Displaying 20 results from an estimated 900 matches similar to: "Replicated goodness-of-fit test"
2001 Mar 22
0
[Fwd: FW: Biostats text/software]
[This was filtered (looking like spam)
and manually approved by your list maintainer, MM ]
EvolDir wrote:
> Colleagues,
>
> A few days ago I posted a message inquiring what folks were using for
> teaching biostats. I received a stunning 38 replies offering various
> opinions, some quite surprising, along with links to web pages, pointers for
> coverage, commentaries on
1999 Apr 09
2
KS test from ctest package
This question is mainly aimed at Kurt Hornik as author of the ctest package,
but I'm cc'ing it to r-help as I suspect there will be other valuable
opinions out there.
I have been attempting 2 sample Kolmogorov-Smirnov tests using the ks.test
function from the ctest package (ctest v.0.9-15, R v.0.63.3 win32). I am
comparing fish length-frequency distributions. My main reference for the
2001 Sep 20
0
G-test : log-likelihood ratio test
I've written a g.test() aka log-likelihood ratio test function for my
opwn use. It's something I've seen requested (and looked to find
myself) on this list a few times.
It has the same basic syntax as chisq.test().
It does both goodness of fit tests and tests of independence.
Yates' and Williams' corrections are implemented.
I've put some examples from Sokal & Rohlf
2007 Dec 20
1
hierarchical linear models, mixed models and lme
Dear R-users,
I am trying to analyse the data of the box 10.5 in the Biometry from
Sokal and Rohlf (2001) using R. This is a three-level nested anova with
equal sample size : 3 different treatments are compared ; 2 rats (coded
1 or 2) / treatment are studied ; 3 preparations (coded 1, 2 or 3) /
rats are available ; 2 readings of the glycogen content / preparations
are realised. Treatment is
2007 Nov 22
3
anova planned comparisons/contrasts
Hi,
I'm trying to figure out how anova works in R by translating the
examples in Sokal And Rohlf's (1995 3rd edition) Biometry. I've hit a
snag with planned comparisons, their box 9.4 and section 9.6. It's a
basic anova design:
treatment <- factor(rep(c("control", "glucose", "fructose",
"gluc+fruct",
2000 Sep 21
2
qqnorm(), is it "backwards"?
Hello R friends,
I'm wondering why I get funny qqnorm() results. It seems that they should
all be reflected in the normal qqline().
For instance: if I qqnorm() bimodal or uniform data I get a sigmoidal in
which the qqnorm() points lie above the qqline() at -ve theoretical
quantiles, and the qqnorm() points lie below the qqline() at +ve
theoretical quantiles. Yet I expect such platykurtic
2005 Jul 13
1
Boxcox transformation / homogeneity of variances
Dear r-helpers,
Prior to analysis of variance, I ran the Boxcox function (MASS library) to
find the best power transformation of my data. However, reading the Boxcox
help file, I cannot figure out if this function (through its associated
log-likelihood function) corrects for * normality only * or if it also
induces * homogeneity of variances *. I found in Biometry (Sokal and Rohlf,
p. 419)
2002 Mar 26
3
ks.test - continuous vs discrete
I frequently want to test for differences between animal size frequency
distributions. The obvious test (I think) to use is the Kolmogorov-Smirnov
two sample test (provided in R as the function ks.test in package ctest).
The KS test is for continuous variables and this obviously includes length,
weight etc. However, limitations in measuring (e.g length to the nearest
cm/mm, weight to the nearest
2003 Sep 03
0
Re: normal distribution in samples of soil organisms.
Hi,
You didn't specify the satistical model you are intereted in, I will
suppose it is something like:
#Organims ~ Landscape + Soil + Depth + Species
I suppose you have a table of with something like...
Spec Lands Soil Depth #Organisms
A 1 1 1 10
A 1 2 1 2
B 1 1 1 0
B 2 2 2 2
... etc,
Normally, the count of organisms in soil samples follows a posisson
distribution, not a normal one.
2003 Mar 21
2
Trying to make a nested lme analysis
Hi,
I''m trying to understand the lme output and procedure.
I''m using the Crawley''s book.
I''m try to analyse the rats example take from Sokal and Rohlf (1995).
I make a nested analysis using aov following the book.
