Displaying 20 results from an estimated 70 matches for "phhs80".
2006 Aug 03
3
Looking for transformation to overcome heterogeneity of variances
...that the variances are not equal, and therefore I have
tried to apply the classical transformations to have homocedasticity
in order to be able to use ANOVA. Unfortunately, no transformation
that I have used transforms my data into data with homocedasticity.
The histogram of variances is at
http://phhs80.googlepages.com/hist1.png
Is someone able to suggest to me a transformation to overcome the
problem of heterocedasticity?
Thanks in advance,
Paul
2007 Sep 07
3
Delete query in sqldf?
Dear All,
Is sqldf equipped with delete queries? I have tried delete queries but
with no success.
Thanks in advance,
Paul
2009 Sep 26
1
Problem with downloading workspace file from a web address
...ce/file")
However, if the path to the saved workspace file is a web address, one
gets the following error:
?Error in readChar(con, 5L, useBytes = TRUE) : cannot open the connection
In addition: Warning message:
In readChar(con, 5L, useBytes = TRUE) :
cannot open compressed file
'http://phhs80.googlepages.com/workspace20090922', probable reason 'No
such file or directory'?
To circumvent this problem, one can download the saved workspace file
to a local folder with download.file() and the option
mode="wb"
active.
My question is: Should not load() have the same mo...
2009 Jul 23
4
How to avoid control-c killing the open program?
Dear All,
When I am running a program under Wine and I press Control-C, the running program is killed. However, this behavior is not always the desired one. In truth, imagine that the program is doing some calculations that you want to interrupt; if one presses Control-C, the program is killed, but all one wanted was to interrupt the calculations and NOT killing the program. Is there some
2010 Jul 26
7
Bug on r-bc?
Dear All,
The following code should return 1, but it returns 0:
source("http://r-bc.googlecode.com/svn/trunk/R/bc.R")
bc("9 % 2")
Do you confirm this bug?
Paul
2007 Nov 24
5
Dot plots in R
Dear All,
Can R produce dot plots like the one of the following picture:
http://en.wikipedia.org/wiki/Image:Dotplot_of_random_values.png
?
I have tried dotchart, but no success.
Thanks in advance,
Paul
2007 May 07
3
Bad optimization solution
Dear All
I am trying to perform the below optimization problem, but getting
(0.5,0.5) as optimal solution, which is wrong; the correct solution
should be (1,0) or (0,1).
Am I doing something wrong? I am using R 2.5.0 on Fedora Core 6 (Linux).
Thanks in advance,
Paul
------------------------------------------------------
myfunc <- function(x) {
x1 <- x[1]
x2 <- x[2]
abs(x1-x2)
}
2008 Jan 07
7
Can R solve this optimization problem?
Dear All,
I am trying to solve the following maximization problem with R:
find x(t) (continuous) that maximizes the
integral of x(t) with t from 0 to 1,
subject to the constraints
dx/dt = u,
|u| <= 1,
x(0) = x(1) = 0.
The analytical solution can be obtained easily, but I am trying to
understand whether R is able to solve numerically problems like this
one. I have tried to find an
2006 Nov 23
4
Ryacas and fractions with simultaenously very large numerators and denominators
Dear All
I am doing the following:
> x <- yacas("3/2")
> for (i in 2:400)
+ x <- yacas(paste(x,"*",x))
> x
expression(Inf^1.260864167e+117/Inf^6.304320836e+116)
> Eval(x)
[1] NaN
No luck this way. However, I am successful with
> y <- yacas("(3/2)^400")
> y
expression(7.05507910865533e+190/2.58224987808691e+120)
> Eval(y)
[1]
2007 Nov 18
2
Getting theta in italic in a plot
Dear All,
Consider the following code:
plot(0,0)
text(0,0.5,expression(italic(theta)))
I would like to get theta in italic, but I always get it upright. Any
suggestions?
Thanks in advance,
Paul
2006 Aug 26
4
Can R compute the expected value of a random variable?
Dear All
Can R compute the expected value of a random variable?
Thanks in advance,
Paul
2011 Aug 04
3
Automatic creation of binary logistic models
Dear All,
Suppose that you are trying to create a binary logistic model by
trying different combinations of predictors. Has R got an automatic
way of doing this, i.e., is there some way of automatically generating
different tentative models and checking their corresponding AIC value?
If so, could you please direct me to an example?
Thanks in advance,
Paul
2007 Sep 11
6
Editor for R under Fedora 7
Hello everyone,
I wanted to ask what will be a good editor to write R scripts in Fedora 7.
Tony
[[alternative HTML version deleted]]
2006 Jun 13
8
MS Access2000 does not work fine
Dear All
I am using Wine 0.9.15 on Fedora Core 5 in connection with WineTools.
However, when I create a new database on MS Access (from MS
Office2000), I get the following error:
"The Dynamic Link Library msjet40.dll could not be located".
So, I cannot use MS Access under Wine.
Any ideas?
Thanks in advance,
Paul
2018 May 08
1
Cannot install package bibliometrix on F28
Dear All,
I am trying to install the package bibliometrix on F28, but getting thsi error:
-------------------
** preparing package for lazy loading
Error in dyn.load(file, DLLpath = DLLpath, ...) :
unable to load shared object '/usr/lib64/R/library/leaps/libs/leaps.so':
libgfortran.so.4: cannot open shared object file: No such file or directory
ERROR: lazy loading failed for package
2006 May 18
2
Classification trees and written conditions
Dear All
When drawing a classification tree with
plot(mytree)
text(mytree)
the conditions are written just before the nodes branch. My question
is: can one be certain that those conditions refer to the left-side
branches? (The R documentation surprisingly lacks the information that
I am asking for.)
Thanks in advance,
Paul
2006 Nov 23
3
Conversion from expression to numeric
Dear All
I am trying to convert from the type "expression" to the type
"numeric". The following works:
> x <- expression(6.2)
> as.numeric(as.character(x))
[1] 6.2
However, the following does not work:
> x <- expression(62/100)
> as.numeric(as.character(x))
[1] NA
Warning message:
NAs introduced by coercion
Any idea about how to deal with the second case?
2007 Apr 04
1
Cannot install iWidgetsRGtk
Dear All
I am trying to install iWidgetsRGtk (on a Linux machine), but getting
the following error:
> install.packages("iWidgetsRGtk",repos="http://www.math.csi.cuny.edu/pmg")
Warning in download.packages(unique(pkgs), destdir = tmpd, available =
available, :
no package 'iWidgetsRGtk' at the repositories
>
Any ideas?
Thanks in advance,
Paul
2007 Nov 18
1
Exporting a plot with the LaTeX font lmodern
Dear All,
I would like to export, as a pdf file, a plot with the LaTeX font
lmodern as the font of my graph. Could somebody please help me?
Thanks in advance,
Paul
2007 Nov 28
1
Histograms and Sturges rule
Dear All,
According to the Sturges rule, the number of classes of a histogram is
the closest integer to
1 + logb(n,base=2)
where n is the number of observations. The function hist(), by
default, uses the Sturges rule. However, the code
x <- 1:200
hist(x)
produces a histogram with 10 classes and not 9 classes as determined
by the Sturges rule. What am I missing?
Thanks in advance,
Paul