Displaying 20 results from an estimated 5000 matches similar to: "Ellipse in PCA with parameters "a" and "b"defined."
2011 Jun 06
2
adding an ellipse to a PCA plot
Hi,
I created a principal component plot using the first two principal
components. I used the function princomp() to calculate the scores.
now, I would like to superimpose an ellipse representing the center
and the 95% confidence interval of a series of points in my plot (as
to illustrate the grouping of my samples).
I looked at the ellipse() function in the ellipse package but can't
get it
2013 Dec 04
2
AYUDA CON ERROR CON LA LIBRERIA PCA
Cordial saludo adjunto la base de datos y el script:
eu60<- read.csv(file.choose(), header=T, sep=";", dec=".", row.names=1)
eu60.pca <- PCA(eu60, quali.sup=19)
eu60.data <- cbind.data.frame(eu60[,19], eu60.pca$ind$coord)
eu60.ellipse <- coord.ellipse(eu60.data, bary=TRUE)
plot.PCA(ellipse=eu60.ellipse, cex=0.8)
El 4 de diciembre de 2013 17:35, Camilo Calle
2013 Dec 04
2
AYUDA CON ERROR CON LA LIBRERIA PCA
Cordial saludo, soy principiante en R y estoy haciendo un análisis
multivariado de datos, y necesito hacer las elipses de confianza donde la
variable 19 es cualitativa suplementaria y el resto son variables activas;
tengo el siguiente código:
eu60 <- read.csv(file.choose(), header=T, sep=";", dec=",", row.names=1)
### capturar datos
eu60.pca <- PCA(eu60, quali.sup=19) ##
2013 Dec 04
2
AYUDA CON ERROR CON LA LIBRERIA PCA
Hola, ¿qué tal?
Tu problema es que tienes agrupaciones de países (p.e., ASIA_MERIDIOL)
con un solo respresentante. Las matrices con las que construyes las
elipses son degeneradas (más bien, no existen: sospecho que tienen que
ver con la covarianza... ¿de un único caso?).
Elimina las agrupaciones triviales.
Un saludo,
Carlos J. Gil Bellosta
http://www.datanalytics.com
El día 4 de diciembre de
2011 May 28
2
Observation in a confidence ellipse
Hello everyone
I really need some help here. I made a confidence ellipse using the function ellipse from the package ellipse:
ellipse(SD, centre=colMeans(pcsref),t=sqrt((p * (n-1)/(n-p))*qf(0.99, p,n-p))
Now, I want to write a function whom return TRUE or FALSE if a given observation is in the confidence ellipse. But I have no clue how to do it
Can anyone help me?
Best regards
Jessica
2008 Sep 24
2
rgl: ellipse3d with axes
Last week I asked about data ellipses with rgl:::ellipse3d() with lines
showing the principal axes.
(The goal is a visual demonstration of PCA as a rotation of variable
space to component space.)
I was trying, unsuccessfully, to use princomp() to generate the PCA axes
and plot them using
segments3d:
> > PC <- princomp(trees)
> > sdev <- PC$sdev # component standard
2013 Jan 26
2
confidence / prediction ellipse
Hi,
I'm using the R library(car) to draw confidence/prediction ellipses in a
scatterplot.
>From what i understood the ellipse() function return an ellipse based
parameters: shape, center, radius .
If i read dataEllipse() function i can see how these parameters are
calculated for a confidence ellipse.
ibrary(car)
a=c(12,12,4,5,63,63,23)
b=c(13,15,7,10,73,83,43)
v <-
2013 Sep 15
1
DataEllipse versus Ellipse Function in R
Hi:
Does Ellipse and dataellipse function in R produce the same ellipse? I
wanted to see how the radius for the Ellipse function in R calculated. Also
what is the var-covariance matrix, if any, assumed for the dataellipse
function? Heres an example of the code where I am generating Multivariate
normal data and creating ellipse using the 2 functions:
library(car)
library(mvtnorm)
mu =
2009 Nov 01
1
Calculate Volume in a PCA
Hi,
my data frame consist of 8 Variables and 120 000 observations. With those datas I am running a PCA and after I want to calculate the Volume of the PCA-cloud of certain subsets of my data. Does anyone have an idea about a function that can do this?
Thanks
[[alternative HTML version deleted]]
2004 Nov 04
2
biplot drawing conc ellipses
Is there an option to draw concentration ellipses in biplots ? It seems
really nice to summarize large number of points of each group.
