Displaying 20 results from an estimated 32 matches for "isella".

2012 Oct 05

2

Test for Random Points on a Sphere

Dear All,
I implemented an algorithm for (uniform) random rotations.
In order to test it, I can apply it to a unit vector (0,0,1) in Cartesian
coordinates.
The result is supposed to be a set of random, uniformly distributed,
points on a sphere (not the point of the algorithm, but a way to test it).
This is what the points look like when I plot them, but other then
eyeballing them, can anyone

2011 Dec 15

3

From Distance Matrix to 2D coordinates

Dear All,
I am struggling with the following problem: I am given a NxN symmetric
matrix P ( P[i,i]=0, i=1...N and P[i,j]>0 for i!=j) which stands for the
relative distances of N points.
I would like use it to get the coordinates of the N points in a 2D
plane. Of course, the solution is not unique (given one solution, I can
translate or rotate all the points by the same amount and generate

2010 Jul 19

1

Hurst Exponent Estimation

Dear All,
I am a novice when it comes to time-series analysis and at the moment I
am actually interested in calculating the Hurst exponent of a time
series.
This question has already been asked quite some time ago
http://bit.ly/98dZsi
and I trust some progress has been made ever since.
I was able to find some functions in the packages

2013 Jan 28

1

RandomForest and Missing Values

Dear All,
I would like to use a randomForest algorithm on a dataset.
The set is not particularly large/difficult to handle, but it has some
missing values (both factors and numerical values).
According to what I found
https://stat.ethz.ch/pipermail/r-help/2005-September/078880.html
https://stat.ethz.ch/pipermail/r-help/2007-January/123117.html

2016 Apr 19

0

Problem with X11

I don't have my debian box available so can't confirm. But I would try
$apt-get install libpng
On Tue, Apr 19, 2016 at 11:23 AM, Lorenzo Isella <lorenzo.isella at gmail.com>
wrote:
> Dear All,
> I have never had this problem before. I run debian testing on my box
> and I have recently update my R environment.
> Now, see what happens when I try the most trivial of all plots
>
> plot(seq(22))
>>
> Error in (...

2016 Apr 19

3

Problem with X11

Dear All,
I have never had this problem before. I run debian testing on my box
and I have recently update my R environment.
Now, see what happens when I try the most trivial of all plots
> plot(seq(22))
Error in (function (display = "", width, height, pointsize, gamma, bg,
:
X11 module cannot be loaded
In addition: Warning message:
In (function (display = "", width,

2017 Nov 07

0

Fitdistrplus and Custom Probability Density

...ight require some fiddling
e.g.
d <- function(x) { exp(-x^2/2)/(sqrt(2*pi)) } # just an example for you to
test with; use your own density d(x) in your case
Then define myCumDist, myQuantile as above and compare with pnorm, qnorm.
HTH,
Eric
On Tue, Nov 7, 2017 at 4:22 PM, Lorenzo Isella <lorenzo.isella at gmail.com>
wrote:
> Dear All,
> Apologies for not providing a reproducible example, but if I could, then I
> would be able to answer myself my question.
> Essentially, I am trying to fit a very complicated custom probability
> distribution to some data.
>...

2017 Nov 07

2

Fitdistrplus and Custom Probability Density

Dear All,
Apologies for not providing a reproducible example, but if I could, then I
would be able to answer myself my question.
Essentially, I am trying to fit a very complicated custom probability
distribution to some data.
Fitdistrplus does in principle everything which I need, but if require me
to specify not only the density function d, but also the cumulative p and
and inverse cumulative

2018 Apr 18

3

Reasons to Use R in a Public Administrations and Ideas for a Short Training

Dear All,
Ages ago I posted to this mailing list asking for advice about to
evangelize the use of R in an international public
administration where the fact that R is free is not a decisive factor
(actually its being "freeware" may even be seen negatively). After a
long time, I think it is worthwhile asking the question again and see
what suggestions other users have.
Another question

2009 Apr 01

1

Latex symbols in R (\perp and \parallel)

Dear All,
I am sure this is a one-liner, but I cannot find the R command to
generate the LaTex symbols \perp and \parallel. Consider for instance
the figure
(one can use any kind of data for the plot)
pdf("friction_linear_chain_perpendicular.pdf")
par( mar = c(4.5,5, 2, 1) + 0.1)
plot(data[ ,1], data[

