Displaying 20 results from an estimated 400 matches similar to: "Test for multiple contrasts?"
2005 Mar 01
3
Anova with Scheffe Tests
Hi R-people,
I am wanting to run Factorial ANOVA followed by Scheffe tests on some spatial subjective data. I'm comparing X-Y independent coordinates against x-y dependent coordinates. There are only four independent spatial coordinates that form a square.
I am wondering whether I am doing the right thing, because there doesn't seem to be a simple way of doing this. I have attempted to
2018 Mar 15
0
cubic complete Scheffe mixture models
Hello everyone
I'm trying to use Scheffe's complete cubic model (mixture design).
In the bibliographies, they indicate that the term is of the type: A * B
* (A-B).
But I see that trying to adjust the three cubic terms results in
singularities.
I know this implies not having the inverse matrix:
solve (t (X)% *% X) does not exist.
The bibliographies show all three cubic terms.
So my
2001 Sep 27
1
list of all objects - just being curious
Hello all,
to obtain a list of all objects in all search paths, I've found the
following to work:
> biglist <- sapply(1:length(search()), objects)
This more obvious one, however, does not work:
> biglist <- sapply(search(), objects)
Error in pos.to.env(pos) : invalid argument
Still, search() gives
[1] ".GlobalEnv" "package:ctest" "Autoloads"
2000 Jun 22
0
Re: [R] R 1.1 congrat; undocumented behaviour of recordPlot (PR#578)
I think this is pretty certainly a bug, so I'm cc'ing this to r-bugs.
-p
Kaspar Pflugshaupt <pflugshaupt@geobot.umnw.ethz.ch> writes:
> Hello,
>
> first, I'd like to congratulate the core team to the new R version 1.1. I
> think it's a great update, with glimpses into an even greater future
> (tcltk!).
>
> While playing around with the new functions
2001 Nov 09
0
eqscplot() in library MASS: fails when given only one point (PR#1164)
This is not a bug. There is no way one can scale the plot axes equally
when no indication has been given of the scaling expected for either!
It has always seemd to be that plot(x=1, y=1) shoul dnot work: it
has not supplied enough information!
On Thu, 8 Nov 2001 pflugshaupt@geobot.umnw.ethz.ch wrote:
> I found the following in eqscplot, library MASS:
>
>
> When given just one
2002 Apr 04
1
html documentation bug in: help(par), 'las'
Currently (R-1.4.1 as well as R-devel, according to
http://stat.ethz.ch/R-alpha/R-devel/library/base/html/par.html), the html
version of help(par) shows
[...]
lab
A numerical vector of the form c(x, y, len) which modifies the way that
axes are annotated. The values of x and y give the (approximate) number
of tickmarks on the x and y axes and len specifies the label size. The
default
2001 Nov 08
0
eqscplot() in library MASS: fails when given only one point (PR#1162)
I found the following in eqscplot, library MASS:
When given just one point, it fails:
> eqscplot(x=1, y=1)
Error in plot.window(xlim, ylim, log, asp, ...) :
need finite xlim values
After inserting browser() just before the last line in eqscplot() (in which
plot() gets called), I found the following:
> eqscplot(x=1, y=1)
Called from: eqscplot(x = 1, y = 1)
Browse[1]> xlim
[1] NaN
2000 Oct 21
1
scale() and NA values
Hello,
I've a question concerning the behaviour of the "scale" function in the base
package. I'm using R 1.1.1 on Windows 95.
If I take a matrix with NA values, such as
> tm <- matrix(c(2,1,0,1,0,NA,NA,NA,0), nrow=3)
> tm
[,1] [,2] [,3]
[1,] 2 1 NA
[2,] 1 0 NA
[3,] 0 NA 0
and scale it, the columns containing NAs come out all NA:
>
2000 May 09
1
Type III Sums of Squares?
Hello,
I'd like to propose an extension to the function summary.aov.
In Splus (2000, I don't know about other versions), summary.aov allows a
parameter ssType to be set to 1 or 3 (defaults to 1) to choose the type of
Sums of Squares.
I know I can get Type III SS in R with drop1(model), but including the
functionality into summary.aov would, in my opinion,
- yield a more usable table
2002 Feb 04
1
Installing contributed packages on MacOS X: Solved!
I had run into problems when compiling some contributed packages to an
installation of R 1.40 by fink on MacOS X. Namely, packages KernSmooth
(2.22-7) and cluster (1.4-0) would not find required libraries, though those
were present on the system.