Cheers../ Murli
2011 Oct 17
1
plotting issues with PCA
Hi Listers,
This has a simple answer but it has been eluding me nonetheless.
I have been building a PCA plot from scratch with the ability to plot
predefined groups in different colors. This has worked fine but when I try
to get a polygon drawn around each of the groups it is not recognising my
colour file correctly and is only printing the first colour in the
file....code is below
2004 Oct 27
3
ploting an ellipse keeps giving errors
library (ellipse)
shape1 = c (1, 0, 0,1)
dim(shape1) = c(2,2)
ellipse (center = c(0,0), shape = shape1, radius = 1)
=============================
Error in plot.xy(xy.coords(x, y), type = type, col = col, lty = lty, ...) :
plot.new has not been called yet
It is really frustrating. Also what do the shape matrix, radius correspond to an ellipse function
(x-x0)^2/a + (y-y0)^2/b = 1
?
2003 Oct 28
2
Confidence ellipse for correlation
Hello,
SAS' point and click interface has the option of produce a scatterplot with a
superimposed confidence ellipse for the correlation coefficient. Since I
generally like R so much better, I would like to reproduce this in R. I've
been playing with the ellipse package. In order to have the points and the
ellipse on the same graph I've done the following.
(Load ellipse
2005 Sep 09
1
Plotting an ellipse in 3D
I have been using the ellipse function from the car package and the
covariance matrix to draw an ellipse around a group of points to show the
confidence limits. However, the points are actually represented by 3
variables so rather than plot each pairwise combination of variables in 2D I
would like to plot the 'ellipse' in 3D using the djmrgl package. Can anyone
offer advice on how I can
2011 Sep 27
1
Adding axis to an ellipse: "ellipse" package
Dear list members,
This might be a silly question but I just can't figure it out. I am using
the "ellipse" package on covariance matrices. I would simply like to plot my
ellipses WITH its two axis ploted as well. These axis represents the 2 eigen
vectors of my matrix and it is important that I can graphically show them.
Is there an easy way to do so?
Many thanks,
Antoine
--
View
2010 Sep 29
1
Fitting a half-ellipse curve
Dear mailing list,
I have following array:
X2 Y2
[1,] 422.7900 6.0
[2,] 469.8007 10.5
[3,] 483.9428 11.0
[4,] 532.4917 25.5
[5,] 596.1942 33.5
[6,] 630.8496 40.5
[7,] 733.2996 45.0
[8,] 946.4779 32.0
[9,] 996.8068 35.5
[10,] 1074.3310 23.0
I do afterwards the following:
plot.new()
plot.window(xlim=c(min(X1)-50,max(X1)+50),
2012 Feb 07
2
3D confidence ellipsoid with ellipse projections onto 2D plane
I have a 3xN matrix of parameters obtained from N regressions where the 3
parameters are jointly statistically significant. I would like to reproduce
a 3D confidence ellipsoid projecting 2D ellipses onto the XY plane as in
Figure 5.2 in this
2013 Oct 11
1
behaviour of read.xls (gdata package) when worksheet usesuser-defined cells formats
(I'm afraid this post didn't reach the list on last Wednesday, here it is again )
hi R-list,
And sorry for my frenglish !
I am running R < Good Sport > release ( i386-w64-mingw32/i386 (32-bit) ) ) under Windows 7 Professional, Service Pack 1.
My perl executable is ActivePerl build 817 [257965] (i.e. version 5.8.8.817). Usually it is working fine.
Using the gdata ::read.xls
2009 Apr 08
1
Is a point into an ellipse
Hi,
I drew an ellipse with the package ellipse. Now I would like to know if
a point is inside the ellipse. Is any R functions to do it without
computing the equation of the ellipse manually? Thanks.
For example, if I do "plot(ellipse(0.8), type = 'l')", I would like to
know if (0,1) belongs to the drawn ellipse.
Regards,
Alain
--
Alain Guillet
Statistician and Computer
2010 Mar 28
3
Ellipse that Contains 95% of the Observed Data
I can take the results of a simulation with one random variable and generate
an empirical interval that contains 95% of the observations, e.g.,
x <- rnorm(10000)
quantile(x,probs=c(0.025,0.975))
Is there an R function that can take the results from two random variables
and generate an empirical ellipse that contains 95% of the observations,
e.g.,
x <- rnorm(10000)
y <- rnorm(10000)
?