Displaying 20 results from an estimated 2000 matches similar to: "Finding local maxima (height) in a matrix data (6 spatial coordinates)?"
2008 Feb 14
1
Any mountain clustering method in R?
Dear all,
I wonder which R algorithm could perform a mountain clustering in an spatial
grid, in other words, having the coordinates of a map (x,y ... or even more)
and then the altitude/height at each point I would like to localise the
peaks of that topological surface. Which R algorithm can perform this? I see
it as a clustering problem where the peak should be at the center of each
cluster.
2008 Jul 02
1
Usage of rJava (.jcall) with Weka functions, any example?
Dear All,
I'd like to use Weka functions that are not implemented (do not have
interface) in RWeka, like the Remove function and others in the
future!
The .java() functionality is for that purpose but I haven't seen any
example with Weka functions. Could anyone give me hand in how to do
it? For instace if I want to use the
weka.filters.unsupervised.attribute.Remove?
1. in the R console,
2008 Jul 07
2
Colour clusters in a 2d plot
R experts,
I have three columns. c1 and c2 are numeric variables whereas c3 are the
clusters classes (nominal variable, 10 different: cluster1, cluster2,
cluster3, cluster4, cluster5 ....). I'd like to plot c1 against c2 (easy!)
in a 2D plot and put different color depending to the cluster class
automatically regardless the number of clusters.
Could anyone give a hand?
Josep Maria,
matrix
2005 Aug 03
0
possibility of R/Maxima linking
Hello,
I'm aware that recently there has been discussion of R joining forces with
an algebra system in some way. Here is my $0.02.
I suggest linking R with Maxima (http://maxima.sf.net).
Maxima is written in Lisp. Maxima objects are pretty simple.
Maxima works on expressions, and almost every expression
is a Lisp list of the form ((op) arg1 arg2 arg3 ...) which
associates an operator and
2007 Nov 19
0
Using density() and turnpoint to Identify maxima in data
Hi
I have a large dataset which follows a multimodal distribution. And I
would like to identify the maxima. As the data is obtained from a
stochastic simulation, not all maxima in the data are "real maxima of
the dirstribution" but rather small random fluctuations. Unfortunately,
it is not possible for me to run more simulations to smooth the obtained
distribution.
What I am doing
2004 Mar 09
2
maxima
Dear all,
suppose I have a bi-variate function f(x,y), I want to find the maxima. I
define x and y vector, and get matrix z=f(x,y). how can I get which (x0,y0)
makes z become the maxima?
I can do two loops to get the x0 and y0, but I think there may exist a
function to do this.
2017 Aug 26
0
Find maxima of a function
> On 26 Aug 2017, at 16:39, niharika singhal <niharikasinghal1990 at gmail.com> wrote:
>
> Hi,
>
> Thanks for your mail, and time
>
> It is not working for some arguments, when mean value is like >6.
>
>
> case
>
> mc0 <- c(0.08844446,0.1744455,0.1379778,0.1209769,0.1573065,0.
> 1134463,0.2074027)
>
> rv
2009 Jan 31
9
Maxima and Ruby Integration
I''m looking to write a javascript heavy clientside program with a
something serverside backend that connects to the free maxima math
program. I have extensive knowledge of ruby on rails, so I would prefer
to call Maxima with ruby, but I don''t know if this is even possible. Its
fairly easy to call Maxima (with a lisp implementation) using ANSI C, it
is a little less easy to
2013 Mar 20
0
unexpected local minima/maxima with surf.gls
Hi there,
I use the surf.gls() function to fit a variable measured over a surface. When I plot the predicted surface, there are local minima/maxima in almost every coordinate where data were measured, which seems aberrant. For instance:
?? x <- c(343,293,343,243,293,343,443,543,593,243,293,343,393,443,493,543,593,143,193,243,293,343,393,443,
2017 Aug 27
0
Fwd: Find maxima of a function
Dear Niharika,
As I said before, the problem is basically an optimization issue. You should isolate the problematic part from the rest of your study. Sometimes, more information does not help to solution. All the answers from us (Ulrik, David, me) are more or less are correct to find a maximum point. Newton?s method is also correct. But after answers, you only say, it didn?t find the right
2017 Aug 27
1
Fwd: Find maxima of a function
I have not followed the history of this thread, but I am quite flummoxed as to why the OP is rewriting code to estimate parameters from an univariate Gaussian mixture model when alternatives such as EMCluster (which generally appears to handle initialization better than MClust) exist. Or perhaps there is more to it in which case I apologize. But I thought that I would make the OP aware of the
2017 Aug 27
2
Fwd: Find maxima of a function
---------- Forwarded message ----------
From: niharika singhal <niharikasinghal1990 at gmail.com>
Date: Sun, Aug 27, 2017 at 11:57 AM
Subject: Re: Find maxima of a function
To: "David Winsemius [via R]" <ml+s789695n4745009h56 at n4.nabble.com>,
"Ismail SEZEN [via R]" <ml+s789695n4744993h60 at n4.nabble.com>, Ulrik Stervbo
<ulrik.stervbo at gmail.com>
2008 Dec 19
0
How to plot arrows for a PLS plot with ggplot2?