Jeff Whitaker, the maintainer of the R fink packages, kindly sent me this:
> Kaspar: It's not looking in /sw/lib, where the libs are (the
2000 Jun 22
1
R 1.1 congrat; undocumented behaviour of recordPlot
Hello,
first, I'd like to congratulate the core team to the new R version 1.1. I
think it's a great update, with glimpses into an even greater future
(tcltk!).
While playing around with the new functions (on Win 95), I found the
following:
As the documentation states, when I generate a plot and save it with
recordPlot, I can regenerate it by printing the variable:
> plot(1:10)
>
2001 Dec 19
2
How to create a data.frame "like" another, but longer?
Hello,
does anyone know of a quick way to create a data frame "like" another, but
with more rows?
What I'd like to do is this:
if mydata is a data.frame like
a b c
1 TRUE yes
2 FALSE no
3 TRUE yes
I'd like to get mydata2 with the same column names and column types, but
without the values and with more rows.
All I could think of was to manually do
2000 Mar 09
1
For the record: how to merge data frames vertically
Hello,
to save searching time in the S-news archive, here is the simple solution to
merge data frames vertically (cols must be equivalent, of course). The
frames must be components of a list, such as produced by
framelist<-split(bigframe,factor).
bigframe2<-do.call("rbind",framelist)
# posted to S-news by Bill Venables, found in summary message
2000 Feb 22
1
Follow-up: Inverse prediction with R?
(message from 22.2.2000 13:04 Uhr):
>
>
> Why don't you inverse the modelling instead:
>
> t.m.i <- lm((x~y)
>
Jan,
thanks for the tip, but it's not just the same. The coefficients come out
differently, since the squared y residuals are minimized. Orthogonal
regression would be symmetric, but least squares is not, I'm afraid. And,
what's more, I have to
2000 Feb 22
0
Inverse prediction with R?
Hello,
after some searching in the mailing list archives, R-Help and S-Plus-Help, I
dare asking the question here: How can I do inverse prediction from a lm
model with R?
What I want to achieve is this: predict term values for given new response
values. If I've got a model
t.m<-lm(y?x)
I would type something like
inverse.predict(t.m, newdata=data.frame(y=1:10))
which would give me new
2000 Feb 22
0
Another (last?) follow-up: Inverse Prediction with R
Hello,
after I've read a few answers from the list, I realised that I stated my
problem incorrectly: my x values are not _fixed_, as I wrote (I did not set
them). They just have no errors to them, but, apart from that, are random.
I think I shall be reading up on calibration next. Many thanks for the
references!
Kaspar
--
Kaspar Pflugshaupt
Geobotanisches Institut
Zuerichbergstr. 38
2000 Feb 25
0
Summary: Partial correlation coefficients in R. Thanks everybody!
Hello all,
here's a collection of answers I got on my question concerning partial
correlation coefficients:
Some people gave a simple formula for the three-variable-case, as did Dave
Lucy:
pcor <- function(v1, v2, v3)
{
c12 <- cor(v1, v2)
c23 <- cor(v2, v3)
c13 <- cor(v1, v3)
partial <- (c12-(c13*c23))/(sqrt(1-(c13^2)) * sqrt(1-(c23^2)))
2000 Jun 20
0
Pairwise comparisons/contrasts from a coxph model?
Hello,
this is probably more a statistical question than an R-specific problem, but
I'll risk it.
I've fitted a Cox Proportional hazard model with one factor Treatment (seven
levels) as a predictor variable. The general Null hypothesis (all groups
show the same survival behaviour) is clearly rejected. Now, is there any
(statistically sensible) way of doing pairwise comparisons and/or
2002 Jan 31
1
MacOS X: Packages KernSmooth and cluster won't compile
Hello,
I'm using R 1.40 on MacOS X X.1.2 (installed via the fink package manager).
To upgrade my installed packages, I tried to use update.packages() today.
All went well for most packages, with the exception of KernSmooth and
cluster. In both cases, libraries were not found although I think they are
present.
Here's what happened:
----------------------------------
>
2001 Aug 28
2
Estimating Weibull Distribution Parameters - very basic question
Hello,
is there a quick way of estimating Weibull parameters for some data points
that are assumed to be Weibull-distributed?
I guess I'm just too lazy to set up a Maximum-Likelihood estimation...
...but maybe there is a simpler way?
Thanks for any hint (and yes, I've read help(Weibull) ;)
Kaspar Pflugshaupt
--
Kaspar Pflugshaupt
Geobotanical Institute
ETH Zurich, Switzerland