Off Topic: Re: Calculating NOEL using R and logistic regression - Toxicology
Below.
-- Bert
On Tue, Apr 3, 2012 at 1:47 PM, Danielle Duncan <dlduncan2 at alaska.edu> wrote:
> Thanks for the response, I should have clarified that the NOEL is the
> smallest dose above which there is a statistically significant effect.
>
This is not a scientifically meaningful nor defensible definition as
it is stochastic, depends on the test used, design, level chosen, etc.
2008 Nov 03
3
[rsync -avz] total size/disk usage difference between source and destination
Hi folks
We migrated storage from local disk to SAN with:
# rsync -avz /mnt/lvol00045/* /lvol00045
Why there is a difference in size? How to explain this? Do we have
inconsistency? What we did wrong?
[...]
/dev/mapper/vg01-lvol00045_old
10321208 3930336 6286016 39% /mnt/lvol00045
[...]
/dev/mapper/vg01-lvol00045
10321208 3163852 6633068 33%
2009 Oct 25
1
Packages in 5.4 older than 5.3 updates, and no 5.4 updates available?
I've been checking the updates tree for 5.4 and notice that they're empty.
I checked 4 or 5 different servers and got the same results. This is,
in my experience, unusual; there's typically patches for the new release
from day one. But it could be that the 5.4 DVD is up to date.
So I checked one of my machines and what updates it would need against
5.3 vs those that it would need to
2012 Feb 03
1
A question on Unit Root Test using "urca" toolbox
Hello,
I have a question on unit root test with urca toolbox.
First, to run a unit root test with lags selected by BIC, I type:
> CPILD4UR<-ur.df(x1$CPILD4[5:nr1], type ="drift", lags=12, selectlags ="BIC")
> summary(CPILD4UR)
The results indicate that the optimal lags selected by BIC is 4.
Then I run the same unit root test with drift and 4 lags:
2014 Sep 01
1
Correlation Matrix with a Covariate
R Help -
I'm trying to run a correlation matrix with a covariate of "age" and will
at some point will also want to covary other variables concurrently.
I'm using the "psych" package and have tried other methods such as writing
a loop to extract semi-partial correlations, but it does not seem to be
working. How can I accomplish this?
library(psych)
> set.cor(y =
2011 Aug 16
7
left menu for Fedena Project
i wanna add left menu in the http://demo.projectfedena.org/
login:admin password:admin123 as there is no left menu in that i
thought of adding a left menu. can any one tell how to do that with
ROR.
--
You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group.
To post to this group, send email to
2013 May 15
4
series financieras
Buenos dias,
Tengo la siguiente duda.
Desde una hoja de calculo .xls me descargo un fichero en r as.matrix.
Time VAR_2 VAR_3 VAR_4........ VAR_N
Fechas(n) Precios Precios Precios Precios
Fechas (n-1)
¿como puedo hacer para graficar de forma ordenada (fechas) cada uno del vector columnas (son precios de activos)?
[[alternative HTML
2010 Nov 24
0
4. Rexcel (Luis Felipe Parra)-how to run a code from excel
Hi Louis,
It's simple to run a r script from the excel spreadsheet.
Just write your code, source("C:\\Quantil
Aplicativos\\Genercauca\\BackwardSelectionNC.r"), into a cell of a
workingsheet. Then right-click the cell and select "run code" in the pop-up
menu.
Hope this will help you.
Best,
Bernard
-----????-----
???: r-help-bounces at r-project.org [mailto:r-help-bounces