2010 Jun 23

5

Plotrix Trick

Dear All,
I am using the plotrix library to plot some matrices.
I have a problem: some of my data are outliers, hence using a linear
color scale does not work very well (you would see too many cells having
a similar, indistinguishable color). See the code snipped at the end of
the email.
Plotting the logarithm of the data gets the job done, but my problem is
that I would like to write in every

2007 Mar 01

2

function with Multiple Output

Dear R user,
I have a simple question for you: I have created a global function that
evoke other subsidiary functions. when I run the global function I want
to store the outcomes of the of each subsidiary function into a
variables. an examples
my.fun=function(vector, index){
a=fun.a(vector, index)
b=fun.b(vector, index)
}
if i use return() I can only retrive one single results.

2012 Feb 19

1

World Heat/Rainbow Map

Dear All,
I would like to do the following: make a plot of the world and color a few selected states.
Some states have an associated scalar (i.e a simple number) and I would like to paint them using a heat map and show legend for the color map in the plot. One or two states do not have any number associated to them and are simply colored/filled according to a distinctive pattern that I choose.

2013 Mar 24

1

Random Forest, Giving More Importance to Some Data

Dear All,
I am using randomForest to predict the final selling price of some items.
As it often happens, I have a lot of (noisy) historical data, but the
question is not so much about data cleaning.
The dataset for which I need to carry out some predictions are fairly
recent sales or even some sales that will took place in the near future.
As a consequence, historical data should be somehow

2017 Dec 21

1

Fitting Beta Distribution

Dear All,
I need to fit a custom probability density (based on the symmetric beta
distribution B(shape, shape), where the two parameters shape1 and shape2
are identical) to my data.
The trouble is that I experience some problems also when dealing with the
plain vanilla symmetric beta distribution.
Please consider the code at the end of the email.
In the code, dbeta1 is the density of the beta

2017 Dec 21

0

Fitting Beta Distribution

...tor is also a function of the parameters I want to optimise, hence I
should write
dbeta2 <- function(x, shape){
res <- x^(shape-1)*(1-x)^(shape-1)/beta(shape, shape)
return(res)
}
after which the results are consistent.
---------- Forwarded message ----------
From: Lorenzo Isella <lorenzo.isella at yopmail.com>
Date: 21 December 2017 at 11:29
Subject: Fitting Beta Distribution
To: "r-help at r-project.org" <r-help at r-project.org>
Dear All,
I need to fit a custom probability density (based on the symmetric beta
distribution B(shape, shape), where th...

2017 Jun 25

1

rJava Broken on Linux + R 3.4

Dear All,
I think there is something wrong with rJava on any Debian based
distribution.
I may be wrong, but I experiencing exactly the problems mentioned at
https://github.com/amattioc/SDMX/issues/130
and at
https://github.com/s-u/rJava/issues/110
A couple of packages (RJSDMX and xlsx) are now impossible to install
on my debian stretch platform

2011 Feb 25

2

Visualizing Points on a Sphere

Dear All,
I need to plot some points on the surface of a sphere, but I am not sure
about how to proceed to achieve this in R (or if it is suitable for this
at all).
In any case, I am not looking for really fancy visualizations; for
instance you can consider the images between formulae 5 and 6 at
http://bit.ly/hOgK9h
Any suggestion is appreciated.
Cheers
Lorenzo

2016 Apr 19

0

Problem with X11

...???? [11] LC_MEASUREMENT=de_DE.UTF-8??? LC_IDENTIFICATION=de_DE.UTF-8attached base packages:[1] stats???? graphics? grDevices utils???? datasets? methods?? base???? other attached packages:[1] rkward_0.6.1loaded via a namespace (and not attached):[1] tools_3.0.2Best regards,Markus HofstetterLorenzo Isella <lorenzo.isella at gmail.com> schrieb (19.04.2016 17:23):Dear All,
I have never had this problem before. I run debian testing on my box
and I have recently update my R environment.
Now, see what happens when I try the most trivial of all plots
> plot(seq(22))
Error in (function (display =...

2012 Dec 30

3

Odds Ratio and Logistic Regression

Dear All,
I am learning the ropes about logistic regression in R.
I found some interesting examples
http://bit.ly/Vq4GgX
http://bit.ly/W9fUTg
http://bit.ly/UfK73e
but I am a bit lost.
I have several questions.
1) For instance, what is the difference between
glm.out = glm(response ~ poverty + gender, family=binomial(logit),
data=mydata)
and
glm.out =