Dear community,
I'd like to build a PLS plot with scores and loadings, sometimes
called "biplot". Like in biplot.mvr {pls} but using ggplot2.
1. Scores plot. No problem!
ggplot(data=data1,aes(x=plsr1,y=plsr2))+geom_point(aes(colour=solenergy,shape=type))+geom_text(aes(label=res,size=1,hjust=0,vjust=0))
where,
> str(data1)
'data.frame': 295 obs. of 5 variables:
$
2012 May 03
2
Finding local maxima on a loess surface
If a run a LOESS model and then produce a smoothed surface: Is there any
way to determine the coordinates of the local maxima on the surface?
[[alternative HTML version deleted]]
2017 Aug 26
0
Find maxima of a function
Please keep the list in cc.
Sorry, it didn't work as expected. Maybe someone else have an appropriate
solution.
Best,
Ulrik
On Sa., 26. Aug. 2017, 12:57 niharika singhal <niharikasinghal1990 at gmail.com>
wrote:
> Hi
>
> Thanks for you mail,
> I really appreciate your time on my problem
>
> I have posted this problem on
>
>
>
2017 Aug 26
6
Find maxima of a function
I have a Gaussian mixture model with some parameters
mean=(506.8644,672.8448,829.902)
sigma=(61.02859,9.149168,74.84682)
c=(0.1241933, 0.6329082, 0.2428986)
And the plot look something like below.[image: enter image description here]
<https://i.stack.imgur.com/4uUQ9.png>
Also, if I change my parameters to
mean=(2.15,2.0,2.9)
sigma=(0.1,0.1,0.1)
c=(1/3,1/3,1/3)
Then plot would change
2005 Jun 15
1
Finding local minima and maxima
I have data in the form of (x,y) pairs and would like to find local
minima and maxima (typically the zeros of the 2nd derivative) of the y
values. I looked at numericDeriv, but I don't have an "expression" per
se. I looked at optim, also, but it looks like it will find only one
"global" max or min. I can code up my own piecewise derivatives, but
wondered if there is
2008 Jan 07
3
Seeking a more efficient way to find partition maxima
Hi.
Suppose I have a vector that I partition into disjoint, contiguous subvectors. For example, let v = c(1,4,2,6,7,5), partition it into three subvectors, v1 = v[1:3], v2 = v[4], v3 = v[5:6]. I want to find the maximum element of each subvector. In this example, max(v1) is 4, max(v2) is 6, max(v3) is 7. If I knew that the successive subvector maxima would never decrease, as in the example,
2017 Aug 26
1
Fwd: Find maxima of a function
Hi,
Thanks for your mail, and time
It is not working for some arguments, when mean value is like >6.
case
mc0 <- c(0.08844446,0.1744455,0.1379778,0.1209769,0.1573065,0.
1134463,0.2074027)
rv <-UnivarMixingDistribution(Norm(486.4255, 53.24133),
Norm(664.0713, 3.674773),
Norm(669.0484, 4.101381),
2010 Mar 17
1
Is there any R package that can find the maxima of a 1-D time series
Is there any R package that can help me with digging out the maxima of a 1-D trajectory ?
I have 975 1-D curves. They are only known as time series. That is a set of points ordered with respect
to time. Some curves exhibit one only peak. Others have two peaks of different height.
We wish to find the number of peaks and their position along the time axis.
Apparently it's a trivial problem