Displaying 20 results from an estimated 600 matches similar to: "R and DBSCAN"
2011 Jul 13
7
Extraer datos mensuales de una serie temporal
Hola a todos
Estoy intentando extraer un subconjunto de datos de una serie temporal,
concretamente quiero extraer los meses de verano de varios años pero no
encuentro la manera. Los datos tienen este formato:
FECHA;H_SOLAR;DIR_M;DIR_S;VEL_M;VEL_S;VEL_X;U;V;TEMP_M;HR;BAT;PRECIP;RAD;UVA;UVB;FOG;GRID;
2011 Mar 04
3
Análisis de una serie temporal diaria
Hola a todos
Estoy tratando de analizaruna serie temporal con datos diarios de
temperaturas (40 años). He creado un objeto zoo (con ayuda de la lista,
gracias) sobre el que encuentro la regresión lineal. He probado también
a crear un objeto ts a partir del zoo. El problema que encuentro es que
nose puede aplicar la función stl para hallar la componente estacional y
la tendencia. Rdice que la
2010 Jun 14
1
Install Rmpi
Hi everyone
As I couldn't succeed with manual installation of Rmpi I decided to
start again from the beginning. I removed R and MPICH in my Ubuntu Hardy
installation. Then, to avoid any dependencies problems I have installed
MPICH and R from synaptic, not from sources. But now I can't install Rmpi.
An error message appears when trying to install Rmpi, you can find in
2008 Jun 23
2
Handle missing values
Hi everyone
I am new to R and have a question about missing values. I am trying to
do a cluster analysis of monthly temperatures and my data are 14 columns
with spatial coordinates (lat,lon) and 12 monthly values:
/lat - lon - temp1 - //temp2 - temp3 - .... - //temp12/
If I omit missing values (my missing values are 99.00) with
/mydata <- na.omit(mydata)/
every row with a
2001 Sep 25
2
glm.nb, anova.negbin
Dear R-collegues,
I'm getting an error message (Error in round) when summarising a glm.nb
model, and when using anova.negbin (in R 1.3.1 for windows):
> m.nb <- glm.nb(tax ~ areal)
> m.bn
Call: glm.nb(formula = tax ~ areal, init.theta = 5.08829537115498,
link = log)
Coefficients:
(Intercept) areal
3.03146 0.03182
Degrees of Freedom: 283 Total (i.e. Null); 282
2003 Apr 24
1
matrix to coordinates
Dear R-users,
I'm sure it must be a specific function or a better way to convert
matrix to x,y,z coordinates (and viceversa), than my function below (it
works). Any help?
m2coord <- function(m)
{
k <- nrow(m)*ncol(m)
aa <- data.frame(r=1:k, c=1:k, v=1:k)
k <- 0
for (i in 1:nrow(m))
for (j in 1:ncol(m))
{
k <- k+1
aa$f[k]=i; aa$c[k]=j; aa$v[k]=m[i,j]
}
aa
}
Juli
2007 Apr 25
1
Help with saptial analysis (cluster)
Hi R-users
I'm a beginner with R and statistics, so I need some help to start my data
analysis. I've been reading some docs and tutorials on R and cluster analysis.
I've got a large dataset (102000 points) with values of longitude, latitude and
temperature and want to see if I can find groups (clusters).
Following some tutorials I can look for principal components but get an error
2002 May 11
2
RODBC sqlFetch
Hi,
Thanks for showing me how to use RODBC and odbcConnect.
Now works nicely. The question I've got now is:
noms <- list.files(pattern=".DBF")
# removing extension names:
noms <- sapply(noms, function(x) as.character(strsplit(x,".DBF")) ,
USE.NAMES=F)
for (i in 1:length(noms)) {
s <- sqlFetch(bdades, noms[i])
# etc.
}
But it seems that sqlFetch()
2001 Dec 18
4
chi-squared test
I don't quite understand the difference between the two methods for
performing a chi-squared test on contingency tables: summary(table())
and chisq.test()
They may different results. E.g.:
aa <- gl(2, 10)
bb <- as.factor(c(1,2,2,2,1,2,1,2,2,2,1,2,2,2,1,1,1,2,1,1))
aa <- c(aa, aa)
bb <- c(bb, bb)
table(aa, bb)
summary(table(aa, bb))
chisq.test(aa, bb)
Could somebody give me
2011 Mar 04
1
Time series analysis for a daily series
Hi everyone
I am trying to do some time series analysis with daily temperature data
(40 years). I have created a zoo object and ts object but can't apply
stl function. It says the series is not periodic or has less than two
periods. I've searched through google and found a lot of messages about
this problem but not a solution/example to look for trend and seasonal
component of a
2005 Sep 26
1
merge maps from shapefile to lattice
Hi everybody:
Could anybody help how I solve the next problem?.