> summary(rats)
Glycogen Treatment Rat Liver
Min. :125.0 Min. :1 Min. :1.0 Min. :1
1st Qu.:135.8
2002 Apr 15
1
nested anova not giving expected results
Hello all. This may be a trivially simple question to answer, but I'm a little
bit stumped with respect to the calculation of the F statistics in nested
anovas in R. If I understand correctly, the F statistic for the
among-subgroups but within groups hypothesis is calculated as
MS_subgroups/MS_error, while the F statistic for the factor is calculated as
MS_factor/MS_subgroups (I'm
2012 Feb 06
1
multiple comparisons in nested design
Dear professors and collegues
I need to perform a analysis of dates from a nested experimental design.
From
"Bioestatical Analysis" of Zar
"Bimetry of Sokal" & Rohlf
"Design and Analysis of Experiments" of Montgomery
I have:
Sum (mean(x)_i - mean(x)_T)2 / (a-1) -> var(epsilon) + n sigma2_B + n b
(sum alfa_i)2 / (a-1)
Sum (mean(x)_ij - mean(x)_i)2 /
2006 Aug 30
1
lmer applied to a wellknown (?) example
Dear all,
During my pre-R era I tried (yes, tried) to understand mixed models by
working through the 'rat example' in Sokal and Rohlfs Biometry (2000)
3ed p 288-292. The same example was later used by Crawley (2002) in his
Statistical Computing p 363-373 and I have seen the same data being used
elsewhere in the litterature.
Because this example is so thoroughly described, I thought
2006 Jul 11
1
test regression against given slope for reduced major axis regression (RMA)
Hi,
for testing if the slope of experimental data differs from a
given slope I'm using the function
"test_regression_against_slope" (see below).
I am now confronted with the problem that I have data which
requires a modelII regression (also called reduced major axes
regression (RMA) or geometric mean regression). For this I use
the function "modelII" (see below).
What
2006 Nov 03
5
ANOVA in Randomized-complete blocks design
Dear all,
I am trying to repeat an example from Sokal and Rohlfs "Biometry" --
Box 11.4, example of a randomized-complete-blocks experiment.
The data is fairly simple:
series genotype weight
1 pp 0.958
1 pb 0.985
1 bb 0.925
2 pp 0.971
2 pb 1.051
2 bb 0.952
3 pp 0.927
3 pb 0.891
3 bb 0.892
4
2012 Aug 06
1
cannot find function "simpleRDA2"
Hi,
I am trying to run the command "forward.sel.par," however I receive
the error message: "Error: could not find function 'simpleRDA2'." I
have the vegan library loaded. The documentation on "varpart" has not
helped me to understand why I cannot call this function. Maybe I am
missing something obvious because I am still an 'R' novice.
Below is a
2004 Feb 19
1
Comparing two regression slopes
I would suggest the method of Sokal and Rholf (1995) S. 498, using the F
test.
Below I repeat the analysis by Spencer Graves:
Spencer:
> df1 <- data.frame(x=1:3, y=1:3+rnorm(3))
> df2 <- data.frame(x=1:3, y=1:3+rnorm(3))
> fit1 <- lm(y~x, df1)
> s1 <- summary(fit1)$coefficients
> fit2 <- lm(y~x, df2)
> s2 <- summary(fit2)$coefficients
> db <-
2011 Mar 29
7
Error en cor, too many elements specified
Hola, tengo una serie de datos datExpr, al usar cor() :
cor(datExpr ,method = "pearson", use ="pairwise.complete.obs")
me da el siguiente error
allocMatrix: too many elements specified
Trate con "complete.obs", "na.or.complete", y el resto de las opciones para "use", pero siempre me da algun error.
¿Alguna idea de como puedo hacer que cor() lea
2009 Oct 29
2
similarity measure for binary data
I am doing hierarchical clustering with cluster package. I couldnot find similarity measures like matching coefficient, Jaccard coefficient and sokal and sneath. Could anyone please tell package with similarity measures for binary data?
kind regards,
Ms.Karunambigai M
PhD Scholar
Dept. of Biostatistics
NIMHANS
Bangalore
India
From cricket scores to your friends. Try the Yahoo! India
2004 Apr 02
0
First approach to Asterisk - need help
Hello,
We are trying to migrate from an old application based on VOS to some
linux based telephony server. We are investigating bayonne and asterisk,
and we still don't know what is the best option for us.
One of the limitations is our old hardware, we have in stock some old
Dialogic boards. Does asterisk work with such boards? The other
important limitation is that the application needs to