I'm doing interpolation maps of tropospheric ozone of my region, and after
create it using IDW, and kriging methods, I want from shapefiles (*.shx,
*.shp, *.dbf, *.sbx & *.sbn ) create contour over the interpolation maps.
Could anybody tell me how do it?.
Thanks in advance.
######################################
Antonio
2011 Feb 17
2
Regresión lineal para una serie temporal
Hola a todos
Estoy intentando hacer un análisis rápido de una serie temporal de datos
diarios pero me encuentro con algunos problemas. Me gustaría en primera
instancia hacer una regresión lineal pero no encuentro la forma.
Tras leer los datos diarios creo un objeto de la clase zoo y sobre éste
no puedo utilizar lm(). He leído algo sobre dynlm pero no encuentro la
forma.
Se agradece
2003 Dec 18
2
barplot & plot together
Dear colleges,
I'm trying to combine a barplot and a plot in a single figure as follows:
data <- 1:6
t <- barplot(data, axes=F)
par(new= T)
plot(t, data, type="b")
However, as you can see in the example, the dots of the second plot do
not fall in the midpoint of the bars in the first. Any trick for setting
the 2 plots at the same scale?
I have unsuccessfully tried:
plot(t,
2000 Mar 16
2
glm: offset in poisson
R-users,
Can an offset term be included in a Poisson model?
I get an error message when trying that:
>r3o <- glm(tax ~ areal + offset(o), family=poisson)
Error in (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y, :
inner loop 1; can't correct step size
In addition: Warning message:
Step size truncated due to divergence in: (if (is.empty.model(mt))
2010 Jun 08
1
Problem installing Rmpi
Hi everyone
I want to install Rmpi to use R in parallel mode in a Linux cluster
(Ubuntu, Hardy Heron). It seems to be properly installed but a problem
appears when loading Rmpi library.
R version 2.11.1 (2010-05-31)
> library("Rmpi")
Error: package 'Rmpi' was built before R 2.10.0: please re-install it
Should I remove R-2.11 and install R-2.10? I have tried to
2001 Sep 11
2
AIC
Dear R collegues,
I'm trying to understand what's AIC in R (ver. 1.3.1), and I'm getting a
different answer if I look at the AIC(of the fitted model) or the aic in
the summary( of the fitted model). Is this correct? Can somebody explain
me the difference between the two values? or Is the AIC criterion not
appropiated for Poisson models?
R session:
> t1 <- glm(tax ~ areal,
2001 Sep 11
2
AIC
Dear R collegues,
I'm trying to understand what's AIC in R (ver. 1.3.1), and I'm getting a
different answer if I look at the AIC(of the fitted model) or the aic in
the summary( of the fitted model). Is this correct? Can somebody explain
me the difference between the two values? or Is the AIC criterion not
appropiated for Poisson models?
R session:
> t1 <- glm(tax ~ areal,
2002 Jan 08
6
Subsets without NA
Is there a way of removing all rows with missing values from a data frame?
I usually use
subset(x, var1!="NA")
and repeat for each variable. It would be nice to be able to do it in one
fell swoop. Also, surprisingly, it doesn't always work. Sometimes I'm left
with an empty set even though not all rows have missing values for the
variable.
Cheers,
mikkel
Mikkel Grum,
2012 Dec 08
0
Dbscan Clustering Feature Question
Hello list. My apologies if this topic has been discussed before on the
list but I was unable to find it. I'm working on a way to cluster PCAP
files according to the events recorded within them. I've decided to use
Bro-IDS for feature extraction. I am looking at dbscan within the FPC
library to accomplish my goal.
Is it possible to feed a data frame to dbscan with more than two columns
2007 Jan 17
0
Does R implement DBSCAN , ROCK, BIRCH?
I saw that R language has a cluster package which has in built PAM, CLARA and Kmeans (and many more) Clustering Algorithms.
But, I couldnot find DBSCAN, ROCK, BIRCH algorithms (which I feel are standard ones). Aren't these implemented as well?
Bhanu Kalyan K
B.Tech Final Year, CSE
Tel: +91-9885238228
Alternate E-Mail:
reach4kalyan@gmail.com
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